Dear Friends and Colleagues,
This is our fourth annual scientific workshop focussing on essential and detrimental elements entering the food chain via plants. We are glad to observe that more than 80 scientists from nearly 30 countries within and outside Europe will present their recent results on various topic of the workshop.
To strengthen the outcome of our workshop we have invited the leading experts from different corners of the world as keynote speakers in the fields of plant nutrition, plant biology and genomics, biotechnology, food processing, nutritional physiology and human nutrition.
We are grateful for support from our sponsors for the conduction of this workshop.
On behalf of the Organizing Committee,
Best wishes to everyone for an interesting and inspiring workshop
LOCAL ORGANIZING COMMITTEE
Bal Ram Singh, UMB
Peder Lombnæs, BIOFORSK Anja Nieuwenhuis, UMB Liv Korslund, UMB
Anne Elisabeth Munkeby, UMB Signe Dahl, UMB
ORGANIZING SECRETARY
LIV KORSLUND,UMB - E-MAIL:[email protected]
4 COSTACTION FA0905
Mineral Improved CROP PRODUCTION FOR HEALTHY FOOD AND FEED
PROF.DR.BAL RAM SINGH,MCCHAIR
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
PROF.DR.PETER SCHRÖDER,MCVICE CHAIR
HELMHOLTZ-ZENTRUM MÜNCHEN,GERMAN
RESEARCH CENTER FOR ENVIRONMENTAL HEALTH ([email protected])
COSTFA0905 AIMS AT:
• identify bottlenecks limiting the content of bioavailable minerals (Fe, Zn, Mg, Se) in the consumable crop part
• provide solutions for 3-fold increase in bioavailable food/feed mineral content
• assess ways to limit the entry of Cd and As into the food chain
• disseminate this knowledge to stakeholders and the public. European dimension and added values COST
COSTFA0905 WILL STRIVE TO:
• maximise European synergy in research cooperation
• provide innovative ideas to improve the mineral status of food and feed
• find methods to exploit genetic variability of food and fodder crops
• enhance scientific know how to improve minerals in food under modern processing
• create training and exchange programs, for students, postdoctoral fellows and young researchers, especially women
• identify key institutes and personnel for efficient assessment of food and feed mineral quality across Europe
P ROGRAMME
16:00 - 18:00 Arrival and Check-in the hotel or Pentagon
MONDAY JUNE 10TH
08:15 - 09:00 REGISTRATION –BIOTECHNOLOGY BUILDING -
09:00 - 10:00 BIOTECHNOLOGY BUILDING –AUDITORIUM ARABIDOPSIS
OPENING CEREMONY
Hans Fredrik Hoen, Rector,
Norwegian University of Life Sciences (UMB) Nils Vagstad, Director of Research,
Norwegian Institute for Agricultural and Environmental Research (BIOFORSK)
Øystein Johnsen, Head of the Department, Plant and Environmental Sciences, UMB
Chair: Bal Ram Singh Cost Action FA0905
10:00 - 17:30 WORKING GROUP 1(WG1) Chair: Ismail Cakmak
Rapporteur: Michel Mench
10:00 - 10:30 KEYNOTE: Availability of
micronutrients and undesirable trace elements in the soil-plant-microbe continuum
Zed Rengel
University of Western Australia, Perth, Australia
10:30 - 10:50 Transformation of As-species between cultivation medium and plants
Tommy Landberg and M. Greger
Department of Ecology, Environment and Plant Sciences, Stockholm University, Sweden
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10:50 - 11:10 Decreasing of cadmium in wheat grain depends on the form of the applied zinc
Zdenko Lončarić,
Maja Manojlović, Brigita Popović, Krunoslav Karalić, Ranko Čabilovski, Vladimir Ivazić, Espen Govasmark, Bal Ram Singh
Faculty of Agriculture in Osijek,
Kralja Petra Svačića 1d, HR–31000 Osijek, Croatia
11:10 - 11:40 Coffee Break
11:40 - 12:00 Agriculture activities and their input on keeping the entry of cadmium into the food chain
Marta Pogrzeba,
Aleksandra Sas-Nowosielska, Ewa Gucwa-
Przepióra, Eugeniusz Małkowski and Jacek Krzyżak Institute for Ecology of Industrial Areas Katowice, Poland
12:00 - 12:20 Selenium cycle in field ecosystem Mervi M. Seppänen,
Nashmin Ebrahimia, Anthony Owusu-Sekyere and Helinä Hartikainen
Department of Agricultural Sciences, University of Helsinki, Finland
12:20 - 14:00 Lunch
14.00 - 16:20 WORKING GROUP 1(WG1) Chair: Rainer Schulin Rapporteur: Elena Comina
14:00 - 14:30 KEYNOTE:Understanding zinc bioavailability to plants
Ellis Hoffland and Andreas Duffner
Wageningen University, Dept. Soil Quality, The Netherlands
14:30 - 14:50 Effects of diffusion limitations of zinc fluxes into wheat root , DGT, and PLM devices in presence of organic ligands
Anja Gramlich,
Susan Tandy, Emmanual Fossard, Jost Eikenberg and Rainer Schulin
Institute of terrestrial Ecosystems, ETH, Zurich, Swtizerland
on soil zinc content and availability R. Schulin, P. Mäder, J. Mayer, M. Mazzoncini and E. Frossard
Institute of Agricultural Sciences, Group of Plant Nutrition, ETH Zurich, Switzerland
15:10 - 15:30 Effect of intercropping systems and fertilizers on maize and soybean grain composition
Vesna Dragicevic,
Oljaca Snezana, Dolijanovic Zeljko, Stojiljkovic Milovan, Spasojevic Igor and Nisavic Marija Maize Research Institute,Belgrade, Serbia
15:30 - 15:50 Improved uptake of mineral nutrients by intercropped forage maize and faba beans
Eva Stoltz
The Rural Economy and Agricultural Society, Örebro, Sweden
15:50 - 16:20 Coffee Break
16:20 - 18:20 POSTER SESSION 1 Chair: Maria Greger
Rapporteur: Peder Lombnæs
TUESDAY JUNE 11TH
09:00 - 15:00 WORKING GROUP 2(WG2) Chair: Danuta Maria Antosiewicz Rapporteur: Rolf Herzig
09:00 - 09:30 KEYNOTE: Cellular iron pools:
localization and mobilization by specialized transporters
Catherine Curie
Hannetz Roschzttardtz, Fanchon Divol, Daniel Couch, Mathilde Séguéla, Louis Grillet, Geneviève Conéjéro and Stéphane Mari
Laboratoire de Biochimie et Physiologie Moléculaire Végétale, CNRS-INRA, Montpellier, France
8
09:30-09:50 Analysis of a zinc-sensor function in the Arabidopsis bZIP19/23
transcription factors
Ana G.L. Assunção,
Mark G.M. Aarts, Pai Pedas, Daniel P Persson, Søren Husted and Jan Kofod Schjoerring University of Porto, Vila do Conde, Portugal
09:50 - 10:10 Natural variation of Arabidopsis thaliana hapmap population reveals candidate genes controlling zinc deficiency tolerance
Ana Carolina Atala Lombelo,
Charles Neris Moreira, David E Salt and Mark G.M. Aarts
Wageningen University, Wageningen, The Netherlands
10:10 - 10:30 Capturing unprecedented natural diversity in plant metal
accumulation: a comprehensive survey of european Arabidopsis halleri populations
Stephan Clemens
Stephan Höreth, Ricardo Stein and Ute Krämer Department of Plant Physiology, University of Bayreuth, Germany
10:30 - 10:50 Translocation of copper from roots to shoots is mediated by OsHMA5 in rice
Fenglin Deng,
Ikuko Yonamine, Naoki Yamaji and Jian Feng Ma Institute of Plant Sciences and Resources, Okayama University, Japan
10:50 - 11:20 Coffee Break
11:20 - 15:10 WORKING GROUP 2(WG2) Chair: Nathalie Verbruggen Rapporteur: Sylvain Legay
11:20 - 11:50 KEYNOTE: Transporters involved in Cd accumulation in rice
Jian Feng Ma
Institute of Plant Science and Resources, Okayama University, Japan
11:50 - 12:10 Reaction of root cells to cadmium Alexander Lux
Conenius University, Bratislava, Slovakia
12:10 - 13:40 Lunch
accumulation in plants Andrea Nesler and Giovanni DalCorso, Università di Verona, Italy
14:00 - 14:20 Modification of Fe-Zn-Cd cross- homeostasis through transformation contributes to changes in the
tolerance to metals
Katarzyna Tracz,
Holger Schmidt, Stephan Clemens and Danuta Maria Antosiewicz
University of Warsaw, Faculty of Biology, Warsaw, Poland
14:20 - 14:40 Silicon alleviates cadmium-induced oxidative stress in maize
Marek Vaculík,
Miroslava Luxová and Alexander Lux University of Bratislava, Slovakia
14:40 - 15:10 Coffee Break
14:40 - 16.00 Core Group meeting
15:10 - 17:10 POSTER SESSION 2 Chair: Peter Schröder
Rapporteur: Maria J Poblaciones
17:30 Bus from Biotech Building, UMB to the ferry to Oscarsborg
19:00 - Reception and Conference dinner – Banquet at Oscarsborg Ferry returns Drøbak at 23:00 - Bus to Ski via Ås
10 WEDNESDAY JUNE 12TH
09:00 - 15:00 WORKING GROUP 3(WG3) Chair: Richard Hurrell
Rapporteur: Gerd Elisabeth Vegarud
09:00 - 09:30 KEYNOTE: Biotechnological approaches to the iron biofortification of rice
Navreet K. Bhullar
Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
09:30 - 10:00 KEYNOTE:Iron bioavailability in humans from plant ferritin
Bo Lönnerdal
Department of Nutrition, University of California, Davis, USA
10:00 - 10:20 Iron bioavailability from low phytic acid common beans (Phaseolus vulgaris L.) is increased in young women
Nicolai Petry,
Ines Egli, Bruno Campion, Erik Nielsen and Richard Hurrell
Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
10:20 - 10:40 Comparison of the speciation, digestibility, and bioavailability of iron in fortified and unfortified unleavened breads of different cultivars and extraction rates
Tristan Eagling,
Anna Wawer, Fangjie Zhao, Andy Neal, Steve McGrath, Peter R Shewry and Susan Fairweather-Tait
Rothamsted Research Hertfordshire UK
10:40 - 11:00 Selenium accumulation and
speciation in biofortified hard wheat (Triticum durum L.) under
Mediterranean conditions: from grain to cooked pasta
María J. Poblaciones,
Sara M. Rodrigo, Oscar Santamaría, Santiago Lledó, Yi Chen and Steve P. McGrath
University of Extremadura, Badajoz, Spain
11:00 - 11:30 Coffee Break
selenium in various Allium sativum L.
cloneas and association with sulphur content
Horníčková Jana, Kučera Ladislav, Stavělíková Helena, Poucghová Vladuimíra and Velíšek Jan Crop Research Institute, Prague, Czech Republic
11:50 - 12:10 Anti-regurgitation (ar) infant formulas. expression of mineral transporters and storage proteins in caco-2 cells after in-vitro
gastrointestinal digestion
Carlos Alberto González-Bermúdez,
Miranda-Miranda L, Legay S, Corvisy A, Klein S, Frontela-Saseta C, Martínez-Graciá C and Evers D Department of Food Science and Nutrition, University of Murcia. Murcia, Spain
12:10 - 12:30 Lead enters plant cell by endocytosis Aneta Basińska,
Krzesłowska M., Mellerowicz E.J., Napieralska A., Rabęda I., Woźny A. and Adam Mickiewicz University, Poznań, Poland
12:30 - 14:00 Lunch
14:00 - 16:00 WORKING GROUP 3(WG3) Chair: Susan Fairweather-Tait Rapporteur: Sara Rodrigo
14:00 - 14:30 KEYNOTE:Algorithms for predicting iron absorption from plant foods
Manju B. Reddy and Seth M. Armah
Department of Food Science and Human Nutrition, Iowa State University, Ames, USA
14:30 - 15:00 KEYNOTE: Addressing the challenges of intrinsic labeling in iron and zinc stable isotope absorption studies with biofortified plant foods
Janet R. Hunt
International Atomic Energy Agency, Vienna, Austria
15:00 - 15:20 Iron-biofortified pearl millet provides additional bioavailable iron
compared to regular-iron millet but to a lesser extent than post-harvest iron-fortified millet
Colin Cercamondi,
Ines Egli, Evariste Mitchikpe, Erick Boy, Felicien Tossou, Christophe Zeder, Joseph Hounhouigan and Richard Hurrell Laboratory of Human Nutrition, ETH Zurich, Switzerland
12
15:20 - 15:40 Impact of polyphenols on iron bioavailability from potato after simulated gastro-intestinal digestion
Danièle Evers,
Lisa Miranda, Aude Corvisy, Hannah Deußer and Sylvain Legay
Centre de Recherche Public-Gabriel Lippmann, Luxembourg
15:40 - 16.00 General discussion and concluding remarks Poster awards
Bal Ram Singh and Peter Schröder
16:00 - 18:00 EXCURSION TO NOFIMA, Ås
18:00 - SOCIAL EVENTS - Dinner – Tapas in the Biotech building
THURSDAY JUNE 13TH DEPARTURE
P RESENTATION – K EYNOTE S PEAKERS
Professor ZED RENGEL, University of Western Australia, Perth, Australia BIOAVAILABILITY AND ROOT UPTAKE OF BENEFICIAL AND DETRIMENTAL TRACE ELEMENTS IN FOOD CROPS
Zed Rengel is Winthrop Professor in the School of Earth and Environment at the University of Western Australia. His research interests focus on nutrient uptake and ion toxicity in the soil-plant-water-microbe continuum, covering macro (phosphorus, potassium and magnesium) and micronutrients (zinc, copper and manganese) as well as toxic ions (aluminium, arsenic, cadmium, zinc and sodium). The approaches and techniques used range from fluorescence imaging microscopy and ion-specific microelectrodes to enzyme assays and radioisotope tracking. He also works on chemistry and biology of the rhizosphere soil and computer modelling of root growth and function.
Associate. Professor ELLIS HOFFLAND, Wageningen University, The Netherlands UNDERSTANDING ZINC BIOAVAILABILITY TO PLANTS
She is personal professor at the Department of Soil Quality of Wageningen, the Netherlands. Her field of expertise is soil fertility and soil-plant interactions and she is particularly interested in how plants improve soil fertility through
rhizosphere effects. She tries to integrate biology, chemistry and physics in her research.
WG2BIOLOGICAL FEATURES IN THE RELATIONSHIP BETWEEN PLANTS AND MINERALS
Dr. CATHERINE CURIE, CNRS Montpellier, France
CELLULAR IRON POOLS IN PLANTS: LOCALIZATION AND MOBILIZATION BY SPECIALIZED TRANSPORTERS
Catherine Curie obtained her PhD in 1992 in the University of Toulouse, France, during which she studied transcriptional regulation in Arabidopsis. From 1993 to 1996, she joined the lab of Sheila McCormick in Berkeley, California, to study pollen-specific regulatory pathways in tomato. In 1997, she went to the Biochemistry and Molecular Physiology lab in Montpellier, France, to work on iron homeostasis in plants in the group of Jean-François Briat. Since 2008, she has been leading an independent research group focusing on the mechanisms of transport of iron and manganese and their regulation. Right now, she is on sabbatical at the James Cook University of Townsville, Australia, to study iron/Mn in microalgae.
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Professor JIAN FENG MA, Okayama University, Kurashiki, Japan TRANSPORTERS INVOLVED IN CD ACCUMULATION IN RICE
Professor at Institute of Plant Science and Resources, Okayama University, Japan.
Major interests: Plant transporter identification of minerals including essential, beneficial and toxic minerals.
Published more than 160 papers in international journals including Nature, PNAS, Plant Cell, Plant Journal. etc.
Received JSPS Prizes and Japan Academy Medals in 2006, Awards of Japanese Society of Soil Science and Plant Nutrition in 2007, and Kihara Award in 2012.
Associate Editor of Functional Plant Biology and Section Editor of Plant and Soil.
WG3FOOD PROCESSING AND HUMAN NUTRITION
Dr. NAVREET BHULLAR, ETH Zurich, Switzerland
BIOTECHNOLOGICAL APPROACHES TO THE IRON BIOFORTIFICATION OF RICE
Dr. Bhullar is a research group leader at Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland since 2010. She obtained her PhD in 2008 from the Institute of Plant Biology at University of Zurich and then undertook
postdoctoral research at the same institute. Her research interests include crop biofortification, genetic diversity and mining for novel genes in the crop
genepools. She has published several research articles, review articles, book chapters and recently, co-edited a book entitled ‘Agricultural sustainability’. Dr.
Bhullar received distinctive appreciations to her research work, including the Gatersleben Research Award in 2010.
Professor BO LÖNNERDAHL, Distinguished Professor of Nutrition & Internal Medicine, Department of Nutrition & Program in International and Community Nutrition University of California, Davis, USA
IRON BIOAVAILABILITY IN HUMANS FROM PLANT FERRITIN
He received his master’s and doctorate degrees in biochemistry from University of Uppsala in Sweden, and has been professor at UCD since 1980.
Dr. Lönnerdal’s research has focused on bioactive components in breast milk, the effect of breast milk on the recipient infant and mechanisms underlying the protection against infection. His research includes the micronutrients iron and zinc; how they are secreted into milk and how they are utilized by the infant. He is also studying the bioavailability of iron and zinc from plant sources.
He has recieved many honours and awards for example:
Borden Award, American Institute of Nutrition, International Award for Modern Nutrition
2000 - Honorary Doctorate (Honoris causa) in Medicine, University of Uppsala, Sweden, and 2004 - Gabriel Bertrand Prize and Medal for research on trace
Dr. Lönnerdal has published more than 500 scientific articles, book chapters and books and is currently a member of the American Society of Nutrition (ASN), and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN).
Professor MANJU B.READDY, Iowa State University, Ames, USA ALGORITHMS FOR IRON PREDICTING IRON ABSORPTION FROM PLANT FOODS
Manju Reddy is a Professor at Iowa State University, Ames, Iowa, in the department of Food Science and Human Nutrition. She graduated from Texas A&M University, College Station, Texas with a PhD in Nutrition and worked at Kansa University Medical Center, Kansas City, Kansas, prior to joining Iowa State University. Her research focuses on strategies to improve iron bioavailability and iron status using in vitro models and humans. She also studies the iron excess related diseases, especially Parkinson’s and cardiovascular diseases and how nutritional factors prevent those diseases.
Dr. JANET HUNT, IAEA, Vienna, Austria
ADDRESSING THE CHALLENGES OF INTRINSIC LABELING IN IRON AND ZINC STABLE ISOTOPE ABSORPTION STUDIES WITH BIOFORTIFIED PLANT FOODS
Janet R. Hunt, Ph.D., R.D. is a nutrition specialist working for the International Atomic Energy Agency, an agency of the United Nations, in Vienna, Austria. She formerly worked as a research leader of the Mineral Utilization and
Bioavailability Project at the U.S. Department of Agriculture/Agricultural Research Service (USDA/ARS) Human Nutrition Research Center in Grand Forks, ND. Dr. Hunt received her Ph.D. in nutrition from the University of Minnesota.
She has been active in the American Society for Nutrition and the Academy of Nutrition and Dietetics. She also served on USA Institute of Medicine, National Academy of Sciences committees on Interpretation and Use of Dietary
Reference Intakes and on Mineral Requirements for Military Personnel. Her research interest is human iron and zinc requirements as influenced by dietary bioavailability, and she has published over 100 papers on these topics
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A BSTRACTS – K EYNOTE S PEAKERS
AVAILABILITY OF MICRONUTRIENTS AND UNDESIRABLE TRACE ELEMENTS IN THE SOIL-PLANT-MICROBE CONTINUUM
Zed Rengel
The University of Western Australia, Faculty of Science, Perth, Australia
Micronutrient availability in the rhizosphere is controlled by soil and plant properties, and interactions of roots with microorganisms and the surrounding soil. Plants exude a variety of organic compounds (carboxylate anions, phenolics, carbohydrates, amino acids, enzymes, etc.) and inorganic ions (protons, phosphate, etc.) to change chemistry and biology of the rhizosphere. Acidification of the rhizosphere soil increases mobilisation of micronutrients (eg.
for Zn, 100-fold increase in solubility for each unit of pH decrease) as well as potentially toxic trace elements, such as Cd and Al.
Decreased availability of micronutrients and undesirable trace elements is due to complexation with humic acids, lignin and other high-molecular-weight compounds. In contrast, increased availability may result from solubilisation and mobilisation by short-chain organic acids, amino acids and other low-molecular-weight organic compounds.
For diffusion-supplied micronutrients, the uptake rate is governed by the soil nutrient supply.
Fertilisation with micronutrients (more so in case of Zn than Fe) can be effective in increasing the concentration of micronutrients at the soil-root interface. In addition, micronutrient- efficient crops and genotypes can increase an available nutrient fraction and hence increase micronutrient uptake.
Our understanding of the physiological processes governing exudation and the soil-plant- microbe interactions in the rhizosphere is currently inadequate, especialy in terms of spatial and temporal variability in root exudation as well as the fate and effectiveness of organic and inorganic compounds in increasing availability of soil micronutrients and undesirable trace elements. The interactions between microorganism and plants at the soil-root interface are particularly important as well obscure.
Keywords: cadmium, iron, microorganisms, rhizosphere, zinc
18 K2
UNDERSTANDING ZINC BIOAVAILABILITY TO PLANTS Ellis Hoffland and Andreas Duffner
Wageningen University, Dept. Soil Quality, The Netherlands
Objectives Most soils contain sufficient amounts of zinc (Zn) to support crop growth for many years, but most of this Zn is not bioavailable. So understanding soil Zn bioavailability to plants is relevant to mineral-improved crop production for human health. I will give an overview of our work on processes in the soil-plant continuum that are relevant to Zn bioavailability.
Methods We performed field and pot experiments with wheat and other crop species on low Zn soils collected around the world. Root box experiments allowing for rhizosphere sampling were done to understand the effect of soil characteristics and root exudates on Zn bioavailability. Chemical speciation modeling was combined with plant bioassays.
Results Biogeochemical modelling showed that dissolved organic anions and pH are important determinants of Zn bioavailability. We showed that chemical conditions in the rhizosphere, which may deviate from the bulk soil, can impact Zn bioavailability, depending on the soil. Adsorption of Zn on the root surface was pH dependent and nonlinear and a useful proxy for bioavailable Zn.
Conclusions Rhizosphere conditions are relevant to understand mobilization of Zn from low Zn soils. Zinc speciation models develloped for Zn-contaminated soils appeard to be valid for low Zn soils, too, and a usefull tool to improve prediciton of Zn bioavailability to crops.
Keywords: bioavailability, root exudates, rhizosphere, soil, zinc
CELLULAR IRON POOLS: LOCALIZATION AND MOBILIZATION BY SPECIALIZED TRANSPORTERS
Hannetz Roschzttardtz, Fanchon Divol, Daniel Couch, Mathilde Séguéla, Louis Grillet, Geneviève Conéjéro, Stéphane Mari, Catherine Curie
Laboratoire de Biochimie et Physiologie Moléculaire Végétale, CNRS-INRA, Campus SupAgro, Montpellier, FRANCE
To acquire the essential heavy metal iron (Fe), plants have to overcome its low bioavailability in most soils by activating a now well-described high affinity machinery whose main actor in dicots is the Fe transporter IRT1. The next challenge to our community is to understand, once in the root, how Fe is distributed to plant organs and within cellular organelles. Parcels of knowledge are starting to emerge thanks to the recent development of elemental imaging techniques. In our lab, we have implemented a powerful histochemical staining method and used it both as a tool to study Fe movement within the plant, and to describe the Fe pools at the subcellular level within each plant organ. Doing so, and together with X-ray based elemental analyses, we identified a new unexpected abundant iron pool in the nucleolus of plant cells. By combining reverse genetics, Fe imaging and biochemistry, we have established the role of the efflux of citrate, a Fe ligand, in the distribution of iron to pollen grains, as well as characterized the role of two metal transporters, YSL4 and YSL6, in preventing Fe toxicity by mediating its efflux from the chloroplasts.
20 K4
TRANSPOTERS INVOLVED IN CD ACCUMULATION IN RICE Jian Feng Ma
Institute of Plant Science and Resources, Okayama University, Japan
Cadmium (Cd) in foods is a major health concern worldwide. Rice, an important staple food for nearly a half of the world’s population, is a major source of Cd intake. Therefore, it is necessary to limit Cd into the food chain from soil to reduce potential health risks to humans.
We have identified three transporters involved in Cd accumulation in rice. OsNramp5 is a major transporter for Cd uptake in the roots. It is localized in the distal side of both exodermal and endodermal cells. OsHMA3 is mainly expressed in the tonoplast of root cells.
It is responsible for sequestration of Cd into the vacuoles in the roots. On the other hand, OsHMA2 is a plasma membrane-localized transporter and localized in the pericycle of the root, which is responsible for translocation of Cd from the roots to the shoots. Knockout of OsNramp5 and OsHMA2 resulted in significant reduction of Cd accumulation in the grain, but also caused decreased yield. By contrast, overexpression of OsHMA3 selectively decreased accumulation of Cd in the grains without affecting the growth, while mutation of this gene resulted in increased Cd accumulation. Our results provide insight into the strategies for reducing Cd accumulation in rice grain.
Keyword: Accumulation, cadmium, rice, root, transporter
BIOTECHNOLOGICAL APPROACHES TO THE IRON BIOFORTIFICATION OF RICE Navreet K. Bhullar
Institute of Agricultural Sciences, Department of Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
Food security and healthy nutrition is of critical global importance. Around two billion people suffer from iron deficiency, particularly affecting women and children in developing countries. Monotonous diets based on staple cereals are frequently associated with such human micronutrient malnutrition. Cereal grains constituting most important basis of human food, are in fact a poor source of iron. Biofortification of cereal grains, such as rice, has therefore emerged as a promising strategy. However, the variability for most micronutrients is very low in the rice germplasm and this does not leave traditional breeding alone to be a valid option for rice biofortification in many circumstances. Complementing the breeding efforts, gene technology offers perspectives for efficiently improving iron content in rice grain. The biotechnological strategies used to date in order to improve rice for iron content, and the opportunities for future research will be presented.
Keywords: biofortification, iron, metal homeostasis, cereals
22 K6
IRON BIOAVAILABILITY IN HUMANS FROM PLANT FERRITIN Bo Lönnerdal
Department of Nutrition, University of California, Davis, USA
Meeting iron requirements is difficult for populations dependent upon plant foods, and iron deficiency is common. Beans contain ferritin in low concentrations, but it is possible to enhance this content by plant breeding or by inserting the gene for ferritin into plants, e.g., soybeans. Because each ferritin molecule can bind to thousands of iron atoms, this may be a sustainable means to increase the iron contents of plants. Before such efforts are launched, it is important to determine whether iron in ferritin is bioavailable. This was assessed in vitro by using human intestinal (Caco-2) cells and by using radiolabeled ferritin and whole-body counting in human subjects. Dietary factors affecting iron absorption had limited effect on iron uptake from intact ferritin by Caco-2 cells, suggesting that ferritin-bound iron is absorbed via a mechanism different from that of nonheme iron. In an in vitro digestion system, ferritin was shown to be relatively resistant to proteolytic enzymes. Binding of ferritin to Caco-2 cells was saturable, and kinetics for binding were characteristic of a receptor-mediated process. In human subjects, iron from soybean ferritin given in a meal was as well absorbed as iron from ferrous sulfate. In conclusion, iron is well absorbed from ferritin and may represent a means of biofortification of staple foods.
Keywords: ferritin, iron, iron absorption, iron bioavailability, plant ferritin
ALGORITHMS FOR PREDICTING IRON ABSORPTION FROM PLANT FOODS Manju B. Reddy and Seth M. Armah
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50014, USA Various algorithms have been developed taking into consideration the combined effect of dietary factors on nonheme iron absorption using single meal data. However, accuracy of predicting iron absorption from complete diets using those algorithms raised some concerns.
We developed a new algorithm based on complete diets using previous data where nonheme iron absorption was measured for 3 different dietary periods when each subject (n=53) consumed diets containing either high, low or typical amounts of the dietary factors (meat, vitamin C, calcium and tea) for 5-days. Our algorithm was validated with measured absorption reported in the literature. Compared to 16% in the single meal algorithm, only 3%
of the variation in absorption was explained by dietary factors in our algorithm. Ferritin and interpersonal variation explained a large proportion of the differences. Significant correlation was found when our algorithm was validated with single meal (R2=0.57; P<0.001) and complete diet (R2=0.84; P<0.0001) data. Using our algorithm with the NHANES data, total iron absorption from the US diet was found to be 15% which is lower than the current 18%. In conclusion, the algorithm based on complete diets will be useful for predicting nonheme iron absorption from the diets of different populations.
Keywords: absorption, algorithms, bioavailability, nonheme iron
24 K8
ADDRESSING THE CHALLENGES OF INTRINSIC LABELING IN IRON AND ZINC STABLE ISOTOPE ABSORPTION STUDIES WITH BIOFORTIFIED PLANT FOODS
Janet R. Hunt, Ph.D., R.D.
International Atomic Energy Agency, Vienna, Austria
Biofortification of foods with Fe and Zn requires enhanced mineral content plus demonstrated bioavailability (absorption and utilization) for humans. Bioavailability can be sensitively determined from retention of isotopes that label the respective mineral in the foods. Intrinsic labeling involves incorporation of the isotope into the food during growth under controlled (e.g., hydroponic) conditions emulating field conditions. Intrinsic labeling of Fe and Zn has often validated extrinsic labeling, the addition of isotope in the final stages of food preparation. One challenge of isotopic labeling is matching breeding or growing conditions that may result in Fe or Zn compounds that don’t fully interchange with other ingested nonheme Fe or Zn (heme Fe from animal foods is a primary example, but other examples may include ferritin iron). Another labeling challenge is to use tracer quantities that do not disturb absorptive efficiency or the ratios of mineral to components that affect bioavailability, such as phytate (which may also be affected by biofortification). Extrinsic labeling is economical and can be useful when added stable isotopes do not alter the amount or relative ratios of mineral to known enhancers and inhibitors. Substantial changes in the organic form of biofortified minerals may require tests using intrinsic labeling.
Keywords: extrinsic, intrinsic, iron, isotope, zinc
A BSTRACTS - O RAL P RESENTATION
TRANSFORMATION OF AS-SPECIES BETWEEN CULTIVATION MEDIUM AND PLANTS
Tommy Landberg1 and M. Greger1,2
1)Department of Ecology, Environment and Plant Sciences, Lilla Frescati,Stockholm University, SE-10691 Stockholm, Sweden email: [email protected]
2)Faculty of Applied Ecology and Agricultural Sciences, Hedmark University College, Blæstad, NO-2418 Elverum, Norway
Arsenic exists in several organic and inorganic forms. Environmental conditions such as redox potential and bacterial activity influence the As-speciation. The various As-species are differently available and toxic and their properties in cultivation medium and plants are necessary to understand to reduce the As risk in food. Therefore, the dynamics in As speciation during uptake in lettuce from cultivation medium was investigated.
Various cultivars of lettuce (Lactuca sativa L.) were cultivated either in soil or hydroponically. Treatment concentrations of As in soil were 2 - 140 mg kg-1 and 0 – 100 µM in hydroponics. Arsenic-species used were arsenite, arsenate, monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA). Plants were treated 3 hours - 7 weeks. Total As and As-species were analysed in plants and cultivation medium.
The results show that arsenic is transformed from arsenate, MMA and DMA to arsenite (which is the most toxic species). It is not due to selective uptake because treatment with either arsenate, MMA or DMA results in high arsenite in the plant. Arsenic translocated to the shoot have further higher propoportion of arsenite. The reduction from arsenate to arsenite in plants is known, while not the transformation from MMA and DMA to arsenite.
Keywords: Arsenic, food risk, plant, soil, speciation
26 A2
DECREASING OF CADMIUM IN WHEAT GRAIN DEPENDS ON THE FORM OF THE APPLIED ZINC
Zdenko Lončarić1, Maja Manojlović2, Brigita Popović1, Krunoslav Karalić1, Ranko Čabilovski2, Vladimir Ivazić1, Espen Govasmark3 and Bal Ram Singh3
1)Faculty of Agriculture in Osijek, Kralja Petra Svačića 1d, HR–31000 Osijek, Croatia
2)Faculty of Agriculture Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
3)Norwegian University of Life Sciences (UMB), Ås, Norway
The field experiment with three wheat cultivars was conducted on fertile calcareous soil with low zinc availability. The aim was to determine the effect of the applied zinc form on zinc, iron and cadmium in the grain. Therefore three following treatments were conducted: 1.
control, 2. Zn sulfate foliar, 3. Zn EDTA foliar. Fertilization treatments didn’t affected iron concentration in wheat organs, but significant differences were determined among cultivars (Divana>Srpanjka>Simonida) and organs (leaves>=glumes>spike axis>=grain>straw). The highest zinc concentration as average of all treatments was determined for cultivar Divana, and significantly lowers for Simonida and Srpanjka. As it was expected, the lowest zinc concentration in grain was in control treatment (24,4 mg kg-1), higher after Zn-EDTA (33,4) and highest after Zn-sulfate application (48,9). All cadmium concentrations were very low, and additionally affected by zinc application. Highest average cadmium was in straw, than leaves and spike axis and lowest in glumes and grains. Zn-sulfate significantly decreased cadmium concentration only in spike axis (85 vs. 128 µg kg-1), and not significantly in grain (53 vs. 62) and straw (91 vs. 110). The Zn-EDTA decreased cadmium in grain 66% compared to Zn-sulfate and 72% compared to control. Cadmium was also decreased in spike axis (22- 48%), but significantly increased in leaves (20-37%) and straw (20-57%).
Keywords: cadmium, foliar application, iron, zinc-EDTA, zinc-sulfate
AGRICULTURE ACTIVITIES AND THEIR IMPUT ON KEEPING THE ENTRY OF CADMIUM INTO THE FOOD CHAIN
Marta Pogrzeba1, Aleksandra Sas-Nowosielski1, Ewa Gucwa-Przepióra2, Eugeniusz Małkowski3 and Jacek Krzyżak1
1)Department of Environmental Biotechnology, Phytoremediation Team, Institute for Ecology of Industrial Areas (IETU), 6 Kossutha Street, 40-833 Katowice, Poland, mail:[email protected]
2)Department of Plant Systematic, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28 St, 40-032 Katowice, Poland
3)Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28 St, 40-032 Katowice, Poland
Barley in Poland is cultivated mostly for beer production, however about 4% is used for direct human consumption. Like other plants, when grown on contaminated soils it tends to accumulate heavy metals like cadmium. Cadmium accumulation and distribution within plants is strongly affected by the cultivar and the soil type. Recent data show that it can be also impacted by plant care activities.
Approximately 95% of plant species form mycorrhizal associations. It was found that AM hyphe are able to accumulate 10–20 times higher rates of Cd relative to the plant roots. Therefore AM fungi may be responsible for limiting Cd translocation to shoots via soil bioaugmentation. Cadmium uses zinc transport pathways to enter the plant, thus zinc application may be helpful in diminishing of Cd accumulation. Foliar application of zinc is increasingly used to elevate micro nutrient deficiencies of this element.
Barley roots colonization with AM fungi for different cultivars was investigated on clean soil and soil contaminated with cadmium and other heavy metals. AM attendance and Cd accumulation were revealed under the application of plant care and physiological treatments. Moreover reduction in cadmium uptake by barley after Zn foliar application was investigated. Physical and chemical soil properties were analyzed using ISO methods. The pot experiment with two barley cultivars was performed in natural conditions. Total cadmium concentration in contaminated soil was about 12.39 mg kg-1, while total Zn concentration, about 2174.5 mg kg-1. Cadmium bioavailable fractions were about 4.6% of total concentration, while for Zn about 2.2%.
Correlation between AM root colonization and Cd concentration in grains was assessed. The parameters of mycorrhizal development were evaluated microscopically based on frequency of mycorrhization of barley root fragments (F%), intensity of root cortex colonization (M%) and arbuscule abundance in the root system (A%). Cd concentration in grains was studied after application of two different Mono-Zn concentrations during the stages of ear formation and flowering.
The significant negative correlation was found between frequency of mycorrhization of root fragments (F%) and Cd concentration in grains. F% for particular barley cultivars decreased with increasing concentration of bioavailable Cd in soil, thus suggesting that accumulation of Cd in barley grains depends both, on plant physiological properties of cultivars and AM fungi. Application of Mono-Zn on leaves surface of some barley cultivars resulted in decrease of cadmium concentration in grain and straw. The results were related to the type of barley cultivar and kind of soil (clean, Cd-contaminated).
In conclusion our results highlight the necessity of reconsidering the usage of fungicydes, as this practice may actually open the gate for heavy metals to the human food chain and point to the possible utility of Zn foliar application.
Keywords: arbuscular mycorrhiza (AM), Zn foliar application, barley grains, Cd concentration, health risk
28 A4
SELENIUM CYCLE IN FIELD ECOSYSTEM
Mervi M. Seppänen1, Nashmin Ebrahimi1, Anthony Owusu-Sekyere1 and Helinä Hartikainen2
1)Department of Agricultural Sciences, University of Helsinki
2)Department of Food and Environmental Sciences, University of Helsinki
Selenium (Se), an essential micronutrient for humans and animals, is circulated to food chain via plants. In Finland, an annual Se fertilization is required in order to acquire adequate Se content in locally produced food and feed. Only 5 to 10 % of the applied Se is translocated to seeds and removed from fields whereas the fate of most Se in field ecosystem is unknown. We have conducted 2 to 3-year field and supplementary greenhouse experiments to study the Se cycle in field ecosystems where wheat, oil seed rape or forage grass-clover mixtures are cultivated. Se uptake and translocation to various plant parts were monitored during growing period and the interaction between Se and N fertilization was assessed. Up to 60 % of applied Se was taken up by plant but majority, 30 %, was left in plant depris, mainly in stems. Over 10 % is lost maybe due to volatilization or, as indicated by greenhouse experiments, metabolized by soil microbes. The annual variation between years was substantial; in a wet growing season 2012 Se uptake was significantly lower than in other studied years. There also seemed to be an interaction between Se uptake and plant N-status since foliar N fertilization at booting stage increased Se uptake.
Keywords: clover, forage grass, oil seed rape, translocation, uptake, wheat
EFFECTS OF DIFFUSION LIMITATIONS ON ZINC FLUXES INTO WHEAT ROOTS, DGT AND PLM DEVICES IN PRESENCE OF ORGANIC LIGANDS
Anja Gramlich1, Susan Tandy1, Emmanuel Frossard2, Jost Eikenberg3 and Rainer Schulin1
1)Institute of Terrestrial Ecosystems, ETH Zurich, Switzerland
2)Institute for Plant, Animal and Agroecosystems Sciences, ETH Zurich, Switzerland
3)Paul Scherrer Institute (PSI), Villigen, Switzerland
Organic ligands increase metal mobility in soils. The extent to which they enhance plant metal uptake depends besides other factors on diffusion limitations in the soil solution. In this study, we investigated the influence of diffusion layer thickness (δ) on zinc (Zn) uptake by wheat in the presence of EDTA, citrate and histidine from hydroponic solutions with equal free Zn concentrations by measuring 65Zn uptake from stirred, non-stirred and agar-containing nutrient solutions. Analogous experiments were performed using permeation liquid membranes (PLM) and ‘diffusive gradients in thin films’ (DGT) probes instead of plants in order to identify the potential role of diffusion limitation in root Zn uptake. In treatments with EDTA or ligand-free Zn solution an increase in δ reduced the fluxes of Zn into roots, PLM and DGT probes to a similar extent, suggesting that they were limited by diffusion. In presence of citrate the flux of Zn into the roots was similar as in presence of EDTA for the same total and free Zn concentrations under stirred conditions, but did not decrease when δ was increased by not stirring the solution and by adding agar. This indicates that diffusion and complex dissociation were both rate limiting. This explanation is supported by the fact that similar δ effects were found in PLM influxes where uptake of negatively charged complexes can be excluded. Zn influx into roots was much higher in the histidine treatments than in all other ligand treatments and also not affected by increasing δ. PLM measurements suggested that dissociation kinetics for Zn-histidine were fast and could explain the higher uptake rate by the plants partially. However, as Zn root uptake in presence of histidine was very high, it is probable that the neutral or positive Zn-histidine complexes contributed directly to metal uptake.
Keywords: diffusion limitations, Zn bioavailability, Zn-citrate, Zn-histidine, wheat
30 A6
EFFECT OF DIFFERENT CROPPING SYSTEMS ON SOIL ZINC CONTENT AND AVAILABILITY
Thilo Dürr-Auster1, R. Schulin2, P. Mäder3, J. Mayer4, M. Mazzoncini5 and E. Frossard1
1)Institute of Agricultural Sciences, Group of Plant Nutrition, ETH Zurich, Eschikon 33, Lindau (ZH), 8315, Switzerland ([email protected])
2)Institute of Terrestrial Ecosystems, Group of Soil Protection, ETH Zurich, Universitätstrasse 16, Zuerich, 8092, Switzerland ([email protected])
3)Research Institute of Organic Agriculture FIBL, Group of Soil Science, Ackerstrasse, Frick, 5070, Switzerland ([email protected])
4)Agroscope Reckenholz-Tänikon Research Station ART, Reckenholzstrasse 191, Zürich, 8046, Switzerland ([email protected])
5)Department of Agronomy, University of Pisa, Via S. Michele degli Scalzi 2, Pisa, 56124, Italy ([email protected])
Zn deficiency in crops can be linked to two major causes: i) low Zn content of the soil and ii) low plant-available Zn in the soil. The present project is investigating the impact of fertilization strategies, with emphasis on organic fertilizers, on the Zn transfer from the soil to the plant. On the one hand organic fertilizer can be considered as an important Zn source, and on the other they can affect the exchangeable Zn pools of the soil.
In the present part of the project, the effect of different fertilization strategies on the soil Zn status are being compared by analysing soils from long-term field trials for their total-Zn (XRF) and available-Zn (DTPA-extractable zinc). Three sites have been chosen: i) the “DOK”
which was set up in 1978 (Therwil near Basel, Switzerland), the “ZOFE” which was established in 1949 (Zurich-Reckenholz, Switzerland) and the “MASCOT” field trial set up in 2001 (Pisa, Italy). The applied organic fertilizers are specific to each field trial and are covering the most common organic fertilizers used in agriculture: manure, compost, sewage sludge, dry manure pellets, dry bovine blood but also mineral fertilizer, all added in agronomically relevant quantities. Archive-samples will allow us to analyse the evolution of the total Zn-status in the treatments of the two oldest long-term field trials.
Preliminary results suggest that there is a significant increase of plant available and total Zn in the organic treatments compared to the control with mineral or no fertilization. Furthermore, these results indicate that changes of the zinc status only happen in the upper layer of the soil.
Further analysis is currently in progress. Data evaluation will consider the long term Zn input- output budgets and soil properties of the different treatments. These results will be available at the conference.
Keywords: cropping system, long-term field trials organic fertilizer, zinc
EFFECT OF INTERCROPPING SYSTEMS AND FERTILIZERS ON MAIZE AND SOYBEAN GRAIN COMPOSITION
Dragicevic Vesna1, Oljaca Snezana2, Dolijanovic Zeljko2, Stojiljkovic Milovan3, Spasojevic Igor1 and Nisavic Marija2
1)Maize Research Institute “Zemun Polje”, Slobodana Bajica 1, 11185 Zemun Polje-Belgrade, Serbia
2)University of Belgrade, Faculty of Agriculture, Nemanjina 6, 11080 Zemun-Belgrade, Serbia
3)Vinca Institute of Nuclear Sciences, PO Box 522, 11001 Belgrade, Serbia
Ecological cropping systems include combination of different crops at the same field and application of organic fertilizers, what could enable better utilization of space and nutrients, with minimal inputs. Trial was conducted during 2011 and 2012, with varieties of red grain maize and black grain soybean, grown as: single crop (SC), alternating rows of both crops (AR) and alternating strips (3 rows of each species - AS). Fertilization regimes included incorporation of: urea, Ofert (organic fertilizer) and Uniker (microbiological fertilizer). After harvest, grain yield, mass of 1000 grains, content of Mg, Fe, Zn, P, including ratio between phytic and inorganic P (Pphy/Pi), as well as antioxidants: phenolics and glutathione were determined in grains.
There were minor variations in grain yield between treatments, while Uniker and Ofert increased mass of 1000 grains. In SC cropping in maize, Uniker increased Zn, while Ofert increased Fe content. Irrespective to several times higher contents of Mg, Fe, Zn and P in soybean grain, compared to maize, Ofert increased Mg and Zn content in soybean in AS cropping. Moreover, Ofert increased accumulation of antioxidants in both crops, mainly in AR treatment, while the both organic fertilizers decreased Pphy/Pi ratio, underlining their positive effect on nutritive quality of produced crops.
Keywords: antioxidants, cropping systems, fertilization, grain, mineral composition
32 A8
IMPROVED UPTAKE OF MINERAL NUTRIENTS BY INTERCROPPED FORAGE MAIZE AND FABA BEANS
Eva Stoltz
The Rural Economy and Agricultural Society, Hushållningssällskapet/HS Konsult AB, Box 271, S-701 45 Örebro, Sweden email: [email protected]
Intercropping may have advantages such as higher yield, reduced presence of plant diseases and increased uptake of mineral nutrients. The aim was to investigate the effect of intercropping on uptake of micronutrients and sulphur in organically produced faba bean (Vicia faba L.) and maize (Zea mays L.). Three field experiments were performed with faba bean and maize cultivated in pure stands or intercropped. Disease severity index (DSI) of leaf spots in faba beans was determined. At harvest, shoot samples were taken and analysed for mineral nutrients. Intercropping significantly increased the concentrations of Cu (from 4.1 to 4.6 mg/kg) and Zn (from 17.2 to 20.8 mg/kg) in maize and B (from 15.3 to 17.8 mg/kg) and S (from 0.14 to 0.15 % of DM) in faba bean compared with sole crops. Leaf spot DSI was significantly lower in intercropped faba beans (mean 25) than in sole faba bean (mean 45). A significant negative relationship between Cu concentration in faba bean and DSI of leaf spots was found, and the shoot Cu concentration tended to increase by intercropping. Intercropped maize and faba bean improved forage quality by increased concentration of mineral nutrients and reduced DSI of leaf spots in faba beans.
Keywords: faba bean, intercrop, leaf spots, maize, mineral nutrients
ANALYSIS OF A ZINC-SENSOR FUNCTION IN THE ARABIDOPSIS BZIP19/23 TRANSCRIPTION FACTORS
Ana G.L. Assunção1,Mark G.M. Aarts2, Pai Pedas3, Daniel P. Persson3, Søren Husted3 and Jan K. Schjoerring3
1)Plant Evolution Group, Research Center in Biodiversity and Genetic Resources, University of Porto, R. Padre Armando Quintas, 4485-661 Vairão, Vila do Conde, Portugal
2)Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
3)Section for Plant and Soil Sciences, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
As a plant micronutrient, zinc is of major interest in agronomy and for human and cattle nutrition. Zinc deficient soils are widespread all over the world and the risk of inadequate diet and zinc malnutrition is estimated to affect one third of the global human population, i.e.
around 2 billion people. Developing countries, where people depend on cereal-rich diets for sustenance, are the most affected. Improvement of crop efficiency in zinc deficient environments, and bio-fortification to alleviate human nutrition are plant-based solutions as source of micronutrients.
An incomplete understanding of zinc homeostasis mechanisms in plants is however a limitation. Recently the first transcription factors regulating zinc homeostasis in Arabidopsis were identified. The AtbZIP19 and AtbZIP23 were shown to be essential for the adaptation to zinc deficiency. Transcript profiling revealed only a small set of genes, to be induced in wild- type plants in response to zinc deficiency, but not in the bzip19bzip23 double mutant line, which shows a zinc deficiency hypersensitive phenotype1. Anchored to this knowledge, it is now possible to elucidate, upstream to these transcription factors, the molecular mechanisms that allow plants to sense zinc deficiency and adapt to this stress. We hypothesised that the characteristic His/Cys-rich domains in the bZIP19 and bZIP23 transcription factors2 are involved in the direct sensing of zinc.
In order to test this hypothesis, we are analysing metal-binding properties of bZIP19/bZIP23 by SEC-ICP-MS (SizeExclusion Chromatography/Inductively Coupled Plasma Mass Spectrometry). Additionally, amino acid substitutions on bZIP19/23, targeting the His/Cys- motif2, are being prepared for similar metal-binding analysis. The results obtained so far are discussed.
Keywords: Micronutrients, Plant nutrition, Transcription factors, Zinc deficiency, SEC-ICP-MS References:
[1] Assunção, A. G. L. et al. (2010) Arabidopsis thaliana transcription factors bZIP19 and bZIP23 regulate the adaptation to zinc deficiency. Proceedings of the National Academy of Sciences of the United States of America 107, 10296–301.
[2] Jakoby, M. et al. (2002) bZIP transcription factors in Arabidopsis. Trends in plant science 7, 106–11.
34 A10
NATURAL VARIATION OF ARABIDOPSIS THALIANA HAPMAP POPULATION REVEALS CANDIDATE GENES CONTROLLING ZINC DEFICIENCY TOLERANCE Ana Carolina Atala Lombelo1, Charles Neris Moreir a1, David E. Salt2 and Mark G.M. Aarts1
1)Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands
2)Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
The low availability of Zn in calcareous and high pH soils result on severe growth and yield reduction for plants. Zn deficiency affects 30% of the world soils, including many agricultural lands in Australia, South-east Asia, Central and South America, Africa, India, Spain, USA, among others (Alloway 2004). In nature, some plants are able to overcome this nutrition limited gift by uptaking and utilizing Zn more efficiently. In this study we used natural variation to investigate which genes are involved in Zn deficiency tolerance or sensitiveness of Arabidopsis thaliana. The effect of Zn deficiency in the phenotype of different A. thaliana accessions was clear with plants showing chlorosis, stunted growth and necrotic spots.
Several candidate genes were identified by Genome Wide Association (GWAS) mapping.
Traits analysed were, shoot dry biomass, root total length, shoot chlorosis, Zn deficiency tolerance index (%), and difference between treatments (Zn Control – Zn Deficiency). Shoot and root complete elemental profile is being analysed in collaboration with the group of Professor David E. Salt at the University of Aberdeen with an STSM funding from the Cost Action office. Manhattan plots showed many peaks of small and moderate significance suggesting that the traits studied are polygenic (Figure 1). An average of 5 QTLs (peaks) per trait distributed over the 5 chromosomes was observed. Candidate genes were selected based on the LOD score, gene function and co-expression with other genes related to Zn homeostasis.
Keywords: biofortification, genome wide association mapping, nutrient homeostasis
CAPTURING UNPRECEDENTED NATURAL DIVERSITY IN PLANT METAL ACCUMULATION: A COMPREHENSIVE SURVEY OF EUROPEAN ARABIDOPSIS
HALLERI POPULATIONS
Stephan Höreth1, Ricardo Stein2, Ute Krämer2 and Stephan Clemens1
1Department of Plant Physiology, University of Bayreuth, Germany
2Department of Plant Physiology, University of Bochum, Germany
As part of a project aiming at the genome-wide molecular analysis of variation in A. halleri metal hyperaccumulation we conducted a large survey covering the natural range of A. halleri in Europe. We have analyzed in total over 2000 field-collected leaf and rhizosphere soil samples of A. halleri individuals from 195 populations. Herbivory was scored to test the elemental defense hypothesis. About 800 individuals were transferred to the lab for phenotyping under controlled, uniform conditions. The field data for 20 elements reveal associations between soil factors and elemental profiles as well as between metal acquisition pathways. We found, for instance, an extreme extent of variation and regional patterns in Cd hyperaccumulation. The initial phenotyping under controlled conditions confirmed these results, suggesting recent evolution of the Cd hyperaccumulation trait. Moreover, not only variation in Cd and Zn accumulation was observed, but also substantial variation for other micronutrients such as Fe and Mn to a degree that has rarely been documented to date. Thus, through the use of next-generation sequencing technologies, this collection of 800 genotypes will enable the molecular dissection of many aspects of plant microelement nutrition in addition to the evolution of Zn/Cd hyperaccumulation.
Keywords: Cd accumulation, field studies, genome-wide analysis, natural variation, Zn accumulation
