Raviraj Banakar1,2, Ana Alvarez Fernandez3, Changfu Zhu1, Javier Abadia3, Teresa Capell1, Paul Christou4,5. 1. Department of Plant Production and Forestry Sciences, School of Agrifood and Forestry Science and Engineering (ETSEA), University of Lleida-Agrotecnio Center, Avenida Alcalde Rovira 191, 25198, Lleida, Catalunya, Spain. 2. Centre for Precision Plant Genomics and Centre for Genome Engineering, Department of Plant and Microbial Genomics, College of Biological Sciences, University of Minnesota, St. Paul, MN, 55108, USA. 3. Department of Plant Nutrition, Aula Dei Experimental Station, Spanish Council for Scientific Research (CSIC), P.O. BOX 13034, 50080, Saragossa, Spain. 4. Department of Plant Production and Forestry Sciences, School of Agrifood and Forestry Science and Engineering (ETSEA), University of Lleida-Agrotecnio Center, Avenida Alcalde Rovira 191, 25198, Lleida, Catalunya, Spain. christou@pvcf.udl.es. 5. ICREA, Catalan Institute for Research and Advanced Studies, Passeig Lluís Companys 23, 08010, Barcelona, Spain. christou@pvcf.udl.es.
Abstract
MAIN CONCLUSION: The ratio of nicotianamine to deoxymugenic acid controls tissue-specific metal homeostasis in rice and regulates metal delivery to the endosperm. The metal-chelating phytosiderophores nicotianamine (NA) and 2'deoxymugenic acid (DMA) are significant factors for the control of metal homeostasis in graminaceous plants. These compounds are thought to influence metal homeostasis, but their individual roles and the effect of altering the NA:DMA ratio are unknown. We purposely generated rice lines with high and low NA:DMA ratios (HND and LND lines, respectively). The HND lines accumulated more iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu) in the endosperm through the mobilization of Fe, Zn and Mn from the seed husk to the endosperm. In contrast, Fe, Zn and Mn were mobilized to the husk in the LND lines, whereas Cu accumulated in the endosperm. Different groups of metals are, therefore, taken up, transported and sequestered in vegetative tissues in the HND and LND lines to achieve this metal distribution pattern in the seeds. We found that different sets of endogenous metal homeostasis genes were modulated in the HND and LND lines to achieve differences in metal homeostasis. Our findings demonstrate that the NA:DMA ratio is a key factor regulating metal homeostasis in graminaceous plants. These findings can help formulate refined strategies to improve nutrient composition and nutrient use efficiency in crop plants.
MAIN CONCLUSION: The ratio of nicotianamine to deoxymugenic acid controls tissue-specific metal homeostasis in rice and regulates metal delivery to the endosperm. The metal-chelating phytosiderophores nicotianamine (NA) and 2'deoxymugenic acid (DMA) are significant factors for the control of metal homeostasis in graminaceous plants. These compounds are thought to influence metal homeostasis, but their individual roles and the effect of altering the NA:DMA ratio are unknown. We purposely generated rice lines with high and low NA:DMA ratios (HND and LND lines, respectively). The HND lines accumulated more iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu) in the endosperm through the mobilization of Fe, Zn and Mn from the seed husk to the endosperm. In contrast, Fe, Zn and Mn were mobilized to the husk in the LND lines, whereas Cu accumulated in the endosperm. Different groups of metals are, therefore, taken up, transported and sequestered in vegetative tissues in the HND and LND lines to achieve this metal distribution pattern in the seeds. We found that different sets of endogenous metal homeostasis genes were modulated in the HND and LND lines to achieve differences in metal homeostasis. Our findings demonstrate that the NA:DMA ratio is a key factor regulating metal homeostasis in graminaceous plants. These findings can help formulate refined strategies to improve nutrient composition and nutrient use efficiency in crop plants.
Entities:
Keywords:
Metal homeostasis; NA:DMA ratio; Oryza sativa L.; Phytosiderophores; Transcriptome
Authors: Catherine Curie; Gaëlle Cassin; Daniel Couch; Fanchon Divol; Kyoko Higuchi; Marie Le Jean; Julie Misson; Adam Schikora; Pierre Czernic; Stéphane Mari Journal: Ann Bot Date: 2008-10-31 Impact factor: 4.357