title: AhDMT1, a Fe(2+) transporter, is involved in improving iron nutrition and N2 fixation in nodules of peanut intercropped with maize in calcareous soils.
abstract: Peanut (Arachis hypogaea L.) is an important legume providing edible proteins and N2 fixation. However, iron deficiency severely reduces peanut growth in calcareous soils. The maize/peanut intercropping effectively improves iron nutrition and N2 fixation of peanut under pot and field conditions on calcareous soils. However, little was known of how intercropping regulates iron transporters in peanut. We identified AhDMT1 as a Fe(2+) transporter which was highly expressed in mature nodules with stronger N2 fixation capacity. Promoter expression analysis indicated that AhDMT1 was localized in the vascular tissues of both roots and nodules in peanut. Short-term Fe-deficiency temporarily induced an AhDmt1 expression in mature nodules in contrast to roots. However, analysis of the correlation between the complex regulation pattern of AhDmt1 expression and iron nutrition status indicated that sufficient iron supply for long term was a prerequisite for keeping AhDmt1 at a high expression level in both, peanut roots and mature nodules. The AhDmt1 expression in peanut intercropped with maize under 3 years greenhouse experiments was similar to that of peanut supplied with sufficient iron in laboratory experiments. Thus, the positive interspecific effect of intercropping may supply sufficient iron to enhance the expression of AhDmt1 in peanut roots and mature nodules to improve the iron nutrition and N2 fixation in nodules. This study may also serve as a paradigm in which functionally important genes and their ecological significance in intercropping were characterized using a candidate gene approach.
authors: Key Laboratory of Plant-Soil Interactions, MOE, Centre for Resource, Environment and Food Surity, College of Resources and Environmental Sciences, China Agricultural University, No. 2, Yuanmingyuan West Road, Beijing, 100193, China.
authors: Hongyun
authors: H
authors: Shen
authors: Hongchun
authors: H
authors: Xiong
authors: Xiaotong
authors: X
authors: Guo
authors: Pengfei
authors: P
authors: Wang
authors: Penggen
authors: P
authors: Duan
authors: Lixia
authors: L
authors: Zhang
authors: Fusuo
authors: F
authors: Zhang
authors: Yuanmei
authors: Y
authors: Zuo
mesh_terms: D000383:Agriculture; D000595:Amino Acid Sequence; D010367:Arachis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005816:Genetic Complementation Test; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation / Q000187:drug effects / Q000235:genetics; D009591:Nitrogenase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053204:Root Nodules, Plant / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D016415:Sequence Alignment; D012987:Soil; D013997:Time Factors; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism*
chemical_list: D026901:Membrane Transport Proteins; D010940:Plant Proteins; D012987:Soil; D007501:Iron; D009591:Nitrogenase