玉米/花生间作改善花生铁营养的生理及分子机制  

Physiological and molecular mechanisms of improved iron nutrition of peanut intercropping with maize

作　　者：邱巍 王男麒 代晶 王天琪 左元梅[1] Wei Qiu;Nanqi Wang;Jing Dai;Tianqi Wang;Yuanmei Zuo(Centre for Resource,Environment and Food Security,College o f Resource and Environmental,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学资源与环境学院资源环境与粮食安全中心,北京100193

出　　处：《科学通报》2019年第11期1129-1136,共8页Chinese Science Bulletin

基　　金：国家自然科学基金(31872183);国家重点研发计划(2017YFD0202102;2016YFD0200405;2016YFE0101100)资助

摘　　要：间作是农田生态系统资源高效利用和生产可持续发展的重要种植模式之一.华北平原广泛实行的玉米/花生间作明显减轻花生的缺铁黄化症状并能提高植株铁含量和籽粒产量,近十多年系统和深入的研究揭示了这一具有传统特色的中国农业生产体系背后蕴含的科学规律.从生理生化水平而言,根际互作的生态优势能够明显地影响间作花生根系对铁的吸收和体内运输,并在分子水平调节各过程中所对应的基因表达及其功能.位于花生根表皮细胞调控吸收麦根酸铁复合物的AhYSL1基因,能够专一性地吸收转运麦根酸铁,表明机理Ⅰ植物花生可能直接吸收利用间作机理Ⅱ植物玉米所产生的麦根酸铁.在石灰性土壤,将两种不同铁吸收机理的作物间作既能提高两种作物对环境胁迫的抗逆性,又能改善机理Ⅰ植物的铁营养,利用间作根际效应提高作物矿质元素富集也是一种潜在的"生物强化"途径,对改善人体微量营养元素具有重要意义.玉米/花生根际互作的机理研究与生产实践紧密结合,从分子、生理和生态层面理解利用不同植物生物学特性的互惠作用为改善根际生态环境、活化和提高作物铁营养和资源高效利用的效应与机制提供重要的理论和技术依据.Intercropping is one of the most important farming practices for efficient use of farmland ecosystems and sustainable yield productions. Peanut intercropped with maize could significantly reduce peanut chlorosis symptom and increase the plant iron(Fe) content and crop yield in the North China Plain. The physiological and molecular mechanisms behind this phenomenon have been extensively studied for decades.Peanut and maize have evolved two distinct mechanisms in response to Fe deficiency, known as "the Strategy Ⅰ" and "the Strategy Ⅱ", respectively. The Strategy Ⅰ plants take up Fe2+ through soil acidification and Fe3+ reduction, while the Strategy Ⅱ plants acquire Fe via secreting mugineic acid family phytosiderophores(MAs) to dissolve insoluble ferric Fe and to form absorbable Fe(Ⅲ)–MAs complexes in the rhizosphere. At the molecular level, key genes involved in Fe acquisition have been well characterized. In the Strategy Ⅰ plants, peanut ferric reductase oxidase2(AhFRO2) and iron regulated transporter1(AhIRT1) are responsible for the reduction of Fe(Ⅲ)-chelate to Fe(Ⅱ) and the uptake of Fe(Ⅱ),respectively. In the Strategy Ⅱ plants, MAs are synthesized from methionine and secreted by mugineic acid transporter1(MA1). The secreted MAs solubilize Fe in the rhizosphere and the resultant Fe(Ⅲ)-MAs complex is then absorbed by the yellow stripe1(YS1) transporter in maize. As a result, the Strategy Ⅱ maize is more effective at mobilizing precipitated Fe,less affected by high p H and bicarbonate levels, and having a much stronger ability to resist Fe-limitation stress in calcareous soils compared with Strategy Ⅰ peanuts.However, the Fe-limitation stress in peanuts could be alleviated when intercropping with maize. At physiological and biochemical levels, the ecological advantages of rhizosphere interaction is to significantly enhance the absorption and transport of Fe by intercropped peanut roots and to validate the functions of genes involved. In particular, it has been demonstrated that the A

关 键 词：玉米 花生 间作 根际互作 铁营养改善 资源高效 

分 类 号：S565.2[农业科学—作物学] S513