花生铁运输基因进化的新功能及其在玉米/花生间作体系中的生态优势作用

Peanut/maize intercropping is a sustainable and effective agroecosystem that evidently enhances the iron nutrition of peanuts in calcareous soils. Although significant progress has been made in recent years in Fe-acquisition mechanisms in Strategy I and Strategy II plants, a lack of knowledge persists on how Fe behaves in intercropped systems of Strategy I and Strategy II plants and how Strategy I plants (peanut) use Fe(III)-PS from graminaceous plants at the molecular level. So far, the molecular mechanism involved in this process has not been elucidated. In our recent study, we unravel the novel evolutionary functions of iron transporter of AhYSL1 and AhFRDL1 in peanut. The objective of the present study will apply transgenic hairy root of peanut and RNAi to identify and characterize of 5 Yellow Stripe1-Like (AhYSLs) genes in peanuts for Fe(III)-PS uptake, and illustrate AhFRDL1 as a citrate transporter which could not only improve iron translocation but also increase Al resistance. Moreover, the study will investigate how peanut plants utilize the Fe(III)-PS, dissolved by the nearby maize, might be directly absorbed by AhYSLs in the nearby peanuts. Further our study will also investigate how intercropping of maize and peanut regulate AhFRDL1 expression and show Al resistance in response to Al stress. Finally, Our study will illustrate the novel evolutionary function of AhYSLs gene in Fe(III)-PS transport and AhFRDL1 gene in iron translocation and increase Al resistance and their molecular ecological significance of intercropping of maize and peanut at molecular, physiological and ecological level. Our study would provide some evidence for improvement resources efficiency and high crop production in intercropping systems.

以华北平原生产中应用面积较大且间作优势明显的玉米/花生间作能够改善花生铁营养的生态优势现象为主题，前期课题最新的研究发现花生铁运输基因AhYSL1和 AhFRDL1表现出新的进化功能，以此为依据和切入点利用花生毛根遗传转化和RNAi相结合以及基因原位表达从分子和生理功能证明AhYSLs家族中的5个基因是否在花生植株内能够直接吸收植物铁载体所螯合的铁；柠檬酸运输载体AhFRDL1在花生植株内兼备促进铁的运输和抗铝胁迫的生物学机制，进一步证明玉米/花生间作体系中花生AhYSLs基因如何利用玉米所产生的麦根酸铁的分子生态功能，研究间作对AhFRDL1表达调控及其在间作中促进铁的吸收和抗铝的调控作用，从分子、生理和生态层面阐明花生在长期的进化过程中铁运输基因产生新功能的调控机制和间作体系中提高资源利用的分子生态优势作用，为通过科学合理的间作措施提高资源利用和高产高效提供重要的理论依据和技术支撑。

以华北平原生产中应用面积较大且间作优势明显的玉米/花生间作能够改善花生铁营养的生态优势现象为主题, 经过系统研究确立了玉米活化的Fe(III)–DMA可能被邻近的花生根表皮细胞AhYSL1基因直接吸收利用, 这对玉米花生间作改善花生铁营养提供了重要的和直接的分子证据；同时，也对机理I植物也存在能够吸收Fe(III)–DMA的基因的理论奠定了重要的基础。首次克隆获得并证明了没有测序的花生中铁的吸收运输基因AhDMT1和AhIRT1的生物学功能，克隆获得花生AhFRDL1基因具有促进铁的吸收和抗铝毒分子和生理功能，这是作物中首个发现的对铁的吸收和运输具有重要的作用, 同时对花生抗铝毒胁迫具有重要的生理功能的基因，表明该基因对植物适应缺铁胁和铝毒迫进化过程中具有重要的分子生态作用，土壤条件下从转录组和蛋白组的水平阐明了玉米/花生间作这一生产调控措施促进花生根系对根际铁的吸收和向地上部转运的分子生理功能与改善花生铁营养的机制和生态适应规律。这对于从分子、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改善根际生态环境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