Interplay of chelating and reducing root exudates in plant iron acquisition

植物铁获取过程中螯合和减少根系分泌物的相互作用

基本信息

批准号：
291474925
负责人：
Dr. Günther Weber
金额：
--
依托单位：
Institut für Bodenforschung (IBF)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/291474925?language=en
关键词：
Interplay chelating reducing root exudates

项目摘要

Due to the low iron (Fe) solubility in most soils, plants have evolved Fe acquisition strategies that are mainly based on the chelation and reduction of ferric Fe. While graminaceous plants release mugineic acid-type siderophores from their roots for ferric Fe chelation, non-graminaceous plants rely primarily on the reduction of ferric Fe which is compromised at high pH. Recently, a new class of coumarin-type siderophores has been identified in root exudates that mediate ferric Fe chelation, however, due to their high chemical versatility their mode of action in the rhizosphere is still unclear. Therefore, the present project aims at i) identifying new exudate compounds with novel or specific Fe-related functions, in particular regarding the chelation and/or reduction of Fe(III) and to characterize modifications and chemical interactions of these compounds on their way from the release by root cells through the root apoplast into the rhizosphere soil and back; ii) examining synergisms among individual root exudates involved in Fe mobilization by from Fe-bearing phases in the soil; iii) identifying and quantifying the contribution and interplay of chemical and biological processes involved in Fe acquisition via plant-exuded reductants and iron ligands in the rhizosphere. To address a set of 8 defined hypotheses, two German and two Austrian labs from molecular plant nutrition, analytical chemistry, rhizosphere ecology and biogeochemistry will collect root exudates from hydroponic and rhizosphere systems, conduct metal-chelate speciation by advanced mass spectrometry-coupled techniques, assess Fe chelation and redox chemistry of root exudates from wild-type and mutant plants and employ thermodynamic and kinetic modelling approaches. This proposal promises to chemically identify key players in root exudates and to describe their mode of action as chelators, reductants or redox shuttles for an improved Fe nutrition in plants.

由于大多数土壤中铁（FE）的溶解度较低，因此植物的进化采购策略主要基于铁铁的螯合和减少。谷物植物从其根部释放出米甘酸型铁载体以进行铁螯合，但非碎屑植物主要依赖于在高pH值下受到损害的铁铁的还原。最近，在介导铁螯合的根渗出液中发现了一类新的香豆素型铁载体，但是由于它们的高化学多功能性，其在根际中的作用方式仍不清楚。因此，本项目的目的是i）识别具有新型或特定与FE相关功能的新的渗出剂，特别是关于Fe（III）的螯合和/或减少，并表征这些化合物的修饰和化学相互作用，从根细胞通过根部通过根细胞释放到根部的Rhizosphere土壤和背部的方法中； ii）检查各个根部渗出量的协同作用，从土壤中的含水相动员中涉及Fe动员； iii）识别和量化通过植物估算的还原剂和铁配体在根际中涉及的化学和生物过程的贡献和相互作用。 To address a set of 8 defined hypotheses, two German and two Austrian labs from molecular plant nutrition, analytical chemistry, rhizosphere ecology and biogeochemistry will collect root exudates from hydroponic and rhizosphere systems, conduct metal-chelate speciation by advanced mass spectrometry-coupled techniques, assess Fe chelation and redox chemistry of root exudates from wild-type and mutant plants and employ热力学和动力学建模方法。该提案有望在根部渗出液中的化学识别主要参与者，并将其作用方式描述为螯合剂，还原剂或氧化还原班车，以改善植物中的Fe营养。