【摘要】 根据近十多年来相关研究成果讨论了土壤微生物在植物根系吸收铁中可能的作用机理。这种机理可能包括缺铁植物根系分泌小分子有机化合物,如酚类和黄素类等化合物,这些化合物作为抑菌剂和(或)作为微生物生长的碳源物质来影响根际(Rhizosphere)微生物的群落结构,并在植物根际诱导形成特异性微生物种群,此类特异性微生物转而通过分泌高铁载体(Siderophore),增加土壤中铁的生物有效性,从而提高了根系对铁的吸收。此外,与植物根系共生的一些微生物也会改善植物的铁营养,这种作用可能包括:根瘤菌(Rhizobium)的结瘤作用,增强植物耐缺铁的生理响应;根系感染的菌根真菌通过增加植物根系的养分吸收面积和分泌对铁具有螯合作用的物质来改善植物的铁营养。本文在讨论这种可能的微生物作用机制的基础上,指出今后的研究方向和有待解决的问题。更多还原

【Abstract】 Iron deficiency in plants is a worldwide agricultural problem. It has been proved that soil microorganisms have a beneficial effect on the iron acquisition of some plants, but the underlying mechanism is still unclear. Based on last ten years’ research results, possible mechanism on how the microorganisms favor plant iron acquisition was discussed in this review. Iron-deficiency-induced root exudates, such as phenolic and flavin compounds, acting as inhibitors and carbon sources, affected the architecture of microorganisms in the rhizosphere and induced a formation of a specified microorganism community. Those specified microorganisms in turn benefited the plant iron acquisition through the secretion of siderophore which could improve the bioavailability of iron in soil. In addition, the symbiosis between some microorganisms and plants could also improve plant iron nutrient status. The underlying processes may involve: the formation of rhizobium nodulation enhanced plant iron-deficient response, and mycorrhizal fungi infected root which improved the iron nutrient status through enlarging absorption area and excreting the materials which chelated iron of plant.更多还原