title: Soybean Fe-S cluster biosynthesis regulated by external iron or phosphate fluctuation.
abstract: Iron and phosphorus are essential for soybean nodulation. Our results suggested that the deficiency of Fe or P impairs nodulation by affecting the assembly of functional iron-sulfur cluster via different mechanisms. Iron (Fe) and phosphorus (P) are important mineral nutrients for soybean and are indispensable for nodulation. However, it remains elusive how the pathways of Fe metabolism respond to the fluctuation of external Fe or P. Iron is required for the iron-sulfur (Fe-S) cluster assembly in higher plant. Here, we investigated the expression pattern of Fe-S cluster biosynthesis genes in the nodulated soybean. Soybean genome encodes 42 putative Fe-S cluster biosynthesis genes, which were expressed differently in shoots and roots, suggesting of physiological relevance. Nodules initiated from roots of soybean after rhizobia inoculation. In comparison with that in shoots, iron concentration was three times higher in nodules. The Fe-S cluster biosynthesis genes were activated and several Fe-S protein activities were increased in nodules, indicating that a more effective Fe-S cluster biosynthesis is accompanied by nodulation. Fe-S cluster biosynthesis genes were massively repressed and some Fe-S protein activities were decreased in nodules by Fe deficiency, leading to tiny nodules. Notably, P deficiency induced a similar Fe-deficiency response in nodules, i.e, certain Fe-S enzyme activity loss and tiny nodules. However, distinct from Fe-deficient nodules, higher iron concentration was accumulated and the Fe-S cluster biosynthesis genes were not suppressed in the P-deficiency-treated nodules. Taken together, our results showed that both Fe deficiency and P deficiency impair nodulation, but they affect the assembly of Fe-S cluster maybe via different mechanisms. The data also suggested that Fe-S cluster biosynthesis likely links Fe metabolism and P metabolism in root and nodule cells of soybean.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Qin
authors.forename: Meihuan
authors.initials: M
authors.lastname: Wang
authors.forename: Liyu
authors.initials: L
authors.lastname: Chen
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Liang
authors.forename: Zhigeng
authors.initials: Z
authors.lastname: Wu
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Lin
authors.forename: Jia
authors.initials: J
authors.lastname: Zuo
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Feng
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Liao
authors.forename: Hong
authors.initials: H
authors.lastname: Ye
mesh_terms: D018506:Gene Expression Regulation, Plant; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D000090463:Iron Deficiencies; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family; D009572:Nitrite Reductases / Q000235:genetics / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D013025:Glycine max / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
chemical_list: D007506:Iron-Sulfur Proteins; D010710:Phosphates; D010758:Phosphorus; D007501:Iron; D009572:Nitrite Reductases