title: Ethylene is involved in root phosphorus remobilization in rice (Oryza sativa) by regulating cell-wall pectin and enhancing phosphate translocation to shoots.
abstract: Background and aims Plants are able to grow under phosphorus (P)-deficient conditions by coordinating Pi acquisition, translocation from roots to shoots and remobilization within the plant. Previous reports have demonstrated that cell-wall pectin contributes greatly to rice cell-wall Pi re-utilization under P-deficient conditions, but whether other factors such as ethylene also affect the pectin-remobilizing capacity remains unclear. Methods Two rice cultivars, 'Nipponbare' (Nip) and 'Kasalath' (Kas) were cultured in the +P (complete nutrient solution), -P (withdrawing P from the complete nutrient solution), +P+ACC (1-amino-cyclopropane-1-carboxylic acid, an ethylene precursor, adding 1 μm ACC to the complete nutrient solution) and -P+ACC (adding 1 μm ACC to -P nutrient solution) nutrient solutions for 7 d. Key Results After 7 d -P treatment, there was clearly more soluble P in Nip root and shoot, accompanied by additional production of ethylene in Nip root compared with Kas. Under P-deficient conditions, addition of ACC significantly increased the cell-wall pectin content and decreased cell-wall retained P, and thus more soluble P was released to the root and translocated to the shoot, which was mediated by the expression of the P deficiency-responsive gene OsPT2, which also strongly induced by ACC treatment under both P-sufficient and P-deficient conditions. Conclusions Ethylene positively regulates pectin content and expression of OsPT2, which ultimately makes more P available by facilitating the solubilization of P fixed in the cell wall and its translocation to the shoot.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China and.
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China and.
authors.forename: Chun Quan
authors.initials: CQ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China and.
authors.forename: Xu Sheng
authors.initials: XS
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China and.
authors.forename: Ren Fang
authors.initials: RF
authors.lastname: Shen
keywords: Rice; cell-wall polysaccharides; ethylene; gene expression; pectin; phosphorus; remobilization; transport