title: Strigolactones are involved in phosphate- and nitrate-deficiency-induced root development and auxin transport in rice.
abstract: Strigolactones (SLs) or their derivatives have recently been defined as novel phytohormones that regulate root development. However, it remains unclear whether SLs mediate root growth in response to phosphorus (P) and nitrogen (N) deficiency. In this study, the responses of root development in rice (Oryza sativa L.) to different levels of phosphate and nitrate supply were investigated using wild type (WT) and mutants defective in SL synthesis (d10 and d27) or insensitive to SL (d3). Reduced concentration of either phosphate or nitrate led to increased seminal root length and decreased lateral root density in WT. Limitation of either P or N stimulated SL production and enhanced expression of D10, D17, and D27 and suppressed expression of D3 and D14 in WT roots. Mutation of D10, D27, or D3 caused loss of sensitivity of root response to P and N deficiency. Application of the SL analogue GR24 restored seminal root length and lateral root density in WT and d10 and d27 mutants but not in the d3 mutant, suggesting that SLs were induced by nutrient-limiting conditions and led to changes in rice root growth via D3. Moreover, P or N deficiency or GR24 application reduced the transport of radiolabelled indole-3-acetic acid and the activity of DR5::GUS auxin reporter in WT and d10 and d27 mutants. These findings highlight the role of SLs in regulating rice root development under phosphate and nitrate limitation. The mechanisms underlying this regulatory role involve D3 and modulation of auxin transport from shoots to roots.
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Huwei
authors.initials: H
authors.lastname: Sun
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Tao
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shangjun
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shuangjie
authors.initials: S
authors.lastname: Huang
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: Weed Science Center, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.affiliation: Weed Science Center, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China ylzhang@njau.edu.cn.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006575:Heterocyclic Compounds, 3-Ring / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D007783:Lactones / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009566:Nitrates / Q000378:metabolism* / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010710:Phosphates / Q000172:deficiency* / Q000494:pharmacology; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development*; D036226:Seedlings / Q000187:drug effects; D014316:Tritium / Q000378:metabolism
chemical_list: D003470:Culture Media; C000591191:GR24 strigolactone; D006575:Heterocyclic Compounds, 3-Ring; D007210:Indoleacetic Acids; D007783:Lactones; D009566:Nitrates; D010710:Phosphates; D014316:Tritium
keywords: Auxin; nitrate; phosphate; rice; root; strigolactone.