title: A strigolactone signal is required for adventitious root formation in rice.
abstract: OBJECTIVE
  Strigolactones (SLs) and their derivatives are plant hormones that have recently been identified as regulating root development. This study examines whether SLs play a role in mediating production of adventious roots (ARs) in rice (Oryza sativa), and also investigates possible interactions between SLs and auxin.
  
  
  METHODS
  Wild-type (WT), SL-deficient (d10) and SL-insensitive (d3) rice mutants were used to investigate AR development in an auxin-distribution experiment that considered DR5::GUS activity, [(3)H] indole-3-acetic acid (IAA) transport, and associated expression of auxin transporter genes. The effects of exogenous application of GR24 (a synthetic SL analogue), NAA (α-naphthylacetic acid, exogenous auxin) and NPA (N-1-naphthylphalamic acid, a polar auxin transport inhibitor) on rice AR development in seedlings were investigated.
  
  
  RESULTS
  The rice d mutants with impaired SL biosynthesis and signalling exhibited reduced AR production compared with the WT. Application of GR24 increased the number of ARs and average AR number per tiller in d10, but not in d3. These results indicate that rice AR production is positively regulated by SLs. Higher endogenous IAA concentration, stronger expression of DR5::GUS and higher [(3)H] IAA activity were found in the d mutants. Exogenous GR24 application decreased the expression of DR5::GUS, probably indicating that SLs modulate AR formation by inhibiting polar auxin transport. The WT and the d10 and d3 mutants had similar expression of DR5::GUS regardless of exogenous application of NAA or NPA; however, AR number was greater in the WT than in the d mutants.
  
  
  CONCLUSIONS
  The results suggest that AR formation is positively regulated by SLs via the D3 response pathway. The positive effect of NAA application and the opposite effect of NPA application on AR number of WT plants also suggests the importance of auxin for AR formation, but the interaction between auxin and SLs is complex.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Huwei
authors.initials: H
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Tao
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Shuangjie
authors.initials: S
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Tianning
authors.initials: T
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Yunqi
authors.initials: Y
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China and Center for Bioscience Research & Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan ylzhang@njau.edu.cn.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D001692:Biological Transport; D007783:Lactones / Q000378:metabolism*; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism
chemical_list: D007783:Lactones; D010937:Plant Growth Regulators
keywords: Adventitious root formation; IAA; Oryza sativa; SL; auxin; plant hormone; rice; root growth; strigolactone