title: OsNAC2 encoding a NAC transcription factor that affects plant height through mediating the gibberellic acid pathway in rice.
abstract: Plant height and flowering time are key agronomic traits affecting yield in rice (Oryza sativa). In this study, we investigated the functions in rice growth and development of OsNAC2, encoding a NAC transcription factor in rice. Transgenic plants that constitutively expressed OsNAC2 had shorter internodes, shorter spikelets, and were more insensitive to gibberellic acid (GA(3)). In addition, the levels of GAs decreased in OsNAC2 overexpression plants, compared with the wild-type. Moreover, flowering was delayed for approximately 5 days in transgenic lines. The transcription of Hd3a, a flowering-time related gene, was suppressed in transgenic lines. In addition, transgenic Arabidopsis plants expressing OsNAC2 were also more insensitive to GA(3). The expression levels of GA biosynthetic genes OsKO2 and OsKAO were repressed. The expression of OsSLRL, encoding a repressor in the GA signal pathway, and OsEATB, which encodes a repressor of GA biosynthesis, were both enhanced. Western blotting indicated that DELLA also accumulated at the protein level. Dual-luciferase reporter analyses, yeast one-hybrid assays and ChIP-qPCR suggested that OsNAC2 directly interacted with the promoter of OsEATB and OsKO2. Taken together, we proposed that OsNAC2 is a negative regulator of the plant height and flowering time, which acts by directly regulating key genes of the GA pathway in rice.
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Songchong
authors.initials: S
authors.lastname: Lu
authors.forename: Yaofeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Lv
authors.forename: Liqiong
authors.initials: L
authors.lastname: Luo
authors.forename: Dandan
authors.initials: D
authors.lastname: Xi
authors.forename: Jiabin
authors.initials: J
authors.lastname: Shen
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.forename: Feng
authors.initials: F
authors.lastname: Ming
mesh_terms: D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D005875:Gibberellins; D010940:Plant Proteins; D014157:Transcription Factors; C007842:gibberellic acid
keywords: GA biosynthesis and response; OsNAC2; flowering delayed; plant height; rice