OsNAC2 encoding a NAC transcription factor that affects plant height through mediating the gibberellic acid pathway in rice. (April 2015)

• Record Type: Journal Article
• Authors: Chen, Xu; Lu, Songchong; Wang, Yaofeng; Zhang, Xuan; Lv, Bo; Luo, Liqiong; Xi, Dandan; Shen, Jiabin; Ma, Hong; Ming, Feng
• Is Part Of: Plant journal. Volume 82:Number 2(2015:Apr.)
• Page Start: 302
• Page End: 314
• Publication Date: 2015-04
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12819
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12819-abs-0001"> <title>Summary</title> <p>Plant height and flowering time are key agronomic traits affecting yield in rice (<italic>Oryza sativa</italic>). In this study, we investigated the functions in rice growth and development of <italic>OsNAC2</italic>, encoding a NAC transcription factor in rice. Transgenic plants that constitutively expressed <italic>OsNAC2</italic> had shorter internodes, shorter spikelets, and were more insensitive to gibberellic acid (GA<sub>3</sub>). In addition, the levels of GAs decreased in <italic>OsNAC2</italic> overexpression plants, compared with the wild‐type. Moreover, flowering was delayed for approximately 5 days in transgenic lines. The transcription of <italic>Hd3a</italic>, a flowering‐time related gene, was suppressed in transgenic lines. In addition, transgenic Arabidopsis plants expressing <italic>OsNAC2</italic> were also more insensitive to GA<sub>3</sub>. The expression levels of GA biosynthetic genes <italic>OsKO2</italic> and <italic>OsKAO</italic> were repressed. The expression of <italic>OsSLRL</italic>, encoding a repressor in the GA signal pathway, and <italic>OsEATB</italic>, 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 <italic>OsEATB</italic> and <italic>OsKO2</italic>. Taken together, we proposed that <italic>OsNAC2</italic> is a negative regulator of the plant height and flowering time, which acts by directly regulating key genes of the GA pathway in rice.</p> </abstract>