title: The rice YABBY4 gene regulates plant growth and development through modulating the gibberellin pathway.
abstract: YABBY genes encode seed plant-specific transcription factors that play pivotal roles in diverse aspects of leaf, shoot, and flower development. Members of the YABBY gene family are primarily expressed in lateral organs in a polar manner and function to specify abaxial cell fate in dicotyledons, but this polar expression is not conserved in monocotyledons. The function of YABBY genes is therefore not well understood in monocotyledons. Here we show that overexpression of the rice (Oryza sativa L.) YABBY4 gene (OsYABBY4) leads to a semi-dwarf phenotype, abnormal development in the uppermost internode, an increased number of floral organs, and insensitivity to gibberellin (GA) treatment. We report on an important role for OsYABBY4 in negative control of the expression of a GA biosynthetic gene by binding to the promoter region of the gibberellin 20-oxidase 2 gene (GA20ox2), which is a direct target of SLR1 (the sole DELLA protein negatively controlling GA responses in rice). OsYABBY4 also suppresses the expression level of SLR1 and interacts with SLR1 protein. The interaction inhibits GA-dependent degradation of SLR1 and therefore leads to GA insensitivity. These data together suggest that OsYABBY4 serves as a DNA-binding intermediate protein for SLR1 and is associated with the GA signaling pathway regulating gene expression during plant growth and development.
authors: University of Chinese Academy of Sciences, Yuquan Road 19, Shijingshan District, Beijing 100049, China Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors: Chao
authors: C
authors: Yang
authors: University of Chinese Academy of Sciences, Yuquan Road 19, Shijingshan District, Beijing 100049, China Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors: Yamei
authors: Y
authors: Ma
authors: Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China jxli@scbg.ac.cn.
authors: Jianxiong
authors: J
authors: Li
mesh_terms: D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology*; D005875:Gibberellins / Q000378:metabolism / Q000502:physiology*; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D005875:Gibberellins
keywords: 
  GA20ox2
  ; DELLA protein; SLR1; YABBY4.; gibberellin; rice