Molecular Characterization of Three GIBBERELLIN-INSENSITIVE DWARF2 Homologous Genes in Common Wheat.
F-box protein is a core component of the ubiquitin E3 ligase SCF complex and is involved in the gibberellin (GA) signaling pathway. To elucidate the molecular mechanism of GA signaling in wheat, three homologous GIBBERELLIN-INSENSITIVE DWARF2 genes, TaGID2s, were isolated from the Chinese Spring wheat variety. A subcellular localization assay in onion epidermal cells and Arabidopsis mesophyll protoplasts showed that TaGID2s are localized in the nuclei. The expression profiles using quantitative real-time polymerase chain reaction showed that TaGID2s were downregulated by GA3. The interaction between TaGID2s and TSK1 (homologous to ASK1) in yeast indicated that TaGID2s might function as a component of an E3 ubiquitin-ligase SCF complex. Yeast two-hybrid assays showed that a GA-independent interaction occurred between three TaGID2s and RHT-A1a, RHT-B1a, and RHT-D1a. Furthermore, TaGID2s interact with most RHT-1s, such as RHT-B1h, RHT-B1i, RHT-D1e, RHT-D1f, etc., but cannot interact with RHT-B1b or RHT-B1e, which have a stop codon in the DELLA motif, resulting in a lack of a GRAS domain. In addition, RHT-B1k has a frame-shift mutation in the VHIID motif leading to loss of the LHRII motif in the GRAS domain and RHT-D1h has a missense mutation in the LHRII motif. These results indicate that TaGID2s, novel positive regulators of the GA response, recognize RHT-1s in the LHRII motif resulting in poly-ubiquitination and degradation of the DELLA protein.
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
XueYuan
X
Lou
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Xin
X
Li
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
AiXia
A
Li
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
MingYu
M
Pu
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Muhammad
M
Shoaib
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
DongCheng
D
Liu
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
JiaZhu
J
Sun
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.|The Collaborative Innovation Center for Grain crops in Henan, Henan Agricultural University, Zhengzhou, 450002, China.
AiMin
A
Zhang
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
WenLong
W
Yang
D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D032461:Chromosomes, Plant / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005875:Gibberellins / Q000378:metabolism*; D012275:Oryza / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014908:Triticum / Q000235:genetics*; D020798:Two-Hybrid System Techniques
D018076:DNA, Complementary; D005875:Gibberellins; D010940:Plant Proteins