Soybean GmbZIP44, GmbZIP62 and GmbZIP78 genes function as negative regulator of ABA signaling and confer salt and freezing tolerance in transgenic Arabidopsis.
From soybean plant, 131 bZIP genes were identified and named as GmbZIPs. The GmbZIPs can be classified into ten groups and more than one third of these GmbZIPs are responsive to at least one of the four treatments including ABA, salt, drought and cold stresses. Previous studies have shown that group A bZIP proteins are involved in ABA and stress signaling. We now chose four non-group A genes to study their features. The four proteins GmbZIP44, GmbZIP46, GmbZIP62 and GmbZIP78 belong to the group S, I, C and G, respectively, and can bind to GLM (GTGAGTCAT), ABRE (CCACGTGG) and PB-like (TGAAAA) elements with differential affinity in both the yeast one-hybrid assay and in vitro gel-shift analysis. GmbZIP46 can form homodimer or heterodimer with GmbZIP62 or GmMYB76. Transgenic Arabidopsis plants overexpressing the GmbZIP44, GmbZIP62 or GmbZIP78 showed reduced ABA sensitivity. However, all the transgenic plants were more tolerant to salt and freezing stresses when compared with the Col plants. The GmbZIP44, GmbZIP62 and GmbZIP78 may function in ABA signaling through upregulation of ABI1 and ABI2 and play roles in stress tolerance through regulation of various stress-responsive genes. These results indicate that GmbZIP44, GmbZIP62 and GmbZIP78 are negative regulators of ABA signaling and function in salt and freezing tolerance.
Liao
Yong
Y
Plant Gene Research Center, National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, China.
Zou
Hong-Feng
HF
Wei
Wei
W
Hao
Yu-Jun
YJ
Tian
Ai-Guo
AG
Huang
Jian
J
Liu
Yun-Feng
YF
Zhang
Jin-Song
JS
Chen
Shou-Yi
SY
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D003001:Cloning, Molecular; D003080:Cold Temperature; D019281:Dimerization; D015870:Gene Expression; D005810:Multigene Family; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D054712:Salinity; D015398:Signal Transduction; D013025:Glycine max / Q000235:genetics*; D013379:Substrate Specificity; D015533:Transcriptional Activation; D014867:Water / Q000378:metabolism
D050976:Basic-Leucine Zipper Transcription Factors; D014867:Water; D000040:Abscisic Acid