Development of abiotic stress tolerance via bZIP-type transcription factor LIP19 in common wheat.
Cereal lip19 genes encoding bZIP-type transcription factors are assumed to play a regulatory role in gene expression during the cold acclimation process. However, no direct evidence shows an association of LIP19-type bZIPs with stress tolerance or activation of stress-responsive Cor/Lea genes. To understand the molecular basis of development of abiotic stress tolerance through the LIP19 transcription factor, a wheat lip19 homologue, Wlip19, was isolated and characterized. Wlip19 expression was activated by low temperature in seedlings and was higher in a freezing-tolerant cultivar than in a freezing-sensitive one. Wlip19 also responded to drought and exogenous ABA treatment. Wlip19-expressing transgenic tobacco showed a significant increase in abiotic stress tolerance, especially freezing tolerance. Expression of a GUS reporter gene under the control of promoter sequences of four wheat Cor/Lea genes, Wdhn13, Wrab17, Wrab18, and Wrab19, was enhanced by Wlip19 expression in wheat callus and tobacco plants. These results indicate that WLIP19 acts as a transcriptional regulator of Cor/Lea genes in the development of abiotic stress tolerance. Moreover, direct protein-protein interaction between WLIP19 and a wheat OBF1 homologue TaOBF1, another bZIP-type transcription factor, was observed, suggesting that this interaction is conserved in cereals.
Kobayashi
Fuminori
F
Laboratory of Plant Genetics, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
Maeta
Eri
E
Terashima
Akihiro
A
Kawaura
Kanako
K
Ogihara
Yasunari
Y
Takumi
Shigeo
S
D000040:Abscisic Acid / Q000494:pharmacology; D000064:Acclimatization; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D005615:Freezing; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018525:Germination / Q000187:drug effects; D009994:Osmolar Concentration; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism*
D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D014157:Transcription Factors; C076976:OBF1 protein, Zea mays; D000040:Abscisic Acid