Regulation of multiple aquaporin genes in Arabidopsis by a pair of recently duplicated DREB transcription factors

• Published in: Planta Vol. 234; no. 3; pp. 429 - 444
• Main Authors: Rae, Liina, Lao, Nga T., Kavanagh, Tony A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer 01-09-2011; Springer-Verlag; Springer Nature B.V
• Subjects: Adaptation, Physiological - genetics; Agriculture; Aquaporins; Aquaporins - genetics; Aquaporins - metabolism; Arabidopsis - genetics; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Biomedical and Life Sciences; Cold-Shock Response - genetics; Crop improvement; Dehydration; Dehydration - genetics; Drought; Ecology; Environmental regulations; Forestry; Fundamental and applied biological sciences. Psychology; Gels; Gene Expression Regulation, Plant; Genes; Genes, Plant; Heat tolerance; Heat-Shock Response - genetics; Homeostasis - genetics; Life Sciences; Messenger RNA; Original Article; Osmotic Pressure - physiology; Plant Sciences; Plants; Plants, Genetically Modified; RNA; Salinity; Transcription factors; Transcription Factors - genetics; Transcriptional Activation; Transcriptional regulatory elements; Water - metabolism; Transcriptional profiling; Gene expression; Transcription factor; Abiotic stress; Aquaporin; Multiple; Transcription; Arabidopsis; Plant biology; Arabidopsis thaliana; Gene; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Experimental plant
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-011-1414-z

Identifying the transcription factors that mediate responses to abiotic stress is of fundamental importance in plant biology, not least because of their potential utility in crop improvement. The recently duplicated genes RAP2.4B and RAP2.4 encode transcription factors belonging to the abiotic stress-associated DREB A-6 clade in Arabidopsis thaliana. Both proteins localise exclusively to nuclei and show similar DRE-element-binding characteristics. Expression analysis of stressed and non-stressed plants revealed partially overlapping expression patterns. Both genes were highly expressed in stems and roots and were differentially induced in response to cold, dehydration and osmotic stress. RAP2.4B, however, was uniquely expressed at a high level in dry seeds and was induced by heat stress, while RAP2.4 was uniquely induced at a high level by salt stress. Microarray-based transcriptional profiling of double knockout and overexpression lines revealed altered expression of genes associated with adaptation to drought stress. Most strikingly, six aquaporin genes, five of which are members of a recently identified co-expression network, were downregulated in the double knockout line and correspondingly upregulated in the overexpression line, suggesting that these DREBs play a role in the regulation of water homeostasis.