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

Abstract

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.

WITHDRAWN: Physiological and biochemical characterization of tomato transgenic lines overexpressing Arabidopsis thaliana cold responsive-element binding factor 3 (AtCBF3) gene under chilling stress

“…It has been documented that the capability to cold acclimatize is associated with definite signal transduction pathways ensuring in the commencement of numerous cold-regulated (COR) genes that develop tolerance in plants (Castonguay et al, 2013). C-repeat binding factors (CBF/DREB) have been reported in previous studies to induce the expression of a group of genes related to increased stress tolerance (Wisniewski et al, 2011;Yang et al, 2011;Rae et al, 2011). The subfamily DREB can be divided into further six small classes termed as A-1 to A-6 (Liu et al, 2007).…”

Medicago truncatula ERN Transcription Factors: Regulatory Interplay with NSP1/NSP2 GRAS Factors and Expression Dynamics throughout Rhizobial Infection

“…This suggests that ERN1 and ERN2 possess both specific and overlapping expression profiles during rhizobial infection. A number of other closely related TFs also display specific and overlapping expression patterns during different developmental processes (AP2 TFs [Chandler et al, 2007;Rae et al, 2011] and NAC TFs [Mitsuda and Ohme-Takagi, 2008]). Such finetuned regulation is generally associated with both redundant and specific functions of the respective TFs.…”

The Hevea brasiliensis AP2/ERF superfamily: from ethylene signalling to latex harvesting and physiological disease response

“…It has been shown that the abundance of RAP2.4 protein was regulated by a BR-C, ttk and bab/Pox virus Zinc finger (BTP/POZ-MATH) or briefly known as BPM protein family (Weber & Hellmann, 2009). In addition, it is suggested that this gene plays a role in the regulation of water homeostasis (Rae et al, 2011). The HbERF-Ib7 gene is a GEM in response to latex harvesting stress but it has no known ortholog in Arabidopsis.…”