WRKY Transcription Factors: Molecular Regulation and Stress Responses in Plants

Abstract

Plants in their natural habitat have to face multiple stresses simultaneously. Evolutionary adaptation of developmental, physiological, and biochemical parameters give advantage over a single window of stress but not multiple. On the other hand transcription factors like WRKY can regulate diverse responses through a complicated network of genes. So molecular orchestration of WRKYs in plant may provide the most anticipated outcome of simultaneous multiple responses. Activation or repression through W-box and W-box like sequences is regulated at transcriptional, translational, and domain level. Because of the tight regulation involved in specific recognition and binding of WRKYs to downstream promoters, they have become promising candidate for crop improvement. Epigenetic, retrograde and proteasome mediated regulation enable WRKYs to attain the dynamic cellular homeostatic reprograming. Overexpression of several WRKYs face the paradox of having several beneficial affects but with some unwanted traits. These overexpression-associated undesirable phenotypes need to be identified and removed for proper growth, development and yeild. Taken together, we have highlighted the diverse regulation and multiple stress response of WRKYs in plants along with the future prospects in this field of research.

OsWRKY80-OsWRKY4 Module as a Positive Regulatory Circuit in Rice Resistance Against Rhizoctonia solani

“…Global gene expression profiling has revealed a large number of WRKY genes that are rapidly induced or repressed upon pathogen infection, suggesting that these WRKY genes may contribute to the regulation of rice response to pathogen infection (Ryu et al 2006; Bagnaresi et al 2012; Wei et al 2013). Moreover, some rice WRKY factors have been characterized to be involved in plant defense responses (Pandey and Somssich 2009; Jimmy and Babu 2015; Phukan et al 2016). However, the roles of WRKY transcription factors in rice denfense against sheath blight is quite limited.…”

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“…Apart from this they are also involved in various crosstalk, which regulate response to stress and development [19]. Numerous reports suggest that they are also regulated by a plethora of plant enzymes in various elucidated and unelucidated mechanisms [20].…”

STOREKEEPER RELATED1/G-Element Binding Protein (STKR1) Interacts with Protein Kinase SnRK1

“…Members of these plant-specific transcription factor families have been implicated in biotic and abiotic stress responses as well as in the regulation of developmental programs such as senescence (Nuruzzaman et al, 2013;Bernsdorff et al, 2016;Kim et al, 2016;Phukan et al, 2016). The expression of a subset of differentially expressed WRKY and NAC genes was analyzed by qRT-PCR in an independent set of plants (Supplemental Fig.…”

“…Among the DEGs identified in 35S-STKR1 plants were a number of genes encoding members of the WRKY and NAC families of transcription factors. These protein families are particularly rich in senescence-regulated transcription factors in many plant species (Kim et al, 2016;Phukan et al, 2016), and their members have been described as positive as well as negative regulators of plant senescence, although a distinct regulatory function with respect to senescence regulation has only been reported for some WRKY and NAC transcription factors so far. Among the WRKY transcription factors significantly induced in 35S-STKR1 plants are WRKY70 and WRKY54, which were recently shown to act as negative regulators of leaf senescence in Arabidopsis (Besseau et al, 2012).…”