Drought and salt stress are two major environmental constraints that limit the productivity of agriculture crops worldwide. WRKY transcription factors are the plantspecific transcription factors that regulate several developmental events and stress responses in plants. The WRKY domain is defined by a 60-amino acid conserved sequence named WRKYGQK at N-terminal and a Zinc Finger-like motif at the Cterminal. WRKY genes are known to respond several stresses which may act as negative or positive regulators. The function of most of the WRKY transcription factors from non-model plants remains poorly understood. This investigation shows the expression levels of eight WRKY transcription factor genes from horsegram plant under drought and salt stress conditions. The increase in mRNA transcript levels of WRKY transcription factor genes was found to be high in drought stressed plants compared to salt-stressed plants. The levels of MDA which indicates the lipid peroxidation were less in drought stress. More ROS is produced in salt stress conditions compared to drought. The results show that the expression of WRKY transcription factors in drought stress conditions is reducing the adverse effect of stress on plants. These results also suggest that, during abiotic stress conditions such as drought and salt stress, WRKY transcription factors are regulated at the transcription level.

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Foxtail millet (Setaria italica L.) is a drought-tolerant millet crop of arid and semi-arid regions. Aldo-keto reductases (AKRs) are significant part of plant defence mechanism, having an ability to confer multiple stress tolerance. In this study, AKR1 gene expression was studied in roots and leaves of foxtail millet subjected to different regimes of PEG-and NaCl-stress for seven days. The quantitative Real-time PCR expression analysis in both root and leaves showed upregulation of AKR1 gene during PEG and salt stress. A close correlation exits between expression of AKR1 gene and the rate of lipid peroxidation along with the retardation of growth. Tissue-specific differences were found in the AKR1 gene expression to the stress intensities studied. The reduction in root and shoot growth under both stress conditions were dependent on stress severity. The level of lipid peroxidation as indicated by MDA formation was significantly increased in roots and leaves along with increased stress levels. Finally, these findings support the early responsive nature of AKR1 gene and seem to be associated at least in part with its ability to contribute in antioxidant defence related pathways which could provide a better protection against oxidative stress under stress conditions.

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