Expression of gmhk07 gene in response to aba and drought treatments of drought tolerant (dt51) and susceptive (mtd720) soybean varieties

Abscisic acid (ABA) is an important phytohormone involving in plant adaptation to abiotic stress. Gene expression study in response to ABA helps to identify the candidate genes for improvement of crop tolerance genetic engineering. In this study, the regulatory role of GmHK07 was investigated in two soybean varieties having contrasting phenotypes, including the drought-tolerant (DT51) and -sensitive (MTD720) phenotypes, under ABA and drought stress treatment. The qRT-PCR results of 12-day-old plants subjected to 100 µM ABA treatment showed that GmHK07 was repressed significantly in root and shoot tissues of MTD720. Besides, the expression of this gene in MTD720 shoots was 158-folds and 85-folds higher than those of DT51 at normal condition and 10 hours of ABA treatment, respectively, whereas, this expression in MTD720 roots was 195- and 67-folds higher than those of DT51. Under drought stress, high transcript of this gene was also observed in both tissues of MTD720 relative to that of DT51. Together, GmHK07 is considered as a potential negative regulator not only in drought tolerance but also in ABA response, and can be used in genetic engineering approach to enhance plant adaptation to abiotic stresses.