Find in Library

Drought stress critically endangers the growth and development of crops. Glutathione S-transferase plays a vital role in response to abiotic stress. However, there are few studies on the role of glutathione S-transferase in maize drought stress. In this study, the significantly downregulated expression of <i>ZmGST26</i> in roots under drought stress was analyzed by qRT-PCR. Promoter analyses showed that there were several cis-acting elements related to drought stress and that were involved in oxidative response in the promoter region of <i>ZmGST26</i>. Subcellular localization results showed that <i>ZmGST26</i> was localized in the nucleus. The transgenic lines of the <i>Arabidopsis</i> over-expressing <i>ZmGST26</i> were more sensitive to drought stress and ABA in seed germination and inhibited ABA-mediated stomatal closure. Under drought stress, phenotypic analyses showed that the germination rate, root length and survival rate of <i>ZmGST26</i> overexpressing lines were significantly lower than those of wild-type lines. The determination of physiological and biochemical indexes showed that the water loss rate, malondialdehyde, O₂⁻ and H₂O₂ of the overexpression lines significantly increased compared with wild-type <i>Arabidopsis</i>, but the antioxidant enzyme activities (CAT, SOD and POD), and proline and chlorophyll contents were significantly reduced. Subsequently, the qRT-PCR analysis of drought stress-related gene expression showed that, under drought stress conditions, the expression levels of <i>DREB2A</i>, <i>RD29A</i>, <i>RD29B</i> and <i>PP2CA</i> genes in <i>ZmGST26</i> overexpression lines were significantly lower than those in wild-type <i>Arabidopsis</i>. In summary, <i>ZmGST26</i> reduced the drought resistance of plants by aggravating the accumulation of reactive oxygen species in <i>Arabidopsis</i>.