The Maize Gene ZmGLYI-8 Confers Salt and Drought Tolerance in Transgenic Arabidopsis Plants

Methylglyoxal (MG), a highly reactive and cytotoxic α-oxoaldehyde compound, can over-accumulate under abiotic stress, consequently injuring plants or even causing death. Glyoxalase I (GLYI), the first enzyme of the glyoxalase pathway, plays multiple roles in the detoxification of MG and in abiotic stress responses. However, the <i>GLY1</i> gene in maize has been little studied in response to abiotic stress. In this study, we screened a glyoxalase I gene (<i>ZmGLYI-8</i>) and overexpressed in <i>Arabidopsis</i>. This gene was localized in the cytoplasm and can be induced in maize seedlings under multiple stress treatments, including salt, drought, MG, ABA, H₂O₂ and high temperature stress. Phenotypic analysis revealed that after MG, salt and drought stress treatments, overexpression of <i>ZmGLYI-8</i> increased the tolerance of transgenic <i>Arabidopsis</i> to MG, salt and drought stress. Furthermore, we demonstrated that the overexpression of <i>ZmGLYI-8</i> scavenges accumulated reactive oxygen species, detoxifies MG and enhances the activity of antioxidant enzymes to improve the resistance of transgenic <i>Arabidopsis</i> plants to salt and drought stress. In summary, this study preliminarily elucidates the molecular mechanism of the maize <i>ZmGLYI-8</i> gene in transgenic <i>Arabidopsis</i> and provides new insight into the breeding of salt- and drought-tolerant maize varieties.