Find in Library

<i>Lolium multiflorum</i> is one of the world-famous forage grasses with rich biomass, fast growth rate and good nutritional quality. However, its growth and forage yield are often affected by drought, which is a major natural disaster all over the world. MYB transcription factors have some specific roles in response to drought stress, such as regulation of stomatal development and density, control of cell wall and root development. However, the biological function of MYB in <i>L. multiflorum</i> remains unclear. Previously, we elucidated the role of <i>LmMYB1</i> in enhancing osmotic stress resistance in <i>Saccharomyces cerevisiae</i>. Here, this study elucidates the biological function of <i>LmMYB1</i> in enhancing plant drought tolerance through an ABA-dependent pathway involving the regulation of cell wall development and stomatal density. After drought stress and ABA stress, the expression of <i>LmMYB1</i> in <i>L. multiflorum</i> was significantly increased. Overexpression of <i>LmMYB1</i> increased the survival rate of <i>Arabidopsis thaliana</i> under drought stress. Under drought conditions, expression levels of drought-responsive genes such as <i>AtRD22, AtRAB</i> and <i>AtAREB</i> were up-regulated in OE compared with those in WT. Further observation showed that the stomatal density of OE was reduced, which was associated with the up-regulated expression of cell wall-related pathway genes in the RNA-Seq results. In conclusion, this study confirmed the biological function of <i>LmMYB</i>1 in improving drought tolerance by mediating cell wall development through the ABA-dependent pathway and thereby affecting stomatal density.