GmPLC8 enhances drought resistance in soybean by regulating stomatal closure

Soybean (<i>Glycine max</i> (L.) Merr.) is an economically important crop. Drought adversely affects nutrient acquisition and early vegetative development, thereby constraining the growth potential of soybean seedlings. Phospholipase C (PLC) participates in diverse biological processes, yet its function in soybeans has not been fully explored. In this study, we generated <i>GmPLC8</i>-overexpressing (OE) and <i>GmPLC8</i>-silenced soybean seedlings to investigate the function of <i>GmPLC8</i>. The results showed that <i>GmPLC8</i>-OE lines exhibited higher tolerance than wild-type seedlings, whereas <i>GmPLC8</i>-silenced seedlings were more sensitive. This was associated with reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels in <i>GmPLC8</i>-OE lines, and increased levels in <i>GmPLC8</i>-silenced seedlings. Further analysis revealed that drought caused smaller stomatal apertures and higher abscisic acid (ABA) content in <i>GmPLC8</i>-OE lines. Moreover, the transcription levels of ABA-related genes were upregulated in <i>GmPLC8</i>-OE lines. Taken together, these findings suggest that <i>GmPLC8</i> enhances drought tolerance in soybean by regulating stomatal aperture.