Chloroplast-targeted Late Embryogenesis Abundant 1 Increases Alfalfa Tolerance to Drought and Aluminum
Published:18 Sep.2023 Source:Plant Physiology
Late embryogenesis abundant (LEA) proteins are important stress-response proteins that participate in protecting plants against abiotic stresses. Here, we investigated LEA group 3 protein MsLEA1, containing the typically disordered and α-helix structure, via overexpression and RNA interference (RNAi) approaches in alfalfa (Medicago sativa L.) under drought and aluminum (Al) stresses.
MsLEA1 highly expressed in leaves and localized in chloroplasts. Overexpressing MsLEA1 increased alfalfa tolerance to drought and Al stresses, but downregulating MsLEA1 decreased the tolerance. We observed a larger stomatal aperture and a lower water use efficiency in MsLEA1 RNAi lines compared to wild-type plants under drought stress. Photosynthetic rate, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, and superoxide dismutase (SOD) activity increased or decreased in MsLEA1-OE or -RNAi lines, respectively, under drought and Al stress.
Cu/Zn-SOD, Fe-SOD and Rubisco large subunit proteins (Ms1770) were identified as binding partners of MsLEA1, which protected chloroplast structure and function under drought and Al stress. These results indicate that MsLEA1 recruits and protects its target proteins (SOD and Ms1770) and increases alfalfa tolerance against drought and Al stresses.