A Novel Non-Specific Lipid Transfer Protein Gene, , Enhanced Osmotic and Drought Tolerance by Regulating ROS Scavenging and Remodeling Lipid Profiles in Chinese Chestnut ( Blume).

Chestnut ( Blume) is an important economic tree owing to its tasty fruit and adaptability to environmental stresses, especially drought. Currently, there is limited information about non-specific lipid transfer protein (nsLTP) genes that respond to abiotic stress in chestnuts. Here, a chestnut , named , was identified and analyzed. The results showed that the CmnsLTP6.9 protein localized in the extracellular matrix had two splicing variants ( and ). Compared with , had an 87 bp deletion in the 5'-terminal. Overexpression of in enhanced tolerance to osmotic and drought stress. Upon exposure to osmotic and drought treatment, could increase reactive oxygen species (ROS)-scavenging enzyme activity, alleviating ROS damage. However, -overexpressing lines showed no significant differences in phenotype, ROS content, and related enzyme activities compared with the wild type (WT) under osmotic and drought treatment. Moreover, lipid metabolism analysis confirmed that, unlike , mainly altered and upregulated many fatty acyls and glycerophospholipids, which implied that and played different roles in lipid transference in the chestnut. Taken together, we analyzed the functions of and , and demonstrated that enhanced drought and osmotic stress tolerance through ROS scavenging and lipid metabolism.