Superfamily of glycolipid transfer proteins (GLTPs): Accelerated cell death 11-like (ACD11) enhances salt tolerance in apple

For adaptation to challenging environments, plants have evolved various response mechanisms, such as inducing the expression of many stress genes, thereby increasing the resistance. Accelerated cell death (ACD) genes have been widely studied in plant senescence and defense responses. However, there are few reports on the role of ACD genes in abiotic stresses in plants. In this experiment, ACD11 was successfully isolated from apples (Malus baccata) and found to be mainly expressed in apple fruits and roots. The response elements of abiotic stresses were also found in the promoter of MbACD11. Furthermore, MbACD11 expression was induced by various abiotic stresses, especially salt treatment. After overexpression of MbACD11 in apple seedlings, callis and Arabidopsis thaliana, all showed enhanced tolerance to salt stress. Under salt conditions, MbACD11-OE showed higher fresh weight and chlorophyll content compared to the WT. It also exhibited lower relative electrical conductivity, malondialdehyde (MDA) content, and reactive oxygen species (ROS) accumulation than the WT. The expression of salt stress-related genes was higher in MbACD11-OE apple seedlings than in WT. In salt stress condition, the apple MbACD11 gene reduced ROS accumulation and affected the expression of salt stress-related genes, hence enhancing tolerance.