Overexpression of the autophagy-related gene TaATG8 enhances wheat seedling tolerance to salt stress by increasing autophagic activity

Context. Salt stress harms plant growth and limits crop productivity. Autophagy is a material decomposition and metabolism pathway that is central to regulating plant responses to environmental stimuli and may be employed in plant breeding for stress tolerance. The autophagy-related gene ATG8 has become an essential tool for monitoring autophagic activity. Aims. We aimed to determine the effects of increased autophagic activity via overexpression of ATG8 on tolerance of wheat (Triticum aestivum L.) seedlings to NaCl stress. Methods. Salt-tolerant wheat cv. Jimai22 was used to produce TaATG8a-overexpressing wheat seedlings using Foxtail mosaic virus based virus-mediated overexpression technology. TaATG8a-overexpressing seedlings were exposed to NaCl stress for 6 days. Key results. Overexpression of TaATG8a enhanced autophagic activity and improved salt stress tolerance of wheat seedlings. Overexpression of TaATG8a also reduced damage to photosystem II, reduced excess accumulation of reactive oxygen species, increased the activities of superoxide dismutase, peroxidase and catalase, and suppressed programmed cell death in wheat seedling leaves during NaCl treatment. Conclusions. Overexpression of TaATG8a conferred higher tolerance of wheat seedlings to NaCl stress and suppressed salt-induced programmed cell death, accompanied by increased autophagic activity. Implications. This study provides genetic resources and a theoretical basis for stress tolerance breeding in wheat.