Effects of anthocyanin pigment on salt resistance reaction in perilla frutescens

Oxidative stress, caused by the generation and accumulation of reactive oxygen species, is a common environmental stress factor that inhibits plant growth. This study examined how anthocyanin pigment, an antioxidative substance, changes under salt stress conditions and how the antioxidant properties of this pigment affect the salt resistance reaction in perilla （ Perilla frutescens ） plants. The results indicated that the salt tolerance of anthocyanin-rich red perilla plants was higher than that of anthocyanin-poor blue perilla plants. The maintenance of ion homeostasis, which corresponds to ionic or osmotic damage, was not the main function of anthocyanin. Instead, the pigment exhibited a secondary radical oxygen scavenging function. Specifically, the primary salt tolerance function of red perilla was associated with the antioxidant ability of anthocyanin, and the content of this antioxidative pigment nearly doubled as salt stress increased. Moreover, the antioxidant functions of active oxygen scavenging enzymes, mainly catalase, were subsequently detected. In conclusion, the results indicated that increasing amounts of anthocyanin pigment under salt