Salicylic acid treatment enhances expression of chalcone isomerase gene and accumulation of corresponding flavonoids during fruit maturation of Lycium chinense

Chalcone isomerase (CHI) is a key gene involved in flavonoid biosynthesis, and flavonoids are important active ingredients in goji berries. Goji berry is a fruit with multi-nutrients consumed all over the world. Up to now, expression patterns of CHI gene and the regulation of flavonoid accumulation in goji berries still remain unknown. In this work, a CHI gene was cloned from fruits of Lycium chinense and was given the name LcCHI. Its relative expression and accumulation of total corresponding flavonoids during fruit maturation were investigated. During the fruit maturation, the expression of LcCHI gene increased gradually, and the accumulation of total flavonoids showed an overall upward trend. This study also showed that the expression of LcCHI gene and the content of total flavonoids in the goji berries could be up-regulated by exogenous salicylic acid (SA) treatment. A reactive oxygen species-dependent signaling pathway was suggested to be involved in this process. This research showed that the expression of LcCHI gene was positively correlated with total flavonoid accumulation and the regulation of them by SA could be a potential approach to produce more desired and valuable flavonoids in goji berries.