Abstract
Background Enzymes of chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. Some of these metabolites have a wide variety of biological functions such as flower pigmentation, protection against UV radiation, pathogen defense, auxin transport and pollen fertility. CHS also showed significant correlation to the accumulation patterns of anthocyanin. The peel color mainly determined by the content of anthocyanin, is a majority economic trait for eggplant affected by heat stress. Results A total of 7 CHS ( SmCHS1-7 ) putative genes were identified in genome-wide of eggplant ( S. melongena L . ). The SmCHS genes distribute on 7 scaffolds and were classified into 3 clusters. Phylogenetic relationships analysis showed that 73 CHS genes from 7 Solanaceae species were classified into 10 groups. SmCHS5 , SmCHS6 and SmCHS7 were continuously down-regulated under 38℃ and 45℃ treatment, while SmCHS4 was up-regulated under 38℃ but little change at 45℃ in peel. Expression profiles of anthocyanin biosynthesis key genes families showed that the PAL, 4CL and AN11 genes were mainly expressed in all five tissues. CHI, F3H, F3’5’H, DFR, 3GT and bHLH1 genes were expressed in flower and peel. Under heat stress, 52 key genes expression level were reduced under heat stress. By contrast, expression patterns of eight key genes similar to SmCHS4 up-regulated at the 38℃-3h. Conclusions Comparative analysis of putative CHS protein biochemical characteristics, cis -regulatory elements, regulatory network revealed that SmCHS genes family have conservation gene structure and functional diversification. SmCHS showed two or more expression patterns and execute multiple functions to regulate anthocyanin content. Combined with regulatory networks, it is possible to further understand the regulation mechanism of peel color in eggplant.
Dynamics of mobile element activity in chalcone synthase loci in the common morning glory (Ipomoea purpurea)
