CsCHLI plays an important role in chlorophyll biosynthesis of tea plant (<i>Camellia sinensis</i>)

Chlorophyll biosynthesis is a crucial biological process in plants, and chlorophyll content is one of the most important traits in the yield and quality of tea. Magnesium chelatase is a conserved enzyme complex responsible for the chlorophyll biosynthesis, which composed of the subnuit of CHLI, CHLD and CHLH. In this study, there were positive correlation between the expression of CsCHLI, chlorophyll content and chloroplast structure. The CsCHLI gene structure and functional domain indicated that, its cDNA length was 1275 bp, encodes 424 amino acids, consisted of cTP, AAA+ and AAA lid domain. Meanwhile, the subcellular localization demonstrated that CsCHLI localized in chloroplasts. In addition, protein-protein interaction analysis by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays indicated that CsCHLI could interact with CsCHLI to form homodimer, or perhaps interact with CsCHLD and CsCHLH to form heterodimer. Moreover, Arabidopsis transformation displayed that overexpression of CsCHLI could restore the etiolation phenotype of the atchli1 mutant. These findings provide the mechanistic function of CsCHLI and its implications in chlorophyll biosynthesis in tea plant.