Genomic Analysis of the Caleosin Family in Theaceae Reveals Lineagespecific Evolutionary Patterns.

Introduction: Caleosins are recognized as the key proteins found in Lipid Droplets (LDs) and are crucial for the creation, maintenance, and breakdown of LDs. Nevertheless, our understanding of caleosins remains limited within Theaceae, a prominent botanical family encompassing economically significant tea and oil tea species.

Methods: In this research, we conducted a comprehensive genome-wide exploration and examination of the caleosin family in Theaceae species with sequenced genomes. The gene number of caleosin was similar among Theaceae species. Segmental duplication was the main form of caleosin expansion in Shuchazao (SCZ), Huangdan (HD), Biyun (BY), Tieguanyin (TGY), Longjing (LJ), C. lanceoleosa (Cla) and C. chekiangoleosa (CCH). Synteny analysis revealed one-to-more and more-to-one collinear relationships of caleosin genes among Theaceae species.

Results: Caleosins in Theaceae are categorized into either the H-family or the L-family, each exhibiting distinct motif structures and physicochemical properties. Expression analysis revealed an apparent flower-predominant expression pattern of caleosin genes in Theaceae species. In addition, most paralogous pairs displayed expression divergence.

Conclusion: This research enhanced our understanding of the lineage-specific evolution of caleosin genes in Theaceae, and is valuable for future functional analysis of this gene family in tea and oil-tea species.