Genome-wide identification, comparative analysis and functional roles in flavonoid biosynthesis of cytochrome P450 superfamily in pear (Pyrus spp.)

Abstract

Background The cytochrome P450 (CYP) superfamily is the largest enzyme metabolism family in plants identified to date, and it is involved in many biological processes, including secondary metabolite biosynthesis, hormone metabolism and stress resistance. However, the P450 gene superfamily has not been well studied in pear (Pyrus spp.). Results Here, the comprehensive identification and a comparative analysis of P450 superfamily members were conducted in cultivated and wild pear genomes. In total, 338, 299 and 419 P450 genes were identified in Chinese white pear, European pear and the wild pear, respectively. Based on the phylogenetic analyses, pear P450 genes were divided into ten clans, comprising 48 families. The motif and gene structure analyses further supported this classification. The expansion of the pear P450 gene family was attributed to whole-genome and single-gene duplication events. Several P450 gene clusters were detected, which have resulted from tandem and proximal duplications. Purifying selection was the major force imposed on the long-term evolution of P450 genes. Gene dosage balance, subfunctionalization and neofunctionalization jointly drove the retention and functional diversification of P450 gene pairs. Based on the association analysis between transcriptome expression profiles and flavonoid content during fruit development, three candidate genes were identified as being closely associated with the flavonoid biosynthesis, and the expression of one gene was further verified using qRT-PCR and its function was validated through transient transformation in pear fruit. Conclusions The study results provide insights into the evolution and biological functions of P450 genes in pear.

Comparison of the Effect of Pruning on Plant Growth and Transcriptome Profiles in Different Tea Varieties

“…The reason for the variable growth of tea plant may be related to genes, and many genes are involved in plant growth, such as CYP450 family members and 9-cis epoxy carotenoid dioxygenase (NCED), etc. Overexpression of the At CYP79B2 gene in Arabidopsis thaliana showed phenotypes of dwarfism and sterility, which are also typical of the traits of growth hormone accumulation in large quantities, and it was further determined that At CYP79B2 is involved in catalyzing the growth hormone synthesis pathway [21]. NCED is a member of the family of carotenoid cleavage dioxygenases (CCDs) and considered a key enzyme in ABA biosynthesis [23].…”

“…The most significantly enriched pathways were those of the ZCCK and EWCK groups, followed by those of the ZC and EW groups. All four transcriptome datasets identified cytochrome P450 family genes involved in the synthesis, catabolism, and production of most phytohormones and many secondary metabolites [21].…”