Cinnamate-4-Hydroxylase Gene Is Involved in the Step of Lignin Biosynthesis in Chinese White Pear

Abstract

<jats:p>Lignin is the main component of stone cells, and stone cell content is one of the crucial factors for fruit quality in chinese white pear (<jats:italic>Pyrus</jats:italic> ×<jats:italic>bretschneideri</jats:italic>). The lignin biosynthesis pathway is complex and involves many enzymatic reactions. Cinnamate-4-hydroxylase [C4H (EC.1.14.13.11)] is an essential enzyme in lignin metabolism. This study was conducted to investigate the effect of bagging on lignin metabolism during fruit development in chinese white pear. The study showed that bagging had little effect on stone cell content, lignin content, C4H activity, and <jats:italic>C4H</jats:italic> gene expression and that there was a positive correlation between <jats:italic>C4H</jats:italic> gene expression and lignin content as well as stone cell content. Moreover, a full-length complementary DNA (cDNA) encoding <jats:italic>C4H</jats:italic> (<jats:italic>PbrC4H</jats:italic>, GenBank accession number KJ577541.1) was isolated from chinese white pear fruit. The cDNA is 1515 bp long and encodes a protein of 504 amino acids. Sequence alignment suggested that the deduced protein belongs to the <jats:italic>P450</jats:italic> gene family and that C4H might be located subcellularly in the cell membrane. The results indicate that bagging cannot change the lignin and stone cell content significantly and that C4H catalyzes a step in lignin biosynthesis. These findings provide certain theoretical references and practical criteria for improving the quality of chinese white pear.</jats:p>

Genome-wide analysis of phenylalanine ammonia-lyase (PAL) gene family in five Rosaceae plants and expression analysis and functional identification of Chinese white pear

“…It has been found that lignin plays a key role in the formation of stone cells. Lignin deposits on the cell wall of pear fruits, making the secondary cell wall thicker (Cai et al, 2010;Tao et al, 2015). The present study found that there is a strong correlation between the formation of stone cells and lignin biosynthesis, which supported the view that lignin plays a vital function in stone cell biosynthesis .…”

Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri) fruit

“…Fruit bagging can affect the content of stone cells in pear cultivation, which is likely because the bag alters the light intensity. This directly affects expression of CCR and CAD members with light response elements in fruit and changes lignin metabolism, which ultimately affects the development of stone cells ( Tao et al, 2015 ; Wang et al, 2017b ). Although light cannot reach the middle region of pear fruit, the effect of light may be transduced from photoreceptors in the peel, similar to what occurs in underground tissues (roots, storage roots), to internal cells by phytochrome and cryptochrome.…”

Bacillus licheniformis strain POT1 mediated polyphenol biosynthetic pathways genes activation and systemic resistance in potato plants against Alfalfa mosaic virus

“…Likewise, the up-regulation of C3H with the transcriptional expression level of 6.453-, 7.061-and 8.111-fold was reported in T2, T3 and T4, respectively. HCT and C3H involved in lignin biosynthesis in the plant cell wall 56,63 . Thus, the induction of transcriptional expression of these genes shows their protective role against AMV and suggests that the potato plant can use the lignifications as one of its defense to resist the viral infection and movement.…”

“…Besides its role in plant defense, PAL involved in the biosynthesis of salicylic acid (SA) that plays an essential role in the induction of plant systemic resistance pathogens 50 , 53 – 55 . Moreover, through enhancing the accumulation of lignin in the plant cell walls, C4H plays a role in increasing plant defense 56 , 57 . Consequently, the induction of PAL and C4H transcripts in T3 and T4 treatment suggesting that POT1 is a good elicitor activated ISR that is associated with SA and secondary metabolites, precursors of chlorogenic acid and flavonoids, biosynthesis in potato tissues.…”