Two Monolignoid Biosynthetic Genes 4-coumarate:coenzyme A Ligase (4CL) and P-coumaric Acid 3-hdroxylase (C3H) Involved in Lignin Accumulation in Pear Fruits

One of the most important factors impacting the quality of pear fruit is the presence of stone cells and lignin. Lignin is the main component of stone cells in pear fruits. Two monolignoid biosynthetic genes () and () are involved in lignin accumulation in pear fruits. However, the functions of these genes in lignin biosynthesis were excluded in pear. In our study, we isolated and cloned (GenBank: KM455955.1) and (GenBank: KM373790.1) from pear, which contained 1644 bp encoded 54 amino acids (AA), and 1539 bp encoded 513 AA, respectively. The expression of and in led to an increase in cell wall thickness for intervascular fibers and xylem cells and lignin content. Overexpression of and in can significantly increase the expression of and with promotion of lignin biosynthesis. Taken together, our study's findings not only demonstrated the probable function of and in lignin biosynthesis but also laid the groundwork for future studies using molecular biological methods to control lignin production and the formation of stone cells in pear fruits.