Proteomics and transcriptomic analyses provide new insights into the pectin polysaccharide biosynthesis in Premna...

Premna puberula Pamp. is a plant with similarities to both food and medicine, which has attracted the attention of researchers because of the rich pectin in its leaves. However, the mechanism of efficient pectin accumulation remains unclear. Through transcriptomic and proteomic analyses, this study investigated the differentially expressed genes and proteins associated with pectin during various developmental stages of P. puberula. The combined omics approach revealed that the majority of differential genes are mainly involved in the anabolic metabolism of primary and secondary metabolites. Notable differential pathways include starch and sucrose metabolism, amino acid sugar metabolism, and nucleotide sugar metabolism. The SWEET gene family was identified and analyzed, leading to the cloning of PpSWEET15 and subcellular localization. Overexpression of PpSWEET15 resulted in a significant decrease in sucrose content in leaves from 134.44 μg·g^-1 to <10 μg·g^-1. Glucose content decreased from 407.75 μg·g^-1 to 318.38 μg·g^-1, while fructose levels showed no significant difference between the two groups of leaves. This comprehensive transcriptomic and proteomic analysis provides valuable insights into the molecular mechanisms underlying the efficient accumulation of pectin in P. puberula.