Identification and analysis of lignin biosynthesis genes related to fruit ripening and stress response in banana ( L. AAA group, cv. Cavendish).

Background: Lignin is a key component of the secondary cell wall of plants, providing mechanical support and facilitating water transport as well as having important impact effects in response to a variety of biological and abiotic stresses.

Results: In this study, we identified 104 genes from ten enzyme gene families related to lignin biosynthesis in genome and found the number of gene family was the largest, while s had only two members. s retained the original members, and the number of s in lignin biosynthesis was significantly less than that of flavonoids. Segmental duplication existed in most gene families, except for s, and tandem duplication was the main way to expand the number of s. Moreover, the expression profiles of lignin biosynthesis genes during fruit development, postharvest ripening stages and under various abiotic and biological stresses were investigated using available RNA-sequencing data to obtain fruit ripening and stress response candidate genes. Finally, a co-expression network of lignin biosynthesis genes was constructed by weighted gene co-expression network analysis to elucidate the lignin biosynthesis genes that might participate in lignin biosynthesis in banana during development and in response to stresses.

Conclusion: This study systematically identified the lignin biosynthesis genes in the genome, providing important candidate genes for further functional analysis. The identification of the major genes involved in lignin biosynthesis in banana provides the basis for the development of strategies to improve new banana varieties tolerant to biological and abiotic stresses with high yield and high quality.