Identification and Expression Analysis of the Expansin Gene Family in Wax Gourd (Benincasa hispida Cogn.)
YE Xinru, ZHANG Hui, WANG Bin, WEN Qingfang*
The thickness of wax gourd (Benincasa hispida Cogn.) flesh is one of the key factors affecting fruit size and yield, and is closely related to fruit cell expansion. Expansin is a type of cell wall remodeling protein that plays an important role in fruit expansion and other aspects. This study identified and analyzed members of the BhEXP gene family in wax gourd based on whole-genome sequencing results, investigating their expression pat- terns and regulatory mechanisms during wax gourd flesh development. Through microscopic observation of cell structures in wax gourd fruits with varying flesh thickness using sectioning methods, a significant correlation was found between fruit cell area and flesh thickness indicators. Identification of members of the wax gourd BhEXP gene family using biological methods, and analysis of chromosome localization, co-linearity, conserved motifs, gene structure, promoter cis-acting elements, and phylogeny of family members. Results indicate that 38 BhEXP family members were identified in the wax gourd genome, distributed across 11 chromosomes and grouped into four subfamilies, with significant collinearity observed among members. Phylogenetic analysis indicates that the wax gourd BhEXP gene family were closely related to cucumber (Cucumis sativus L.) and loofah (Luffa cylindrica L.). Promoter element prediction analysis revealed that the promoters of wax gourd BhEXP genes contain numerous elements responsive to light, methyl jasmonate, anaerobic induction, abscisic acid responses, and gibberellin. The expression characteristics of BhEXP genes during wax gourd fruit development were analyzed using qRT-PCR (real-time quantitative PCR) technology. Results indicate that BhEXPA13, BhEXPA18, BhEXLA6 and BhEXPB2 may play roles in wax gourd fruit development. This study provides a reference basis for further elucidating the biological functions of extensin genes in fruit development.
CN
EN