Genome-wide analysis of the GDSL esterase/lipase (GELP) family in banana (Musa acuminata) and functional validation of MaGELP81 as a candidate positive regulator associated with resistance to Fusarium oxysporum f. sp. cubense tropical race 4.
TL;DR
This study provides a comprehensive view of the composition and evolutionary features of the banana GELP family, elucidates their potential roles in responses to Foc TR4 stress, and pinpoints MaGELP81 as a key candidate gene.
Abstract
Background
Fusarium wilt is among the most destructive diseases threatening global banana production and severely undermines the industry's sustainability. GDSL-type esterase/lipase proteins (GELPs) are lipid-hydrolyzing enzymes with diverse substrate specificities that catalyze the generation and transduction of lipid-derived signals, playing key roles in plant defense responses.
Results
Here, we systematically identified members of the GELP gene family in the banana genome and conducted an integrated analysis of their phylogeny, gene structures, and promoter cis-elements. After manual correction of incorrectly annotated gene structures, a total of 92 MaGELP genes were identified and found to be unevenly distributed across 11 chromosomes, with most located near chromosome ends. Phylogenetic analysis combined with collinearity evidence indicated that the family is evolutionarily conserved. Promoter analysis revealed an enrichment of cis-elements associated with light responsiveness and MeJA-mediated signaling. Expression profiling showed that MaGELP81 is strongly up-regulated (fold change > 1.5) by infection with Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) and by SA, JA, and ET treatments, with pronounced differential expression between resistant and susceptible cultivars (fold change > 1.6). Subcellular localization assays demonstrated that MaGELP81 resides at the vacuolar membrane. When MaGELP81 was overexpressed in Arabidopsis thaliana, three independent high-expression lines exhibited better growth after Foc TR4 inoculation and significantly reduced disease incidence, severity scores, and disease index compared with the wild type, suggesting that MaGELP81 may be associated with enhanced resistance to Foc TR4.
Conclusion
Collectively, this study provides a comprehensive view of the composition and evolutionary features of the banana GELP family, elucidates their potential roles in responses to Foc TR4 stress, and pinpoints MaGELP81 as a key candidate gene. These findings offer foundational insight into the molecular interplay between lipid metabolism and plant immune signaling and provide valuable genetic resources for the molecular breeding of Foc TR4-resistant banana.