Gene expression analysis of PvDGK genes in response to Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), wounding and methyl jasmonate treatments in common bean.

Abstract

Plants have evolved complex defense mechanisms against biotic stressors, such as insect pests, involving chemical, physical, and molecular responses. These mechanisms, including producing secondary metabolites and activating specific signaling pathways, help mitigate damage and ensure survival under pest pressure. Many plants defense-related genes that play crucial roles in regulating defense responses have been identified in common bean. Phosphatidic acid (PA) is a vital lipid signaling molecule in plant stress responses, with diacylglycerol kinases (DGKs) play a key role in its production. In this study, we investigated the role of the PvDGK gene family in common bean under control, wounding, methyl jasmonate (MeJA, 100 µM), Helicoverpa armigera infestation, MeJA x wounding interaction and MeJA x H. armigera interaction. The larvae of H. armigera were reared under controlled conditions and used for infestation when they reached the fifth instar (L5). Expression levels of PvDGK1, PvDGK2, PvDGK3, PvDGK5a, PvDGK5b, and PvDGK6 genes were analyzed through qRT-PCR in leaves tissues. All PvDGK genes were upregulated in response to MeJA x H. armigera interaction. Notably, PvDGK2 was the most upregulated gene in the interaction of MeJA x H. armigera interaction, indicating its potential role in defense signaling. These findings provide the first evidence the importance of PvDGK genes in stress adaptation mechanisms in common bean and highlight their potential as targets for improving insect resistance. Future functional studies are crucial to fully elucidating the mechanisms through which these genes contribute to stress resilience and enhance our understanding of lipid signaling pathways in plant defense.