Function and defense mechanisms of wheat 14-3-3 protein TaGF14a in stripe rust resistance

As critical regulatory elements in plant signaling transduction, 14-3-3 proteins orchestrate defense responses against biotic and abiotic stresses. This study investigates the functional role of TaGF14a in wheat's immune response to Puccinia striiformis f. sp. tritici (Pst), providing novel genetic insights for stripe rust resistance breeding.

Phylogenetic analysis revealed a close evolutionary relationship between TaGF14a and rice OsGF14a. Subcellular localization studies demonstrated that the protein was located in the in the nucleus, cytoplasm, and plasma membrane. Pathogen challenge experiments showed significant induction of TaGF14a expression following Pst inoculation. Virus-induced gene silencing (VIGS) technology was used to silence TaGF14a, which resulted in expanded necrotic lesions and compromised fungal containment during incompatible interactions. Concurrently, we observed downregulation of pathogenesis-related genes (TaPR1, TaPR3) and altered expression patterns in reactive oxygen species (ROS) metabolism genes (TaCAT, TaSOD). Protein interaction assays identified novel associations between TaGF14a and key defense components: xylanase inhibitor and E3 ubiquitin ligase RGLG2, suggesting coordinated regulation of cell wall reinforcement and proteasomal degradation pathways. Furthermore, TaGF14a exhibited dual stress responsiveness, showing 3.3-fold induction under methyl jasmonate treatment and 3-fold increase under cold stress (4 °C).

This comprehensive analysis advances our understanding of 14-3-3 proteins in cereal-pathogen interactions and provides molecular targets for durable disease resistance strategies.