Grapevine VviERF105 promotes tolerance to abiotic stress and is degraded by the E3 ubiquitin ligase VviPUB19

Abstract

ERF transcription factors comprise the largest subfamily of the AP2/ERF transcription factors and are widely involved in processes of plant growth and development. In the grapevine Vitis vinifera, many ERFs have additionally been reported to play important functions in stress response. In this study, we cloned and characterized the ERF gene VviERF105 from V. vinifera. VviERF105 encodes a nuclear-localized, canonical ERF protein and is expressed strongly in stems and leaves. VviERF105 is induced by cold (4 °C), drought, and NaCl treatments. Heterologous expression of VviERF105 in transgenic Arabidopsis increased resistance to freezing, drought and salt stress as well as tolerance to growth on mannitol and NaCl, and this was associated with enhanced expression of abiotic stress-related genes. Overexpression of VviERF105 in transgenic grapevine callus increased tolerance to mannitol and NaCl. Heterologous expression of VviERF105 in Arabidopsis also delayed flowering and senescence and increased leaf thickness and the number of trichomes. Analysis of co-expressed genes indicated a relationship between VviERF105 and the E3 ubiquitin ligase VviPUB19. Yeast two-hybrid, BiFC and Co-IP analysis revealed that VviPUB19 interacts with VviERF105 through the UND domain of VviPUB19. VviERF105 was subject to degradation dependent on VviPUB19 and the 26 S proteasome. In summary, our study showed that VviERF105 is involved in regulating plant growth and development and response to abiotic stresses (freezing, drought and salt), and VviERF105 protein interacts with and is degraded by VviPUB19.