RESUMEN
Histone deacetylase 2 (HD2) is a unique family of histone deacetylases (HDACs) in plants. Despite evidence that certain HD2 family HDACs play an important role in plant growth and stress response, the coordination of HD2s in these processes remains largely unknown. We found that HD2-type, HD2A and HD2C coordinate to play a role in drought stress response in Arabidopsis. We showed that the hd2a.hd2c double mutant (Mac16) exhibit decreased drought survival and increased water loss as compared to the single mutants, hd2a and hd2c. Gene expression analysis showed that the ABI1 and ABI2 genes were upregulated and SLAC1 was downregulated which led to the modified stomatal functioning in the Mac16 as compared to the single mutants. Overexpression of HD2A and HD2C showed enhanced drought survival and decreased water loss. We also showed that the GA2ox1 and GA2ox2 genes, which are involved in the catabolism of bioactive gibberellic acids, were upregulated in the Mac16 as compared to the single mutants, which led to a decreased root growth in the Mac16. Furthermore, we showed that HD2A and HD2C can physically interact and increased genome-wide H3K9 acetylation was observed in the Mac16, compared to the single mutants. Overall, our investigation revealed that HD2A and HD2C coordinate to play a cumulative role in drought stress response and root growth in Arabidopsis.
RESUMEN
Histone deacetylases (HDACs) are vital epigenetic modifiers not only in regulating plant development but also in abiotic- and biotic-stress responses. Though to date, the functions of HD2C-an HD2-type HDAC-In plant development and abiotic stress have been intensively explored, its function in biotic stress remains unknown. In this study, we have identified HD2C as an interaction partner of the Cauliflower mosaic virus (CaMV) P6 protein. It functions as a positive regulator in defending against CaMV infection. The hd2c mutants show enhanced susceptibility to CaMV infection. In support, the accumulation of viral DNA, viral transcripts, and the deposition of histone acetylation on the viral minichromosomes are increased in hd2c mutants. P6 interferes with the interaction between HD2C and HDA6, and P6 overexpression lines have similar phenotypes with hd2c mutants. In further investigations, P6 overexpression lines, together with CaMV infection plants, are more sensitive to ABA and NaCl with a concomitant increasing expression of ABA/NaCl-regulated genes. Moreover, the global levels of histone acetylation are increased in P6 overexpression lines and CaMV infection plants. Collectively, our results suggest that P6 dysfunctions histone deacetylase HD2C by physical interaction to promote CaMV infection.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/virología , Caulimovirus/aislamiento & purificación , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas , Histona Desacetilasas/metabolismo , Hojas de la Planta/virología , Proteínas Virales/metabolismo , Virosis/virología , Acetilación , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Caulimovirus/fisiología , Proteínas de Unión al ADN/genética , Histona Desacetilasas/química , Histona Desacetilasas/genética , Fenotipo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/virología , Nicotiana/genética , Nicotiana/crecimiento & desarrollo , Nicotiana/metabolismo , Nicotiana/virología , Proteínas Virales/genética , Virosis/genética , Virosis/metabolismoRESUMEN
Cold stress is a major environmental constraint that restrains plant growth and productivity. To cope with cold stress, plants must be able to perceive a cold signal and regulate the expression of cold-regulated (COR) genes. In our recent study, we showed that Arabidopsis HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15) acts as a substrate receptor for CULLIN4-based ubiquitin E3 ligase complex to promote cold-induced histone deacetylase 2 C (HD2C) degradation that allows the activation of COR genes. Additionally, we found that POWERDRESS (PWR), a HOS15-interacting protein, is required for the association of HOS15 with COR gene chromatin and HD2C degradation. The HOS15/PWR complex interacts with and recruits CBF transcription factors to the promoters of COR genes. Collectively, our previous findings suggest that HOS15 and PWR function as positive regulators for the expression of COR genes, and promote cold tolerance. Accordingly, we herein discuss the role of PWR in cold tolerance.