RESUMO
The calcium-dependent protein kinases (CDPKs) play vital roles in plant response to various environmental stimuli. Here, we investigated the function of Arabidopsis AtCPK1 in response to salt and drought stress. The loss-of-function cpk1 mutant displayed hypersensitive to salt and drought stress, whereas overexpressing AtCPK1 in Arabidopsis plants significantly enhanced the resistance to salt or drought stress. The reduced or elevated tolerance of cpk1 mutant and AtCPK1-overexpressing lines was confirmed by the changes of proline, malondialdehyde (MDA) and H2O2. Real-time PCR analysis revealed that the expression of several stress-inducible genes (RD29A, COR15A, ZAT10, APX2) down-regulated in cpk1 mutant and up-regulated in AtCPK1-overexpressing plants. These results are likely to indicate that AtCPK1 positively regulates salt and drought stress in Arabidopsis.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/fisiologia , Secas , Proteínas Quinases/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Mutação/genética , Fenótipo , Plantas Geneticamente Modificadas , Polietilenoglicóis/farmacologia , Prolina/metabolismo , Transcrição Gênica/efeitos dos fármacosRESUMO
Apple mosaic disease has a great influence on apple production. In this study, an investigation into the incidence of apple mosaic disease in southwest China was performed, and the pathogen associated with the disease was detected. The results show that 2869 apple trees with mosaic disease were found in the Sichuan, Yunnan, and Guizhou Provinces, with an average incidence of 9.6%. Although apple mosaic virus (ApMV) is widespread in apples worldwide, the diseased samples were negative when tested for ApMV. However, a novel ilarvirus (apple necrotic mosaic virus, ApNMV) was identified in mosaic apple leaves which tested negative for ApMV. RT-PCR analysis indicated that ApNMV was detected in 322 out of 357 samples with mosaic symptoms. Phylogenetic analysis of coat protein (CP) sequences of ApNMV isolates suggested that, compared with ApMV, ApNMV was closer to prunus necrotic ringspot virus (PNRSV). The CP sequences of the isolates showed the diversity of ApNMV, which may enable the virus to adapt to the changeable environments. In addition, the pathology of mosaic disease was observed by microscope, and the result showed that the arrangement of the tissue and the shape of the cell, including the organelle, were seriously destroyed or drastically changed.