The mitogen-activated protein kinase （MAPK）, a key signal transduction component in the MAPK cascade pathway, regulates a variety of physiological activities in eukaryotes. However, little is known of the role MAPK ...The mitogen-activated protein kinase （MAPK）, a key signal transduction component in the MAPK cascade pathway, regulates a variety of physiological activities in eukaryotes. However, little is known of the role MAPK plays in phytopathogenic fungi. In this research, we cloned the MAPK gene STK1 from the northern corn leaf blight pathogen Setosphaeria turcica and found that the gene shared high homology with the high osmolality glycerol （HOG） MAPK gene HOG1 of Saccharomy- ces cerevisiae. In addition, gene knockout technology was employed to investigate the function of STKI. Gene knockout mutants （KOs） were found to have altered hyphae morphology and no conidiogenesis, though they did show similar radial growth rate compared to the wild-type strain （WT）. Furthermore, microscope observations indicated that STK1 KOs did not form normal appressoria at 48 h post-inoculation on a hydrophobic surface. STK1 KOs had reduced virulence, a significantly altered Helminthosporium turcicum （HT）-toxin composition, and diminished pathogenicity on the leaves of susceptible inbred corn OH43. Mycelium morphology appeared to be significantly swollen and the radial growth rates of STK1 KOs declined in comparison with WT under high osmotic stress. These results suggested that STK1 affects the hyphae development, conidiogenesis, and pathogenicity of S. turcica by regulating appressorium development and HT-toxin biosynthesis. Moreover, the gene appears to be involved in the hypertonic stress response in S. turcica.展开更多
[ Objectives] As a traditional inoculation method of rice sheath blight, rice relative lesion height method needs rice grow to late tillering or heading stage and then inoculate in vivo, which is time-consuming and is...[ Objectives] As a traditional inoculation method of rice sheath blight, rice relative lesion height method needs rice grow to late tillering or heading stage and then inoculate in vivo, which is time-consuming and is difficult to control the testing conditions, so it is urgent to search a better alternative method. [ Methods] With rice relative lesion height method （ in vivo inoculation） as the control, the pathogenicity and crude toxin activity of Rhizoctonia solani were determined by rice detached leaf sheath method and rice detached leaf method, to compare the correlation of in vivo and in vitro inoculation. [Results] Rice detached leaf method and rice detached leaf sheath method had significantly positive correlation with rice relative lesion height method, and the determination results of rice detached leaf method and rice detached leaf sheath method could reflect the pathogenicity and crude toxin activity of R. solani accurately. [ Conclusions] Rice detached leaf method and rice detached leaf sheath method are easy to operate and control testing conditions, and could be used as alternative methods to determine pathogenicity and etude toxin activity of R. solani.展开更多
It was found that the marine yeast strain YF07b could secrete a large amount of killer toxin against a pathogenic yeast strain WCY which could cause milky disease in Portunus trituberculcttus. The marine yeast strain ...It was found that the marine yeast strain YF07b could secrete a large amount of killer toxin against a pathogenic yeast strain WCY which could cause milky disease in Portunus trituberculcttus. The marine yeast strain YF07b was identified to be Pichia anomala according to the results of routine yeast identification and 18S rDNA and ITS sequences. The gene encoding killer toxin in the marine yeast strain YF07b was amplified by PCR technology. After sequencing, the results show that an open reading frame, consisting of 1 281 bp, encoded a presumed protein of 427 amino acids. The sequence of the cloned gene was found to have 99% match with that of the gene encoding killer toxin in Pichia anomalas strain K. A signal peptide including 17 amino acids appeared in the N-terminal domain of the killer toxin. Therefore, the mature protein consisted of 410 amino acids, its molecular mass was estimated to be 47.4 ku and its isoelctronic point was 4.5.展开更多
基金supported by the National Natural Science Foundation of China (31171805 and 31371897)
文摘The mitogen-activated protein kinase （MAPK）, a key signal transduction component in the MAPK cascade pathway, regulates a variety of physiological activities in eukaryotes. However, little is known of the role MAPK plays in phytopathogenic fungi. In this research, we cloned the MAPK gene STK1 from the northern corn leaf blight pathogen Setosphaeria turcica and found that the gene shared high homology with the high osmolality glycerol （HOG） MAPK gene HOG1 of Saccharomy- ces cerevisiae. In addition, gene knockout technology was employed to investigate the function of STKI. Gene knockout mutants （KOs） were found to have altered hyphae morphology and no conidiogenesis, though they did show similar radial growth rate compared to the wild-type strain （WT）. Furthermore, microscope observations indicated that STK1 KOs did not form normal appressoria at 48 h post-inoculation on a hydrophobic surface. STK1 KOs had reduced virulence, a significantly altered Helminthosporium turcicum （HT）-toxin composition, and diminished pathogenicity on the leaves of susceptible inbred corn OH43. Mycelium morphology appeared to be significantly swollen and the radial growth rates of STK1 KOs declined in comparison with WT under high osmotic stress. These results suggested that STK1 affects the hyphae development, conidiogenesis, and pathogenicity of S. turcica by regulating appressorium development and HT-toxin biosynthesis. Moreover, the gene appears to be involved in the hypertonic stress response in S. turcica.
基金Supported by National Natural Science Foundation of China(31160352,31360423)Science and Technology Innovation Team Support Plan for Colleges and Universities in Yunnan Province(YJK[2014]22)
文摘[ Objectives] As a traditional inoculation method of rice sheath blight, rice relative lesion height method needs rice grow to late tillering or heading stage and then inoculate in vivo, which is time-consuming and is difficult to control the testing conditions, so it is urgent to search a better alternative method. [ Methods] With rice relative lesion height method （ in vivo inoculation） as the control, the pathogenicity and crude toxin activity of Rhizoctonia solani were determined by rice detached leaf sheath method and rice detached leaf method, to compare the correlation of in vivo and in vitro inoculation. [Results] Rice detached leaf method and rice detached leaf sheath method had significantly positive correlation with rice relative lesion height method, and the determination results of rice detached leaf method and rice detached leaf sheath method could reflect the pathogenicity and crude toxin activity of R. solani accurately. [ Conclusions] Rice detached leaf method and rice detached leaf sheath method are easy to operate and control testing conditions, and could be used as alternative methods to determine pathogenicity and etude toxin activity of R. solani.
基金This research was supported by the National Natural Science Foundation of China under contract No.30670058
文摘It was found that the marine yeast strain YF07b could secrete a large amount of killer toxin against a pathogenic yeast strain WCY which could cause milky disease in Portunus trituberculcttus. The marine yeast strain YF07b was identified to be Pichia anomala according to the results of routine yeast identification and 18S rDNA and ITS sequences. The gene encoding killer toxin in the marine yeast strain YF07b was amplified by PCR technology. After sequencing, the results show that an open reading frame, consisting of 1 281 bp, encoded a presumed protein of 427 amino acids. The sequence of the cloned gene was found to have 99% match with that of the gene encoding killer toxin in Pichia anomalas strain K. A signal peptide including 17 amino acids appeared in the N-terminal domain of the killer toxin. Therefore, the mature protein consisted of 410 amino acids, its molecular mass was estimated to be 47.4 ku and its isoelctronic point was 4.5.
