病毒通过自身编码的蛋白以及与寄主因子的相互作用调控致病性，产生症状。在研究木槿褪绿环斑病毒时，我们发现并证实弱起始密码子CUG起始的p27在细胞中的表达，突变分析表明p27影响病毒引起的系统症状，缺失p27时，系统症状为轻微花叶，而非野生型病毒引起的褪绿环斑症状。本项目针对p27在病毒致病性中的功能特点，利用遗传学和分子生物学手段对其影响病毒系统症状的机理进行研究。通过Western blot和电子显微镜观察发现p27不影响病毒在细胞内的积累和分布，野生型病毒和突变体侵染均增加细胞内线粒体数目，使得过氧化酶体增生，相比较野生型病毒，p27不表达时寄主细胞内线粒体内膜发生形态变化；通过DAB染色，发现p27表达时系统叶片中细胞内过氧化氢积累显著增加；通过Northern blot和半定量RT-PCR发现p27不表达时，病毒侵染显著增加过氧化酶基因的转录和积累；将p27编码框转入模式植物拟南芥，获得10个转基因系，转基因植株在表型上没有变化，但有些转基因系子代种子发芽率显著降低。通过上述研究和分析，初步明确了p27在木槿褪绿环斑病毒侵染致病中的功能。

Viarl pathogenicity and symptom inducing are controlled and regulated by viral encoded protein and host factors. Previous study of Hibiscus chlorotic ringspot virus (HCRSV) identified a CUG started protein, p27, in HCRSV infected cells, and mutants analysis indicated that p27 was involved in systemic symptom expression, which changed from wildtype ringspot to mild mosaic. In this study,genetic and molecular biological methods were used to dissect the mechanism of p27 regulating systemic symptom. Firstly, p27 has no effect on the virus accumulation and distribution, and both HCRSV and p27 mutants infection increased the number of mitochondrion, induced peroxisome prolification, however, p27 mutants altered the shape of mitochondrion inner membrane. Second,DAB stain showed that p27 increased significantly the accumulation of H2O2 in systemic leves. Northern blot and semiquantitative RT-PCR confirmed that the transcirpt level of catalase gene increased significantly when there was no p27. Lastly, transgenic Arabidopsis lines expressing p27 were got and there was no obvious phenotype changes comparing to nontransgenic plants, but the gemination rates of progeny seeds decreased.These studies basically showed that p27 might increase the symptom severity in HCRSV infection.

病毒通过自身编码的蛋白以及与寄主因子的相互作用调控致病性，产生症状。在研究木槿褪绿环斑病毒时，我们发现并证实弱起始密码子CUG起始的p27在细胞中的表达，突变分析表明p27影响病毒引起的系统症状，缺失p27时，系统症状为轻微花叶，而非野生型病毒引起的褪绿环斑症状。本项目针对p27在病毒致病性中的功能特点，利用遗传学和分子生物学手段对其影响病毒系统症状的机理进行研究。通过Western blot和电子显微镜观察发现p27不影响病毒在细胞内的积累和分布，野生型病毒和突变体侵染均增加细胞内线粒体数目，使得过氧化酶体增生，相比较野生型病毒，p27不表达时寄主细胞内线粒体内膜发生形态变化；通过DAB染色，发现p27表达时系统叶片中细胞内过氧化氢积累显著增加；通过Northern blot和半定量RT-PCR发现p27不表达时，病毒侵染显著增加过氧化酶基因的转录和积累；将p27编码框转入模式植物拟南芥，获得10个转基因系，转基因植株在表型上没有变化，但有些转基因系子代种子发芽率显著降低。通过上述研究和分析，初步明确了p27在木槿褪绿环斑病毒侵染致病中的功能。