壳寡糖诱导烟草抗烟草花叶病毒的超微结构研究

Ultrastructure of induced resistance of tobacco to Tobacco mosaic virus by chito-oligosaccharides

电镜检查表明,接种烟草花叶病毒(TMV)表现系统侵染的烟草植株叶肉细胞和筛管内有大量病毒粒子和病毒结晶体,细胞质中出现髓鞘样结构、多泡体和次级囊泡。叶片薄壁细胞内叶绿体、线粒体等细胞器变形解体,膜结构增生。经壳寡糖(50μg/mL)诱导处理的烟草,系统症状减轻,叶肉细胞和筛管中病毒粒子显著减少,偶见病毒结晶体;叶肉细胞中细胞器基本完好,但叶绿体内出现较大的淀粉粒;液泡内和细胞间隙出现大量电子致密物质。在未接毒和未经壳寡糖处理的植株中未见此种电子致密物,其产生可能与诱导抗病性表达有关。

Tobacco plants were inoculated with Tobacco mosaic virus （TMV） and expressed systemic symptoms. A large amount of virus particles and crystals, together with myeloid bodies, multivesicular bodies and secondary vesicles were seen in mesophyll cells and/or sieve tubes of inoculated plants by EM observation. Chloroplasts, mitochondria, endoplasmic reticulum, and other organelles were also found to be distorted, disintegrated and collapsed in mesophyll cells of inoculated plants. It was evident that a few virus particles and relative structures （not clear） was produced, and organelles mostly remained unchanging in mesophyll cells of plants treated with chito-oligosaccharides （50 μg/mL）, but large starch grains occurred in chloroplasts. Besides, much electron-dense material deposited in vacuoles and middle lamella of mesophyll cells of treated plants, that was never seen in uninoculated or untreated plants. It was possible that the electron-dense material was related to induction of resistance to TMV.