Decreased susceptibility to viral disease of beta-1,3-glucanase-deficient plants generated by antisense transformation
Decreased susceptibility to viral disease of beta-1,3-glucanase-deficient plants generated by antisense transformation
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DOI：
10.1105/tpc.8.6.1001
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发表时间：
1996-06-01
期刊：
影响因子：
11.6
通讯作者：
Meins, F
中科院分区：
文献类型：
--
作者：
Beffa, RS;Hofer, RM;Meins, F
抗真菌I类β-1，3-葡聚糖酶被认为是植物对真菌感染的组成性和诱导性防御的一部分。出乎意料的是，通过反义转化产生的这些酶缺陷的突变体在Havana 425烟草对烟草花叶病毒（TMV）和欧洲烟草对烟草坏死病毒的局部损伤应答中显示出显著降低的损伤大小、损伤数量和病毒产量，这些突变体还表现出降低的花叶症状的严重程度，延迟症状的传播，并降低病毒产量在N。在一系列独立的转化体中，两种植物物种的反应中的疾病症状与β-1，3-葡聚糖酶含量正相关。综上所述，这些结果提供了直接证据，即β-1，3-葡聚糖酶在病毒发病机制中起作用，β-1，3-葡聚糖酶的底物胼胝质作为病毒传播的物理屏障，在β-1，3-葡聚糖酶缺陷的局部病变Havana 425宿主中，TMV诱导的病变中及其周围的胼胝质沉积增加，我们的研究结果提出了一种新的方法，基于宿主基因的反义转化，保护植物免受病毒感染，这些观察结果也提出了一个有趣的可能性，即病毒可以利用宿主对真菌感染的防御反应--产生β-1，3-葡聚糖酶--来促进自身的复制和传播。
Antifungal class I beta-1,3-glucanases are believed to be part of the constitutive and induced defenses of plants against fungal infection, Unexpectedly, mutants deficient in these enzymes generated by antisense transformation showed markedly reduced lesion size, lesion number, and virus yield in the local-lesion response of Havana 425 tobacco to tobacco mosaic virus (TMV) and of Nicotiana sylvestris to tobacco necrosis virus, These mutants also showed decreased severity of mosaic disease symptoms, delayed spread of symptoms, and reduced yield of virus in the susceptible response of N. sylvestris to TMV, The symptoms of disease in the responses of both plant species were positively correlated with beta-1,3-glucanase content in a series of independent transformants. Taken together, these results provide direct evidence that beta-1,3-glucanases function in viral pathogenesis, Callose, a substrate for beta-1,3-glucanase, acts as a physical barrier to the spread of virus, Callose deposition in and surrounding TMV-induced lesions was increased in the beta-1,3-glucanase-deficient, local-lesion Havana 425 host, suggesting as a working hypothesis that decreased susceptibility to virus resulted from increased deposition of callose in response to infection, Our results suggest novel means, based on antisense transformation with host genes, for protecting plants against viral infection, These observations also raise the intriguing possibility that viruses can use a defense response of the host against fungal infection-production of beta-1,3-glucanases-to promote their own replication and spread.