Wylie Stephen J, Zhang Chao, Long Vicki, Roossinck Marilyn J, Koh Shu Hui, Jones Michael G K, Iqbal Sadia, Li Hua
Plant Biotechnology Research Group-Virology, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia; Plant Biotechnology Research Group-Pests, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia.
College of Plant Protection, Northwest Agriculture and Forestry University, Yangling, Shaanxi Province, China.
PLoS One. 2015 Mar 30;10(3):e0121787. doi: 10.1371/journal.pone.0121787. eCollection 2015.
Nicotiana benthamiana is a model plant utilised internationally in plant virology because of its apparent hyper-susceptibility to virus infection. Previously, others showed that all laboratory accessions of N. benthamiana have a very narrow genetic basis, probably originating from a single source. It is unknown if responses to virus infection exhibited by the laboratory accession are typical of the species as a whole. To test this, 23 accessions of N. benthamiana were collected from wild populations and challenged with one to four viruses. Additionally, accessions of 21 other Nicotiana species and subspecies from Australia, one from Peru and one from Namibia were tested for susceptibility to the viruses, and for the presence of a mutated RNA-dependent RNA polymerase I allele (Nb-RDR1m) described previously from a laboratory accession of N. benthamiana. All Australian Nicotiana accessions tested were susceptible to virus infections, although there was symptom variability within and between species. The most striking difference was that plants of a laboratory accession of N. benthamiana (RA-4) exhibited hypersensitivity to Yellow tailflower mild mottle tobamovirus infection and died, whereas plants of wild N. benthamiana accessions responded with non-necrotic symptoms. Plants of certain N. occidentalis accessions also exhibited initial hypersensitivity to Yellow tailflower mild mottle virus resembling that of N. benthamiana RA-4 plants, but later recovered. The mutant Nb-RDR1m allele was identified from N. benthamiana RA-4 but not from any of 51 other Nicotiana accessions, including wild accessions of N. benthamiana, demonstrating that the accession of N. benthamiana used widely in laboratories is unusual.
本氏烟草是一种在植物病毒学领域被国际广泛应用的模式植物，因为它对病毒感染表现出明显的高度易感性。此前，其他人发现所有本氏烟草的实验室种质都有非常狭窄的遗传基础，可能起源于单一来源。尚不清楚实验室种质对病毒感染的反应是否代表了该物种的整体情况。为了验证这一点，从野生种群中收集了23份本氏烟草种质，并用一到四种病毒进行挑战。此外，还对来自澳大利亚的21种其他烟草物种和亚种的种质、一份来自秘鲁的种质和一份来自纳米比亚的种质进行了病毒易感性测试，以及检测是否存在先前在本氏烟草实验室种质中描述的突变RNA依赖性RNA聚合酶I等位基因（Nb-RDR1m）。所有测试的澳大利亚烟草种质都对病毒感染敏感，尽管不同物种之间和物种内部存在症状差异。最显著的差异是，本氏烟草实验室种质（RA-4）的植株对黄尾花温和斑驳烟草花叶病毒感染表现出超敏反应并死亡，而野生本氏烟草种质的植株则表现出非坏死症状。某些西方烟草种质的植株对黄尾花温和斑驳病毒也表现出类似于本氏烟草RA-4植株的初始超敏反应，但随后恢复。在本氏烟草RA-4中鉴定出了突变的Nb-RDR1m等位基因，但在包括本氏烟草野生种质在内的其他51种种质中均未发现，这表明实验室广泛使用的本氏烟草种质是不同寻常的。
