中文摘要：黄瓜绿斑驳花叶病毒（CGMMV）是一种烟草花叶病毒属病毒，可侵染包括西瓜在内的葫芦科植物。从CGMMV-SH中分离出一株CGMMV弱毒株（CGMMV-SH33b），用于保护甜瓜抵抗野生CGMMV。本研究结果表明：利用绿色荧光蛋白基因（GFP）使转基因烟草沉默；CGMMV-SH侵染明显抑制了GFP沉默，然而CGMMV-SH33b和其嵌合病毒导致了局部抑制。SH33b侵染的叶片中检测到的GFP mRNA、siRNA水平分别比CGMMV-SH中的低一些、高一些，为抑制提供了进一步的支持，这些表明：烟草上病毒积累水平以及症状的严重程度与GFP mRNA RNA沉默的抑制相关。
外文摘要：Cucumber green mottle mosaic virus (CGMMV), a tobamovirus, infects cucurbitaceous plants including watermelon. An attenuated strain of CGMMV (CGMMV-SH33b) has been isolated from CGMMV-SH and used for protecting muskmelon against wild CGMMV. There are five of nine base changes that lead to amino acid substitutions in the genome between SH and SH33b: four in replicase and one in coat protein. Using cDNA clones of both strains, two recombinant clones were constructed: first clone (pCG-KK) has two base changes (one silent at nt 5089 and the other P1397S amino acid substitution in the read-through part of SH 186K replicase) and the second clone (pCG-SP) has two silent base changes and three base changes in SH 129K/186K replicase (A1124V, N1157D and P1397S). The symptom severity on Nicotiana benthamiana induced by each recombinant virus were intermediate between those by SH and by SH33b. The accumulation levels of viruses using ELISA in infected plants were coinciding with symptom severity. Northern blot analysis of Nicotiana benthamiana at 10 dpi indicated that the virus accumulations of these recombinants was in the order of SH > pCG-KK > pCG-SP > SH33b. These results suggest that base changes located in the read-through part of 186K replicase as well as other base changes are responsible for the virus attenuation although we cannot excluded the possibility of silent mutations involved in pathogenicity. Using green fluorescent protein gene (GFP) silenced transgenic tobacco; infection with CGMMV-SH significantly suppressed GFP silencing with visible symptoms, whereas CGMMV-SH33b and their chimera viruses resulted in partial suppression. The suppression was further supported by lower level of GFP mRNA and higher siRNA detected in SH33b infected leaves, than those in CGMMV-SH infections, suggesting that the levels of virus accumulation and symptom severity on N. benthamiana were reasonably parallel with the suppression of RNA silencing of GFP mRNA.
 
外文关键词：Cucumber green mottle mosaic virus; Attenuated strain; cDNA clone; In vitro infectious cDNA; CGMMV; Suppression of RNA silencing
作者：Ali, Md Emran; Waliullah, Sumyya; Nishiguchi, Masamichi
作者单位：日本爱媛大学
期刊名称：JOURNAL OF PLANT BIOCHEMISTRY AND BIOTECHNOLOGY
期刊影响因子：1.352
出版年份：2016
出版刊次：1
点击下载：用于体外cDNA克隆的黄瓜绿斑驳花叶病毒弱毒株分子分析：RNA沉默的致病性与抑制