Gupta Dipinte, Singh Oinam Washington, Basavaraj Y B, Roy Anirban, Mukherjee Sunil Kumar, Mandal Bikash
Division of Plant Pathology, Advanced Centre for Plant Virology, Indian Agricultural Research Institute, New Delhi, India.
Front Plant Sci. 2021 Dec 7;12:734618. doi: 10.3389/fpls.2021.734618. eCollection 2021.
Groundnut bud necrosis virus (GBNV) is the most significant member of the genus occurring in the Indian subcontinent. There is hardly any effective measure to prevent GBNV in crop plants. In order to develop GBNV infection prevention procedure, we examined the effect of the direct foliar application of double-stranded RNA (dsRNA) derived from the full-length gene (1,320 nucleotides) of GBNV. The bacterially expressed dsRNA to the non-structural (dsNSs) gene of GBNV was purified and delivered to plants as an aqueous suspension containing 0.01% Celite for evaluating its efficacy in preventing GBNV infection in systemic host, as well as in local lesion and systemic host, cowpea cv. Pusa Komal (). The dsNSs application and challenge-inoculation were conducted in three different combinations, where plants were challenge-inoculated with GBNV a day after, immediately, and a day before the application of dsNSs. plants, which were not treated with dsRNA showed severe systemic wilting and death by 9-16 days post-inoculation (dpi). The non-treated cowpea plants exhibited many chlorotic and necrotic lesions on the cotyledonary leaves followed by systemic necrosis and death of the plants by 14-16 dpi. The dsNSs treated plants in all the combinations showed significant reduction of disease severity index in both and cowpea. The treatment combination where the GBNV inoculation was conducted immediately after the dsNSs treatment was found to be the most effective treatment in preventing symptom expression. The viral RNA analysis by real time PCR also showed 20 and 12.5 fold reduction of GBNV in cowpea and , respectively. Our results suggest that the foliar application of dsRNA derived from the full-length gene of GBNV through Celite is successful in delivering long dsRNA leading to effective prevention of GBNV infection.
花生芽坏死病毒（GBNV）是印度次大陆出现的该属最重要的成员。在农作物中几乎没有任何有效的措施来预防GBNV。为了开发GBNV感染预防程序，我们研究了直接叶面喷施源自GBNV全长基因（1320个核苷酸）的双链RNA（dsRNA）的效果。将细菌表达的GBNV非结构（dsNSs）基因的dsRNA纯化，并作为含有0.01%硅藻土的水悬浮液施用于植物，以评估其在系统性宿主以及局部病斑和系统性宿主豇豆品种Pusa Komal中预防GBNV感染的功效。dsNSs的施用和挑战接种以三种不同组合进行，其中在施用dsNSs后的一天、立即和前一天用GBNV对植物进行挑战接种。未用dsRNA处理的植物在接种后9 - 16天出现严重的系统性萎蔫和死亡。未处理的豇豆植株在子叶上出现许多黄化和坏死病斑，随后在14 - 16天接种后天出现系统性坏死和植株死亡。所有组合中用dsNSs处理的植物在烟草和豇豆中疾病严重程度指数均显著降低。发现dsNSs处理后立即进行GBNV接种的处理组合在预防症状表达方面是最有效的处理方法。通过实时PCR进行的病毒RNA分析还显示，豇豆和烟草中GBNV分别减少了20倍和12.5倍。我们的结果表明，通过硅藻土叶面喷施源自GBNV全长基因的dsRNA成功地递送了长dsRNA，从而有效预防了GBNV感染。
