Kumar G, Jyothsna M, Valarmathi P, Roy S, Banerjee A, Tarafdar J, Senapati B K, Robin S, Manonmani S, Rabindran R, Dasgupta I
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India.
Department of Rice, Tamil Nadu Agricultural University, Coimbatore, 641003, India.
Arch Virol. 2019 Apr;164(4):1005-1013. doi: 10.1007/s00705-019-04159-3. Epub 2019 Feb 8.
Rice crops in South and Southeast Asian countries suffer critical yield losses due to rice tungro disease caused by joint infection with rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). Previously, for generating RNA interference-based transgenic resistance against tungro viruses, RTBV ORF IV was used as a transgene to develop RTBV resistance in a popular high-yielding scented rice variety. The transgene from this line was then introgressed into five popular high-yielding but tungro-susceptible rice varieties by marker-assisted backcross breeding with a view to combine the resistant trait with the agronomic traits. The present work includes a resistance assay of the BCF lines of these varieties under glasshouse conditions. Out of a total of 28 lines tested, each consisting of 12 individual plants, eight lines showed significant amelioration in height reduction and 100- to 1000-fold reduction in RTBV titers. The RNAi-mediated resistance was clearly manifested by the presence of virus-derived small RNA (vsRNA) specific for RTBV ORF IV in the transgenic backcrossed lines.
南亚和东南亚国家的水稻作物因感染水稻东格鲁杆状病毒（RTBV）和水稻东格鲁球状病毒（RTSV）而遭受严重的产量损失。此前，为了培育基于RNA干扰的抗东格鲁病毒转基因水稻，RTBV开放阅读框IV被用作转基因，在一个广受欢迎的高产香稻品种中培育对RTBV的抗性。然后，通过标记辅助回交育种，将该品系的转基因导入五个高产但易感东格鲁病的水稻品种中，以期将抗性性状与农艺性状相结合。目前的工作包括在温室条件下对这些品种的回交后代（BCF）品系进行抗性检测。在总共测试的28个品系中，每个品系由12株单株组成，其中8个品系在株高降低方面有显著改善，RTBV滴度降低了100至1000倍。转基因回交品系中存在针对RTBV开放阅读框IV的病毒衍生小RNA（vsRNA），这清楚地表明了RNAi介导的抗性。
