Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, West Bengal, India.
Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India.
Sci Rep. 2017 Aug 11;7(1):7900. doi: 10.1038/s41598-017-08180-x.
Sheath blight, caused by the necrotrophic fungal pathogen Rhizoctonia solani, is a serious and destructive disease of the rice. In order to improve sheath blight resistance, we developed three different kinds of transgenic rice lines. The first transgenic line overexpresses the rice chitinase gene (OsCHI11); the second contains the Arabidopsis NPR1 (AtNPR1) gene and, the third has pyramided constructs with both the genes (OsCHI11 and AtNPR1). This is a comparative study between the single-gene transgenic lines and the double gene transgenic in terms of their ability to activate the plant defense system. Rice plants of each individual construct were screened via PCR, Southern hybridization, activity assays, and expression analysis. The best transgenic lines of each construct were chosen for comparative study. The fold change in qRT-PCR and activity assays revealed that the pyramided transgenic rice plants show a significant upregulation of defense-related genes, PR genes, and antioxidant marker genes as compared to the single transgene. Simultaneous co-expression of both the genes was found to be more efficient in tolerating oxidative stress. In R. solani (RS) toxin assay, mycelial agar disc bioassay, and in vivo plant bioassay, pyramided transgenic plant lines were more competent at restricting the pathogen development and enhancing sheath blight tolerance as compared to single gene transformants.
鞘腐病是由坏死型真菌病原菌立枯丝核菌引起的，是一种严重且具破坏性的水稻病害。为了提高对鞘腐病的抗性，我们开发了三种不同的转基因水稻品系。第一种转基因品系过量表达水稻几丁质酶基因（OsCHI11）；第二种含有拟南芥 NPR1（AtNPR1）基因，第三种则含有这两个基因的嵌合构建体（OsCHI11 和 AtNPR1）。本研究比较了单基因转基因品系和双基因转基因品系在激活植物防御系统方面的能力。通过 PCR、Southern 杂交、活性测定和表达分析对每个个体构建体的水稻植株进行筛选。选择每个构建体的最佳转基因系进行比较研究。qRT-PCR 和活性测定的倍数变化表明，与单转基因相比，嵌合转基因水稻植株中与防御相关的基因、PR 基因和抗氧化标记基因的表达显著上调。同时表达这两个基因被发现更有效地耐受氧化应激。在立枯丝核菌（RS）毒素测定、菌丝丝琼脂盘生物测定和体内植物生物测定中，与单基因转化体相比，嵌合转基因植物品系更能限制病原菌的发展并提高对鞘腐病的耐受性。
