Construction of Transgenic Resistance against Lisianthus necrosis virus

• Main Authors: Yu-Wei Lin, 林郁瑋
• Other Authors: Yuh-Kun Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/13880408329204053909

碩士 === 中興大學 === 植物病理學系所 === 103 === Lisianthus (Eustoma russellianum (Don.) Griseb) is an important ornamental crop in the cut flower industry worldwide. However, there are several viral diseases interfere lisianthus production in Taiwan, especially Lisianthus necrosis virus (LNV), which is probably the most devastating one to lisianthus. There were many approaches, including conventional resistance breeding and transgenic resistance, have been developed to build resistance in plants against viral diseases. Compared to the time-consuming conventional resistance breeding, transgenic approaches can provide more stable and specific resistance efficiency. In this study, in order to provide lisianthus with virus resistance, the effective strategy of post-transcriptional gene silencing (PTGS) was chosen. Based on previous researches, transgenic plants harboring viral sequences, both in sense or in anti-sense orientations, can trigger the formation of siRNA and thus lead to PTGS. These have been demonstrated successfully in several crops. Among these, the approach of using inverted-repeat (IR) constructs has been shown to have better efficacy. The cDNA fragments derived from LNV genes of RNA-dependent RNA polymerase (RdRp), coat protein (CP) and movement protein (MP) were separately cloned into the binary vector pBIN in the form of IR and already introduced into Nicotiana benthamiana and Eustoma russellianum by Agrobacterium tumefaciens-mediated transformation (ATMT) to generate transgenic tobacco and lisianthus potentially resistant to LNV. All four IR constructs, i.e. pLNVRD5-IR, pLNVRD3-IR, pLNV3’CP-IR, and pLNVMP-IR, conferred transgenic resistance to tobacco plants and the pLNVRD5-IR conferred the best efficiency among the four constructs. The resistance ratio in R0 tobacco of constructs pLNVRD5-IR, pLNVRD3-IR, pLNV3’CP-IR and pLNVMP-IR are 80.1%, 32%, 41.2% and 12.5%, respectively. The transformation and regeneration of lisianthus are now under processing. However, due to the limitation of growth rate of tissue-cultured lisianthus, the transgenic resistance of these transformants have not been analyzed yet.