Wan Qun, Zhang Xing-Guo, Song Ming
Key Laboratory in Olericulture of Chongqing, College of Horticulture and Landscape, Southwest University, Chongqing 400716, China.
Sheng Wu Gong Cheng Xue Bao. 2007 May;23(3):429-33. doi: 10.1016/s1872-2075(07)60034-x.
Tomatoes ( Lycopersicon esculentum Mill.) are the principal dietary source of Lycopene which is one of carotenoid and is highly beneficial in preventing some diseases such as the cancer and the heart disease. Suppressing the expression of Lcy gene, the main gene regulating the transformation of the lycopene, is a convenient and effective way to enhance the content of lycopene. The primers were designed according to the gene sequence(U46919)and (X86452) in GenBank. The fruit-specific promoter--phytoene desaturase gene(Pds) promoter and the DNA segment of the Lcy gene were isolated from the genome DNA of tomatoes. The 3'end of Lcy DNA segment was connected together by an intron to inform the RNA interferential segment then which was inserted in the expression vector with the Pds promoter to inform the fruit-specific expression vector. The vector was transformed into the tomatoes through the Agrobacterium tumefaciens. Five transformants were obtained. And the PCR proved that the extra-gene was integrated into the tomato genome. The lycopene in the transgenic tomatoes fruit was increased significantly through analysing the contents of lycopene. These results show that regutating biosynthetic enzyme in carotenoid pathway by RNAi can improve the lycopene content of plant-derived products.
番茄（Lycopersicon esculentum Mill.）是番茄红素的主要膳食来源，番茄红素是类胡萝卜素之一，对预防某些疾病如癌症和心脏病非常有益。抑制番茄红素转化的主要调控基因Lcy基因的表达，是提高番茄红素含量的一种便捷有效的方法。根据GenBank中的基因序列（U46919）和（X86452）设计引物。从番茄基因组DNA中分离出果实特异性启动子——八氢番茄红素去饱和酶基因（Pds）启动子和Lcy基因的DNA片段。Lcy DNA片段的3'端通过一个内含子连接在一起形成RNA干扰片段，然后将其插入带有Pds启动子的表达载体中形成果实特异性表达载体。通过根癌农杆菌将该载体转化到番茄中。获得了5个转化体。PCR证明外源基因已整合到番茄基因组中。通过分析番茄红素的含量发现，转基因番茄果实中的番茄红素显著增加。这些结果表明，通过RNA干扰调控类胡萝卜素途径中的生物合成酶可以提高植物源产品中的番茄红素含量。
