Goo Young-Min, Han Eun-Heui, Jeong Jae Cheol, Kwak Sang-Soo, Yu Jaeju, Kim Yun-Hee, Ahn Mi-Jeong, Lee Shin-Woo
Sancheong Oriental Medicinal Herb Institute, Sancheong, Gyeongnam Province, Republic of Korea.
Department of Agronomy & Medicinal Plant Resources, Gyeongnam National University of Science & Technology, JinJu, Republic of Korea.
C R Biol. 2015 Jan;338(1):12-20. doi: 10.1016/j.crvi.2014.10.006. Epub 2014 Nov 13.
In a previous study, we have evidenced that the overexpression of the IbOr gene isolated from sweet potato conferred a tolerance activity against salinity and methyl viologen (MV) treatment in transgenic sweet potato calli along with an enhanced carotenoid content. In this study, to further examine the function of the IbOr gene in heterologous organism, we transformed the IbOr gene into potato under the direction of SWPA2 promoter, a strong inducible promoter upon treatment with various environmental stresses. Consistently with our previous study of sweet potato calli, the level of total carotenoid was elevated up to 2.7-fold (38.1 μg g(-1)DW) compared to the non-transgenic control, Atlantic cultivar. However, the composition of carotenoid was not influenced by the overexpression of the IbOr gene since only pre-existing carotenoids in the non-transgenic control including violaxanthin, lutien and β-carotene were elevated at a similar level of total carotenoids. In general, the transcript levels for most of carotenogenesis-related genes were elevated in transgenic tuber, whereas they remained at similar levels in transgenic leaf tissues compared to those of non-transgenic controls. The increased levels of carotenoid content in the leaf or tuber tissue of transgenic lines were correlated with the enhanced tolerance activity against salt- or MV-mediated oxidative stresses and DPPH radical-scavenging activity. Our preliminary results suggest that further investigation is required for the development of a crop tolerant to salinity and other environmental stresses through the overexpression of the IbOr gene.
在之前的一项研究中，我们已证明从甘薯中分离出的IbOr基因的过表达赋予了转基因甘薯愈伤组织对盐胁迫和甲基紫精（MV）处理的耐受活性，同时类胡萝卜素含量增加。在本研究中，为了进一步研究IbOr基因在异源生物体中的功能，我们在SWPA2启动子（一种在各种环境胁迫处理下具有强诱导性的启动子）的指导下，将IbOr基因转入马铃薯。与我们之前对甘薯愈伤组织的研究一致，与非转基因对照大西洋品种相比，总类胡萝卜素水平提高了2.7倍（38.1μg g(-1)DW）。然而，类胡萝卜素的组成不受IbOr基因过表达的影响，因为在非转基因对照中预先存在的类胡萝卜素（包括紫黄质、叶黄素和β-胡萝卜素）在总类胡萝卜素水平相似的情况下升高。一般来说，大多数类胡萝卜素合成相关基因的转录水平在转基因块茎中升高，而与非转基因对照相比，它们在转基因叶片组织中保持相似水平。转基因株系叶片或块茎组织中类胡萝卜素含量的增加与对盐或MV介导的氧化胁迫的耐受活性增强以及DPPH自由基清除活性相关。我们的初步结果表明，需要进一步研究通过IbOr基因的过表达来培育耐盐和其他环境胁迫的作物。
