Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, MARA Key Laboratory on Safety Assessment (Molecular) of Agri-GMO, 12 Zhuangguancun South Street, Beijing, 100081, China.
BMC Plant Biol. 2019 Aug 7;19(1):346. doi: 10.1186/s12870-019-1956-y.
The safety assessment and control of stacked transgenic crops is increasingly important due to continuous crop development and is urgently needed in China. The genetic stability of foreign genes and unintended effects are the primary problems encountered in safety assessment. Omics techniques are useful for addressing these problems. The stacked transgenic maize variety 12-5 × IE034, which has insect-resistant and glyphosate-tolerant traits, was developed via a breeding stack using 12-5 and IE034 as parents. Using 12-5 × IE034, its parents (12-5 and IE034), and different maize varieties as materials, we performed proteomic profiling, molecular characterization and a genetic stability analysis.
Our results showed that the copy number of foreign genes in 12-5 × IE034 is identical to that of its parents 12-5 and IE034. Foreign genes can be stably inherited over different generations. Proteomic profiling analysis found no newly expressed proteins in 12-5 × IE034, and the differences in protein expression between 12 and 5 × IE034 and its parents were within the range of variation of conventional maize varieties. The expression levels of key enzymes participating in the shikimic acid pathway which is related to glyphosate tolerance of 12-5 × IE034 were not significantly different from those of its parents or five conventional maize varieties, which indicated that without selective pressure by glyphosate, the introduced EPSPS synthase is not has a pronounced impact on the synthesis of aromatic amino acids in maize.
Stacked-trait development via conventional breeding did not have an impact on the genetic stability of T-DNA, and the impact of stacked breeding on the maize proteome was less significant than that of genotypic differences. The results of this study provide a theoretical basis for the development of a safety assessment approach for stacked-trait transgenic crops in China.
由于作物的不断发展，对堆叠转基因作物的安全性评估和控制变得越来越重要，这在中国是迫切需要的。外源基因的遗传稳定性和非预期效应是安全性评估中遇到的主要问题。组学技术可用于解决这些问题。堆叠转基因玉米品种 12-5×IE034 具有抗虫和抗草甘膦特性，是通过将 12-5 和 IE034 作为亲本进行育种堆叠开发的。使用 12-5×IE034、其亲本（12-5 和 IE034）和不同的玉米品种作为材料，我们进行了蛋白质组学分析、分子特征分析和遗传稳定性分析。
我们的结果表明，12-5×IE034 中外源基因的拷贝数与其亲本 12-5 和 IE034 相同。外源基因可以在不同世代中稳定遗传。蛋白质组学分析发现 12-5×IE034 中没有新表达的蛋白质，12-5×IE034 与其亲本之间的蛋白质表达差异在常规玉米品种的变异范围内。与草甘膦耐受性相关的莽草酸途径中关键酶的表达水平在 12-5×IE034 与其亲本或五个常规玉米品种之间没有显著差异，这表明在没有草甘膦选择压力的情况下，引入的 EPSPS 合酶对玉米中芳香族氨基酸的合成没有明显影响。
通过常规育种进行的叠加性状开发不会影响 T-DNA 的遗传稳定性，叠加育种对玉米蛋白质组的影响小于基因型差异的影响。本研究结果为中国发展叠加性状转基因作物的安全性评估方法提供了理论依据。
