Choi Hye Lim, Seo Ji Won, Hwang Myeong Ha, Yu Chang Yeon, Seong Eun Soo
Department of Bio-Resource Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea.
Interdisciplinary Program in Smart Science, Kangwon National University, Chuncheon, 2434, Republic of Korea.
Transgenic Res. 2022 Jun;31(3):381-389. doi: 10.1007/s11248-022-00307-9. Epub 2022 Apr 24.
The SAMS (S-adenosylmethionine synthetase) gene is known to play an important role in the mechanism of cold resistance, as overexpression of this gene results in phenotypic changes in T-generation transgenic plants. Accordingly, this study was conducted to test the expression of the MsSAMS gene in T-generation transgenic plants and to investigate the resistance of these plants and the function of the transgene in response to various environmental stresses. For the morphological analysis of T-generation transgenic plants overexpressing the MsSAMS gene, observations using scanning electron microscopy (SEM) were performed. T-generation transgenic plants were obtained by planting a total of 5 lines, and their characteristics were tested by comparisons with those of the control. SEM revealed that the thickest leaves were produced by the T6 transgenic line-161.24 ± 8.05 µm. The number of stomata ranged from 20.00 ± 2.65 to 34.00 ± 1.00 in the T-generation transgenic plants, but the control had more stomata. Resistance to various factors, such as low temperature, drought, and oxidative stress, in the T-generation transgenic plants was also confirmed. Under cold-stress conditions, the T6 transgenic line presented the lowest value (22.73%) of ion leakage, and under drought-stress conditions, compared with the control, the transgenic lines presented lower ion leakage after being treated with various concentrations of mannitol. Even under oxidative-stress conditions, the T-generation transgenic plants presented ion leakage levels that were 32.91 ± 4.24 to 48.33 ± 3.54% lower than those of the control after treatment with various concentrations of methyl viologen. Regarding SAMS enzyme activity, as the duration of cold treatment increased, the activity in the transgenic plants tended to decrease and then increase. During 48 h of cold treatment, the control showed a decrease in SAM content, while the T-generation transgenic plants presented an increase in SAM content, from 13.58 ± 1.04 to 22.75 ± 1.95 mg protein/g FW. The results suggest that the MsSAMS gene may be important to the mechanisms of resistance to oxidative and drought stresses in addition to its previously known association with cold resistance. Based on these results, it was suggested that the MsSAMS gene, whose expression is induced by cold stress, can serve as a marker of various responses to environmental stresses, because resistance to cold damage and various environmental stresses are stably inherited in the T generation.
已知SAMS（S-腺苷甲硫氨酸合成酶）基因在抗寒机制中发挥重要作用，因为该基因的过表达会导致T代转基因植物出现表型变化。因此，本研究旨在检测MsSAMS基因在T代转基因植物中的表达，并研究这些植物的抗性以及转基因在应对各种环境胁迫时的功能。为了对过表达MsSAMS基因的T代转基因植物进行形态学分析，使用扫描电子显微镜（SEM）进行了观察。通过种植总共5个株系获得了T代转基因植物，并通过与对照进行比较来测试它们的特性。SEM显示，T6转基因株系-161产生的叶片最厚，为161.24±8.05μm。T代转基因植物的气孔数量在20.00±2.65至34.00±1.00之间，但对照的气孔更多。还证实了T代转基因植物对低温、干旱和氧化胁迫等各种因素具有抗性。在冷胁迫条件下，T6转基因株系的离子渗漏率最低（22.73%），在干旱胁迫条件下，与对照相比，转基因株系在用不同浓度甘露醇处理后离子渗漏率更低。即使在氧化胁迫条件下，T代转基因植物在用不同浓度甲基紫精处理后的离子渗漏水平也比对照低32.91±4.24%至48.33±3.54%。关于SAMS酶活性，随着冷处理时间的增加，转基因植物中的活性先下降后上升。在48小时的冷处理期间，对照的SAM含量下降，而T代转基因植物的SAM含量增加，从13.58±1.04增加到22.75±1.95mg蛋白/g鲜重。结果表明，MsSAMS基因除了其先前已知的与抗寒相关外，可能对氧化和干旱胁迫抗性机制也很重要。基于这些结果，有人提出，其表达受冷胁迫诱导的MsSAMS基因可作为对各种环境胁迫反应的标志物，因为对冷害和各种环境胁迫的抗性在T代中稳定遗传。
