Chiab Nour, Kammoun Mariem, Nouri-Ellouz Oumèma, Gargouri-Bouzid Radhia
Plant amelioration and Agri-resources valorization laboratory, National Engineering School of Sfax (ENIS), Soukra Road Km 4, 3038, Sfax, Tunisia.
Plant amelioration and Agri-resources valorization laboratory, National Engineering School of Sfax (ENIS), Soukra Road Km 4, 3038, Sfax, Tunisia.
J Plant Physiol. 2023 Oct;289:154077. doi: 10.1016/j.jplph.2023.154077. Epub 2023 Aug 25.
In a previous study, transgenic potato plants overexpressing the StDREB1 or the VvWRKY2 transcription factor (TF) proved to have higher productivity and ameliorated tuber quality in comparison to wildtype (WT; the BF15 variety) plants. Interestingly, when stored at 4 °C, we noticed that the tubers of transgenic potato plants exhibited a delay in sprouting, hence a longer dormancy period. Therefore, we decided to study the dormancy and sprouting of these tubers (the two transgenic and the WT lines) through a physiological and biochemical characterization. WT and genetically modified (GM) tubers were stored at 4 °C for different periods (0, 30, 90, 180, and 240 days) followed by placing them in a germination chamber and the sprouting parameters were then monitored. According to our findings, the overexpression of these two TFs led to modifications in the sprouting kinetic of tubers through an extension of the dormancy period and changes in the sprouting process. Indeed, WT tubers emitted apical and lateral sprouts while those from GM plants showed mainly apical sprouts. In addition, higher reactive oxygen species (ROS) rates, indicators of tuber aging, were recorded in WT tubers compared to GM ones. The higher antioxidant enzyme activities in GM tubers seem to be responsible for aging modification in comparison to WT. The above results suggest the first report on new roles of the StDREB1 and VvWRKY2 TF which seemed to be involved in the regulation of potato tuber aging via a reduction of the main biochemical factors concentration and the ROS content leading to a longer dormancy period and a modified sprouting pattern.
在之前的一项研究中，与野生型（WT；BF15品种）植株相比，过表达StDREB1或VvWRKY2转录因子（TF）的转基因马铃薯植株表现出更高的生产力和改良的块茎品质。有趣的是，当在4℃下储存时，我们注意到转基因马铃薯植株的块茎发芽延迟，因此休眠期更长。因此，我们决定通过生理生化特征研究这些块茎（两个转基因株系和野生型株系）的休眠和发芽情况。将野生型和转基因（GM）块茎在4℃下储存不同时间（0、30、90、180和240天），然后将它们置于发芽室中，随后监测发芽参数。根据我们的研究结果，这两种转录因子的过表达通过延长休眠期和改变发芽过程导致块茎发芽动力学发生改变。实际上，野生型块茎发出顶芽和侧芽，而转基因植株的块茎主要发出顶芽。此外，与转基因块茎相比，野生型块茎中记录到更高的活性氧（ROS）速率，这是块茎衰老的指标。与野生型相比，转基因块茎中较高的抗氧化酶活性似乎是导致衰老改变的原因。上述结果首次报道了StDREB1和VvWRKY2转录因子的新作用，它们似乎通过降低主要生化因子浓度和ROS含量参与马铃薯块茎衰老的调控，从而导致更长的休眠期和改变的发芽模式。
