In a significant stride towards developing drought-resistant crops, researchers have successfully enhanced tobacco plants’ tolerance to drought by introducing a gene from milk thistle. The study, led by Rahele Ghanbari Moheb Seraj from the University of Mohaghegh Ardabili, was recently published in *Scientific Reports*.
The research focuses on the superoxide dismutase (SOD) gene, a crucial component in plants’ defense mechanism against reactive oxygen species (ROS). By transferring the SOD gene from milk thistle (Silybum marianum L.) to tobacco plants, the team aimed to improve the latter’s resilience to drought conditions.
The results were promising. Transgenic tobacco plants expressing the milk thistle SOD gene showed a fivefold increase in SOD expression and nearly double the enzyme activity compared to wild-type plants under drought stress. “The enhanced expression of SOD in transgenic plants helped maintain a better balance of ROS, which is vital for protecting cells from damage,” Seraj explained.
One of the most striking findings was the improvement in photosynthetic efficiency. Imaging of chlorophyll fluorescence revealed that transgenic plants had a higher maximum quantum yield of photosystem II (Fv/Fm) and non-photochemical quenching (NPQ) compared to wild-type plants. This suggests that the transgenic plants were better equipped to handle drought stress by optimizing their photosynthetic processes.
The study also examined stomatal characteristics. Stomatal density decreased under drought conditions in both transgenic and wild-type plants, but the width of stomata was significantly smaller in transgenic plants. This adaptation likely contributes to the plants’ ability to conserve water during drought.
The implications for agriculture are substantial. As water scarcity becomes an increasingly pressing issue, developing crops that can thrive in arid conditions is crucial. “This research sheds light on the path toward reaching drought-tolerant crops,” Seraj noted. “The findings highlight the potential of the SmSOD gene as a key player in improving drought resistance in various crops.”
The commercial impact could be profound, particularly in regions where water is a limited resource. By incorporating the SmSOD gene into other commercially important crops, farmers could potentially increase yields and reduce water usage, leading to more sustainable and resilient agricultural practices.
This research not only advances our understanding of plant stress tolerance mechanisms but also opens new avenues for genetic engineering in agriculture. As the global population grows and climate change intensifies, the need for drought-resistant crops becomes ever more urgent. The work of Seraj and her team represents a significant step forward in addressing these challenges, offering hope for a more food-secure future.