The excessive use of nitrogen fertilizers has become a double-edged sword in agriculture, driving high yields but leaving behind a legacy of environmental damage. Less than half of the nitrogen applied is absorbed by crops, with the remainder leaching into the soil and water systems, degrading their quality. Nitrate stress disrupts plant growth by overloading cells with reactive oxygen species (ROS), leading to oxidative damage. Faced with these challenges, scientists are increasingly focusing on the molecular responses of plants to develop solutions that mitigate the adverse effects of nitrate stress.
On July 10, 2024, researchers from kunming university of science and technology, in collaboration with international experts, unveiled their findings (DOI: 10.1093/hr/uhae184) in Horticulture Research. Their study explores how the sltrxh protein, regulated by the transcription factor slmyb86, acts as a molecular shield against nitrate-induced stress in tomatoes. By boosting the expression of sltrxh, they found that oxidative damage was significantly reduced while the activity of antioxidant enzymes was enhanced. This discovery provides a molecular foundation for developing stress-resilient crop varieties.
The research offers a detailed understanding of how tomatoes counteract nitrate stress at the cellular level. Sltrxh is activated by slmyb86, a transcription factor that binds to its promoter region. Under nitrate stress, sltrxh undergoes s-nitrosation—a chemical modification at the critical cysteine 54 site—which enhances its antioxidant capabilities. This modification also strengthens the interaction between sltrxh and slgrx9, another protein involved in mitigating stress. These synergistic actions collectively enable the plant to maintain lower ROS levels and protect against cellular damage.
Transgenic experiments provided compelling evidence: Tomato plants with overexpressed sltrxh showed robust growth, longer roots, and reduced oxidative stress under nitrate overload. In contrast, plants where sltrxh expression was suppressed displayed stunted growth, higher ros levels, and greater damage. These results underscore the critical role of sltrxh in conferring nitrate stress tolerance.
Dr. Huini xu, who spearheaded the research, stressed the transformative potential of these findings: "This study sheds light on the intricate molecular pathways plants use to adapt to environmental stresses. By harnessing the regulatory interplay of proteins like sltrxh and transcription factors such as slmyb86, we can advance crop engineering to create plants that are more resilient to the pressures of modern agriculture."
The implications of this research extend far beyond tomatoes. With global food demands rising, the development of crops that can endure environmental stresses is a pressing need. By targeting sltrxh and slmyb86 through genetic engineering or selective breeding, agricultural scientists can design crops that thrive in challenging conditions. This could lead to higher yields, improved quality, and reduced reliance on nitrogen fertilizers, fostering a more sustainable approach to farming. Such innovations promise to mitigate the environmental impact of nitrate pollution while ensuring food security for a growing population.
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References
DOI
10.1093/hr/uhae184
Original Source URL
https://doi.org/10.1093/hr/uhae184
Funding information
This research was funded by the National Natural Science Foundation of China (Grant Nos. 32260753, 31760582) and the Yunnan Ten Thousand Talents Plan: Young & Elite Talents Project.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2022. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.