Researchers from Tel Aviv University explored a way to grow tomato varieties while using less water, without sacrificing yield, fruit quality, or taste. They used CRISPR gene editing to help crops endure drier, water-scarce conditions, a topic of growing importance for farming in arid regions and areas facing climate pressures. This work appears in the Proceedings of the National Academy of Sciences (PNAS), highlighting potential improvements for tomato cultivation and water management that could benefit farmers in North America as well as around the world. The study emphasizes that while water efficiency is crucial, maintaining fruit quantity and flavor remains essential for commercial viability and consumer satisfaction (citation: Tel Aviv University, PNAS).
In drought scenarios, plants naturally limit water loss by closing stomata, tiny openings on leaf surfaces that also regulate carbon dioxide intake for photosynthesis. When stomata close to save water, carbon dioxide uptake decreases, which can slow sugar production and hinder growth. This trade-off often results in smaller or softer fruits with reduced sweetness and nutritional value, impacting both harvest yield and quality. The researchers’ findings point to a genetic approach that can help plants manage water use while keeping photosynthesis viable and crops productive (citation: plant physiology context, TAU study).
Stomata play a pivotal role in balancing water transpiration with gas exchange. Their behavior is influenced by many factors, including time of day and environmental conditions. The work notes that stomata tend to be more open when transpiration demand is lower, such as in the morning and late afternoon, which allows some carbon dioxide to enter and supports continued sugar production even as water loss is kept in check during peak heat. This nuanced regulation is central to improving water-use efficiency without sacrificing crop performance (citation: stomatal biology overview).
The study highlights a concrete genetic modification aimed at optimising stomatal behavior. By editing a gene known as ROP9, researchers observed partial stomatal closure at the hottest time of day, when water loss would otherwise be most rapid. Importantly, this partial closure did not prevent carbon dioxide from entering the leaves during the critical periods when photosynthesis is most active. In morning and afternoon hours, when stomata normally open more widely, the modified plants still absorbed enough CO2 to sustain sugar production, supporting steady growth and fruit development (citation: TAU CRISPR ROP9 findings).
To verify real-world impact, the team carried out extensive field trials with hundreds of tomato plants under realistic growing conditions. The results showed that plants with the ROP9 modification consumed less water through transpiration while maintaining comparable photosynthesis, sugar production, and harvest quality to unmodified plants. No negative effects on fruit sugar content or overall yield were observed. The researchers also identified an unexpected mechanism that further governs stomatal dynamics, offering new avenues for enhancing water use efficiency across crops beyond tomatoes (citation: field trial results, TAU study).
These advances suggest that genetic editing could revolutionize agricultural practices by enabling crops to conserve water without compromising productivity or fruit quality. The work also draws parallels with similar genes found in other cultivated species such as peppers, eggplants, and wheat, implying that the insights gained from tomato biology may translate to a broader range of crops. If further studies confirm these effects, the approach could form a foundation for improving water use efficiency in multiple crops, supporting farmers in Canada and the United States as they adapt to changing water availability (citation: cross-crop implications, TAU researchers).
Overall, the study offers both a practical strategy to reduce irrigation demands and a deeper understanding of stomatal regulation and plant metabolism. It points to a future where crops can better balance water use with carbon gain, sustaining productivity in warmer climates and drier seasons. The findings open doors to additional research on how ROP9-like pathways interact with other regulators of stomatal movement, with the potential to extend benefits to a wider array of staple crops used by North American growers (citation: broader impact discussion, TAU).
Reference work: TAU researchers and collaborators, PNAS logic and data from the cited study.
Note: This summary consolidates the reported results, without direct links, and attributes key claims to the original publication and participating researchers.