Researchers at Tel Aviv University have achieved a groundbreaking feat by cultivating and characterizing tomato varieties with increased water use efficiency, all without compromising yield. Leveraging the CRISPR genetic editing technology, the team managed to grow tomatoes that not only consume less water but also maintain high yield, quality, and taste. The study, led by Prof. Shaul Yalovsky and Dr. Nir Sade from the School of Plant Sciences and Food Security at Tel Aviv University’s Wise Faculty of Life Sciences, involved contributions from a diverse group of researchers, including collaborators from Ben Gurion University and the University of Oregon.

Published in the journal PNAS, the research addresses the pressing need for agricultural crops that thrive with reduced water consumption, given the challenges posed by global warming and dwindling freshwater resources. The study focuses on the intricate relationship between transpiration, where plants release water through their leaves, and the uptake of carbon dioxide, essential for photosynthesis.

Under drought conditions, plants respond by closing their stomata, specialized openings on leaf surfaces that regulate water status. However, the downside is a reduction in carbon dioxide uptake, leading to decreased sugar production through photosynthesis. This decline adversely affects plant growth, impacting both the quantity and quality of the harvest.

To tackle this issue, the researchers used CRISPR to target the ROP9 gene in tomatoes, a gene associated with stomatal regulation. The results showed that by eliminating ROP9, the stomata partially closed during midday, minimizing water loss during peak transpiration. Importantly, this closure did not hinder carbon dioxide uptake in the morning and afternoon, ensuring consistent sugar production through photosynthesis.

Extensive field experiments with hundreds of plants confirmed that the ROP9-modified tomatoes exhibited increased water efficiency without compromising photosynthesis, crop quantity, or quality. The study also uncovered an unexpected mechanism tied to the level of reactive oxygen species, providing new insights into stomatal opening and closing.

Prof. Yalovsky emphasized the significance of their findings, stating, “There is great similarity between the ROP9 in tomatoes and ROP proteins found in other crop plants. Therefore, the discoveries detailed in our article could form the basis for the development of additional crop plants with enhanced water use efficiency, and for a deeper understanding of the mechanisms behind stomatal opening and closing.” The research not only promises water-efficient tomatoes but opens the door to improving water use efficiency in various crop plants, contributing to sustainable agriculture.

By Impact Lab