Engineering stress-tolerant crops
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: California leads the agricultural production of the country. There are over 7.5 million acres of crop land harvested in California annually. Approximately 75% of these acres are planted with field crops and vegetables, representing more than 100 species. Crop production in both the Imperial Valley and the San Joaquin Valley is highly diversified and they produce a significant portion of the total State production. Crop production depends on light, water, temperature, soil nutrients, etc. While light is usually not limiting, water, temperature and soil nutrient status are key elements for sustainable agriculture. Environmental stresses are the most serious factors limiting the productivity of agricultural crops. Abiotic stresses such as drought, heat, and salinity can have a devastating economic and sociological impact. The economic consequences of environmental stress on agricultural productivity are well documented with average costs in California of approximately 500 million dollars per year. Recent studies have linked the increased frequency of severe abiotic stress events with global warming, emphasizing the urgent need to develop crops with enhanced tolerance to abiotic stresses. This research proposal aims at the development of stress-tolerant crops able to tolerate the combination of stresses that occur in nature simultaneously (drought, heat, salinity), thus producing high yields under adverse environmental conditions. We have recently made significant progress in developing transgenic crop plants with a remarkable tolerance to severe drought stress. We characterized a number of molecular networks used by the transgenic plants for the adaptation to changing environments, and identified key genes that could be used to engineer crop plants able to respond efficiently to a combination of the stresses typical to the field environment. Our working hypothesis, based on recent findings in our laboratory, is that the partitioning of assimilates and nutrients between source and sink tissues is the key factor in the adaptation of crop plants to adverse environmental conditions. We have identified a number of genes that regulate hormone homeostasis and alter the source/sink balance during stress. These hormonal transitions play major roles in the ability of the transgenic plants to delay their stress response, resulting in enhanced stress tolerance and increased grain yields. We will focus our work on cereals, using rice, and the cereal model plant Brachypodium, and the legume alfalfa. We will use a systems approach combining plant transformation, genomics, proteomics, and metabolomics to understand and engineer multi-tolerance traits. Our specific objectives are, to modify hormonal homeostasis (modifying endogenous levels of cytokinins and brassinosteroids) and, to introduce regulatory mechanisms for starch biosynthesis and antioxidant production recently discovered in our laboratory to develop stress-resistant crops.