Plant Stress Physiology
Addressing increasing challenges to crop plants
Our research on the environmental stress physiology of plants includes the physiological, biochemical and molecular mechanisms and other traits that confer tolerance to environmental stresses. In Weslaco, our research focuses especially on drought, temperature extremes and nutrient imbalance.
A key theme of this research is integrating measurements obtained at leaf, whole-plant and stand levels to study factors that regulate photosynthetic efficiency, water and nutrient use efficiency, assimilate partitioning, yield and quality. Our aim is to use the information gained in these studies to develop practical strategies to optimize plant productivity and quality by improving plant tolerance to environmental stresses.
Program faculty and staff
John Jifon
Professor
Interests
- Phenotyping of physiological traits for abiotic stress tolerance and quality
- Impacts of rising atmospheric carbon dioxide concentration on crop productivity and quality
- On-farm strategies to mitigate impacts of abiotic stress factors.
- Pre-harvest food fortification strategies to promote food/nutritional security
- Resource optimization, source-sink relationships and crop load effects on yield and quality
- New/improve crops to support the bioeconomy, improve soil health and carbon sequestration
Publications
A full selection of Dr. Jifon’s publications is available at TAMU Scholars along with information about researchers and peer-reviewed publications across The Texas A&M University System.
Recent Research
Current Research areas include: pre-harvest approaches to enhance functional quality of fruits and vegetables; resource-efficient systems for production of nutrient-dense foods; climate-smart crops/cropping systems to mitigate stress impacts on productivity and food quality. We use a transdisciplinary approach integrating/addressing processes at multiple levels of organization (e.g., whole-plant/stand levels, as well as leaf-level physiological, morphological, biochemical, molecular/genetic traits and processes) to better understand and predict how plants function under the constraints of complex and dynamic environments. Techniques include standard ecophysiological characterizations, as well as remote sensing, and high-throughput phenotyping tools (e.g., NIR spectroscopy, etc.) to extract valuable biological information to facilitate decision-making processes for crop management. The ultimate practical goal is to promote sustainability, profitability, and economic viability of the produce industry.
Current Projects
Integrated Management of Environmental Stresses: Environmental conditions are seldom ideal for plant growth in both managed and natural ecosystems. Biotic and abiotic stresses collectively reduce crop productivity by over 75% compared to potential yields (Boyer 1982). Individual stressors such as drought, salinity or heat have been the subject of intense research. However, under field conditions, crops are often subjected to a combination of different stresses. Understanding how plants respond to, and tolerate these stresses is crucial for crop improvement and development of resilient production systems. Our approach focuses on symptoms, responses and tolerance mechanisms/traits that are common to multiple stress factors as part of an effort to develop integrated strategies for multiple stress management. We are particularly interested in oxidative stress (OS) and generation of reactive oxygen species (ROS) as a common response to stress exposure. The array of antioxidant (AOs) mechanisms to prevent formation of ROS or to scavenge ROS constitute a unifying response/tolerance mechanism. Cultivars with elevated levels of these AOs seem to tolerate stresses better and plant-based diets rich in AOs (especially fruits/vegetables) also seem to protect humans from diet-related ailments such as eye and heart diseases, and certain cancers) that have been linked to enhanced oxidative stress. Related Grants: Crosby, K., Jifon J. et al. (2021-2023) Enhancing pepper production, profitability and seed in the southwest U.S. USDA- Specialty Crop Multi-State Program (SCMP); Arpaia, M.L., et al. (2019-2024) Adapting avocados for commercial success in extreme environments to enhance US based avocado production. USDA-Agricultural Marketing Service – Specialty Crop Multi-State Program (SCMP); Manosalva, P., et al. (2021-2024) Reducing avocado losses to major challenges by improving resistance selection and disease management using next generation technologies. USDA-NIFA-CAP Specialty Crop Research Initiative.; Alabi, O, Jifon J, Isakeit T (2022-2024) Assessing the biodiversity of viruses infecting cucurbits in Texas and development of appropriate IPM-based virus disease management strategies Texas Dept. of Agric. – Specialty Crop Block Grant Program.
Nutrition physiology and nutrient management of horticultural crops. This project focuses on crop nutrient management for retail/sensory quality. Research addresses limitations to uptake, translocation, and utilization, and demand-supply relationship of key quality nutrients such as potassium (K) and calcium (Ca) in horticultural crops (melons, watermelons, onions, tomatoes, citrus, avocado, etc.). The 4R Nutrient management concept (Right nutrient source, at the Right rate, Right time and Right placement) provides a framework for these investigations that ensure increased production/quality, added value, increased farmer profitability, enhanced environmental protection and improved sustainability. We are also using these concepts for staple food fortification as an effective pre-harvest strategy to fight vitamin and mineral nutrient deficiency. Related Grants: Jifon, J, Crosby K (2021-2023) Improving quality and profitability of Texas pepper production with cropping strategies and novel Texas A&M genetics. Texas Dept. of Agric. – Specialty Crop Block Grant Program; Patil B, Crosby K, Jifon J (2022-2024) Developing Consumer-Friendly Mild Onions Using Nanotechnology and Improved Genetics. Texas Dept. of Agric. – Specialty Crop Block Grant Program; Patil B, et al. (2022-2024) Table to Farm: A sustainable, systems-based approach for a safer and healthier melon supply chain in the U.S. USDA-NIFA-SCRI-CAP; Crosby K, Jifon J, Patil B (2018-2024) New cultivars and production technologies to strengthen the cantaloupe industry. Texas Dept. of Agric. – Specialty Crop Block Grant Program
Controlled Environment Horticulture/Urban Agriculture using resource-efficient crops/cropping systems: More than 50% of the world’s population currently lives in cities and this proportion is expected to exceed 70% by 2050 (United Nations, 2019). This unprecedented population increase poses numerous challenges for agricultural production, food security as well as human health/wellbeing and local economies. An obvious challenge for agriculture is ensuring adequate production and timely supply of safe, affordable and nutritious foods to address caloric requirements and provide cost-effective solutions for malnutrition and other diet-related chronic disease problems. Our research in this area focuses on optimizing resource-efficient cropping systems namely, controlled environment production systems such as hydroponics, aquaponics, vertical farming, etc., for urban and peri-urban communities. The extremely high water, nutrient and land productivity of these systems make them ideal platforms for creating value-added products including precision nutrition foods. Related Grants: Racine E., et al., (2023-2028) The Southwest (New Mexico/Texas) Regional Food Business Center. USDA – Agriculture Marketing Service; Jifon, J., et al. (2021-2023) Avocado: An Ideal Specialty Crop to Add Value and Diversify the Texas Fruit Industry. Texas Dept. of Agric. – Specialty Crop Block Grant Program.
BioEnergy-Bioeconomy: Sustainable Ag production is key to the rapidly expanding bioeconomy (production and conversion of biomass into value-added products, such as food, feed, bio-based products, and bioenergy). Our research in this area involves screening and identification of high-yielding next-generation, low-input biomass crops that can serve as feedstocks for bio-based products and as well as offset greenhouse gas (GHG) emissions through carbon sequestration in harvested biomass and soil storage. Our research focuses on warm-season perennial/rhizomatous grasses (energy canes, biomass sorghums, etc.) that could become net-zero feedstocks for adding value to the emerging bioeconomy. Related Grants: Wilson L., et al., (2018-2024) Sustainable Herbaceous Energy Crop Production in the Southeast United States; DOE-Office of Energy Efficiency and Renewable Energy-EERE; Jifon et al. (2014-2023) A Water and Risk Management Tool for Sustainable Production of Bioenergy Feedstocks. USDA-NIFA.
