Enhancing Abiotic Stress Response via a Kalanchoe fedtschenkoi NF‐Y Transcription Factor in C3 Plants

Global crop production is expected to decrease because of increasing abiotic stressors including extremes in temperature, water, light intensity, nutrients, and radiation due to climate change and anthropogenic activities. Increased abiotic stressors will alter the metabolism in C 3 plants and thus negatively affect their growth and productivity. Developing C 3 crop varieties with improved abiotic stress tolerances emerges as the most sustainable solution towards ensuring global food security under the predicted climate change scenario. Crassulacean Acid Metabolism (CAM) plants are considered well‐adapted to drought, heat, increased light intensities, higher UV irradiation, and are far more water‐use efficient compared to C 3 photosynthesis plants. The use of abiotic stress‐responsive transcription factors (TFs) from CAM plants is one feasible approach to improve crop production under adverse abiotic stress conditions. We have identified a NF‐YB TF from the heat‐tolerant obligate CAM plant Kalanchoe fedtschenkoi as a possible regulator of abiotic stresses. This NF‐Y is a ubiquitous transcription factor that is expressed as one of three possible isoforms NF‐YA, NF‐YB, or NF‐YC. Their isoforms interact to form a heterotrimeric complex with each subunit playing key roles in the abiotic stress responses including drought, heat, freezing, and salinity. We are functionally characterizing this KfNF‐YB via overexpression in Arabidopsis thaliana to determine its role in abiotic stress responses. Preliminary results following in vitro salinity stress assay of T 2 transgenic lines after 12 days in MS media with 200 mM NaCl indicate increased root growth, whereas the wild type had retarded root growth. In addition, transgenic lines had higher biomass dry weight compared to wild type after 12 days. T 2 lines also have increased rosette size in two‐week old transgenic A. thaliana compared to wild type. We will discuss the implications of the preliminary results as a potential strategy to enhance multiple abiotic stress tolerance responses in C 3 plants. Support or Funding Information This work is funded by South Dakota Board of Regents Grant #A18‐0015‐001 to BWM Wone and supported in part by U. S. Department of Energy, Office of Science, Genomic Science Program under award #DE‐SC0008834 to JC Cushman.