Characterization of a novel zinc finger transcription factor (TaZnF) from wheat conferring heat stress tolerance in Arabidopsis.

C3HC4-type zinc finger proteins are known to play important roles in various plant processes including regulation of growth and development, signaling networks, responses to abiotic stresses etc. The current study identifies and explores the involvement of TaZnF in plant stress response, mainly heat stress. TaZnF belongs to C4HC3-type zinc finger transcription factor. Phylogenetic analysis of TaZnF revealed strong sequence similarity to Brachypodium distachyon, a model system for crop species. Gene expression studies have revealed its role under diverse stress conditions including heat and cold conditions. The transcript level of TaZnF was found to be highest in seed and starts at the post anthesis period 3-5DAA, a more sensitive stage resulting in a negative influence on the yield of crop species. TaZnF possesses transcriptional activity. Overexpression of TaZnF in Arabidopsis thaliana conferred improved tolerance to both basal and high-temperature stress as observed from various assays examining their growth and development. The transgenics were recovered and showed early flowering compared to wild-type. They had larger primary roots, more lateral branching, bigger, and more numerous leaves, resulting in heavier fresh weight. Enhanced growth and early recovery resulted in bigger plants with more yield. Additionally, the overexpression Arabidopsis transgenics also showed considerable tolerance to cold and oxidative stress. These observations suggest that TaZnF acts as a positive regulator of thermal stress and thus can be of great significance in understanding and improving temperature stress tolerance in plants.