The wheat C2H2 zinc finger protein TaZFP13D modulates the expression of chloroplast-related genes, improves growth and drought stress tolerance.
Background  Maintaining global food security in the context of climate changes is an important challenge in the next century. Improving abiotic stress tolerance of major crops, like wheat, can contribute to this goal. Therefore, new genes improving tolerance to abiotic stresses, like drought, are needed to support breeding programs aimed at producing more adapted cultivars. Recently, we screened five wheat Zinc Finger Proteins (TaZFPs) and identified TaZFP13D as a new gene improving water-stress tolerance. However, a more detailed characterization of this gene is required to better evaluate its potential in drought tolerance and to decipher the underlying molecular basis.    Results  We used the Barley Stripe Mosaic Virus to up- or down-regulate TaZFP13D expression in wheat. Overexpression of TaZFP13D under well-watered conditions enhances growth as indicated by improved biomass. Exposing plants to a severe drought stress revealed that TaZFP13D strongly increases survival rate and stress recovery. In addition, TaZFP13D reduces drought-induced oxidative damages, at least in part by improving key antioxidant enzymes activity. Conversely, down-regulation of TaZFP13D decreases drought tolerance and protection against drought-induced oxidative damages. RNA-seq-based transcriptome analysis showed that many genes regulated by TaZFP13D were previously shown to improve drought tolerance, while many others are related to the photosynthetic electron transfer chain and are proposed to improve photosynthesis efficiency and chloroplast protection against ROS damages.    Conclusion  This study highlights the important role of TaZFP13D in wheat drought tolerance, contributes to unravel the complex regulation governed by TaZFPs, and provides a useful marker to select more drought tolerant wheat cultivars. Overall design: Examination of wheat second leaf transcript profiles modification in 4 wheat plant types under well watered condition and drought condition.