Multiple roles of TaCPP family genes during growth and stress treatment

Abstract

The Cysteine-rich polycomb-like protein (CPP) family encodes animal and plant-specific transcription factors that are important for plant development and stress responses. Even though CPP family genes had been studied in many plants, nothing was known about them in common wheat (Triticum aestivum). The current research focused on a comprehensive discovery and characterization of wheat CPP (TaCPP) gene family members. Altogether 30 TaCPP genes were discovered and were divided into two groups and three subgroups based on the phylogenetic relationship. Gene structures and motif patterns of TaCPP genes were different in these three subgroups. Collinearity analysis revealed that segmental duplication was the most common mechanism of TaCPP gene family expansion. The expression levels of most TaCPP genes were high in reproductive tissues, such as ovaries and stigmas, implying that these genes may have a vital function in the reproduction of wheat. Further quantitative real-time polymerase chain reaction research demonstrated that all examined TaCPPs were significantly induced after drought, heat treatment, and Fusarium graminearum infection, showing that they were involved in the response to stress tolerance. The subcellular localization results of TaCPP14-5A and TaCPP15-5D show that both were located in the nucleus. In addition, transient expression TaCPP15-5D promoted resistance to Phytophthora infestans in Nicotiana benthamiana. Our findings lay the foundation for revealing the role of TaCPPs and will aid in the discovery of their regulatory networks in wheat growth and stress responses.