Functional Analysis of Wheat NAC Transcription Factor, TaNAC069, in Regulating Resistance of Wheat to Leaf Rust Fungus.

Yanjun Zhang,Zhongchi Cui,Daqun Liu,Huaimin Geng,Haiyan Wang

doi:10.3389/fpls.2021.604797

Abstract

NAC transcription factors are one of the largest transcription factor families having functions in a variety of stress responses. Few NACs have been reported for interactions between wheat and the wheat rust fungus Puccinia triticina (Pt). In this study, based on analysis of RNA-seq data from wheat line TcLr19 inoculated by Pt, the NAC transcription factor TaNAC069 was cloned from wheat, and its transcriptional activity and homologous dimer formation were verified. Quantitative real-time PCR analysis showed that the expression of TaNAC069 was induced by Pt and associated signaling molecules. To further characterize the function of the TaNAC069 gene in wheat resistance to Pt, virus-induced gene silencing (VIGS) was utilized, and it revealed that Pt resistance in TaNAC069-silenced plants was significantly reduced. Potential interaction targets of TaNAC069 from wheat and Pt were screened and identified by yeast two-hybrid technology. Eukaryotic elongation factor eEF1A, CBSX3 protein, and cold acclimation protein WCOR410c were screened by yeast one-hybrid technology. The results indicate that the TaNAC069 gene plays a positive regulatory role in wheat resistance to Pt, laying a good foundation to analyze the molecular mechanisms of TaNAC069 and its functional role in wheat resistance to Pt.

Highlights

At the transcriptional level, controlling gene expression is key to regulate many plant cell responses, including normal signal transduction and cell morphological changes in response to stress (Hu et al, 2010)
A 1259-bp fragment was identified and cloned based on RNAseq data via reverse transcription polymerase chain reaction (RT-PCR) (Supplementary Figure 1); sequence analysis showed that it belongs to the NAC transcription factor family, as expected
Further analysis confirmed its homology with typical NAC transcription factors, such as Arabidopsis thaliana ATAF1 (X74755) (36.6%), A. thaliana TIP (AF281062) (46.91%), Oryza sativa OsNAC3 (AB028182) (54.50%), Petunia hybrida NAM (X92204) (54.49%), NAC-like NAP (AJ222713) (56%), and Lycopersicon esculentum SENU5 (Z75524) (54.22%) (Figure 1B)

Summary

Introduction

At the transcriptional level, controlling gene expression is key to regulate many plant cell responses, including normal signal transduction and cell morphological changes in response to stress (Hu et al, 2010). Many studies have shown that transcription factors regulate the expression of stressrelated genes to activate or repress the expression of target genes involved in stress responses (Erpen et al, 2018). NAC transcription factors are one of the largest families of plant-specific transcription factors that respond to biotic and abiotic stresses by participating in plant stress signal transduction pathways and regulating the expression of downstream target genes (Zhang et al, 2018). The C-terminus of NAC is rich in serine, threonine, proline, and some acidic amino acids and can activate or repress the expression of downstream target genes (Olsen et al, 2005). The C-terminus may have transcriptional activity, containing different motifs having specific functions

Methods

Results

Conclusion