Overexpression of TaSNAC4-3D in Common Wheat (Triticum aestivum L.) Negatively Regulates Drought Tolerance

Abstract

The development and production of bread wheat (Triticum aestivum L.) are widely affected by drought stress worldwide. Many NAC transcription factors (TFs) of stress-associated group (SNAC) are functionally proven to regulate drought tolerance. In this study, we identified 41 TaSNACs that were classified into 14 groups, and the expression of TaSNAC4-3D was induced in the leaf tissue via osmotic or abscisic acid (ABA) treatment. TaSNAC4-3D was localized to the nucleus through the transient expression assay, and the C-terminal region exhibited transcriptional activity via transactivation assays. TaSNAC4-3D was overexpressed in common wheat. The wheat plants with TaSNAC4-3D overexpression was more sensitive to drought stress compared with wild-type (WT) plants. The water loss rate showed no difference between transgenic lines and WT plants. However, drought stress increased H2O2 and O2– accumulation and promoted programmed cell death (PCD) in the leaf tissue of TaSNAC4-3D overexpression lines compared with WT plants. RNA-seq analysis was performed under well-watered and drought conditions, and four strong potential target genes, encoding senescence regulators, were identified by analyzing their promoters containing the NAC recognition sequence (NACRS). Based on these results, our findings revealed that TaSNAC4-3D negatively regulates drought tolerance by inducing oxidative damage in bread wheat.

Transcriptome-wide identification of NAC (no apical meristem/Arabidopsis transcription activation factor/cup-shaped cotyledon) transcription factors potentially involved in salt stress response in garlic

“…AfNAC1 from Amorpha fruticosa may have a part in photosystem regulation and indirectly confer plant resistance to drought stress ( Li et al, 2022 ). By contrast, TaSNAC4-3D negatively regulated drought tolerance by bringing about increased oxidative damage and programmed cell death in wheat ( Ma et al, 2022 ). Compared with control lines, transgenic tomato plants overexpressing Prunus persica PpNAC56 could accumulate more osmoregulatory substances when exposed to high temperature and thus were more tolerant ( Meng et al, 2022 ).…”

Unraveling the regulatory role of MYC2 on ASMT gene expression in wheat: Implications for melatonin biosynthesis and drought tolerance

“…Then, the leaf tissue of 30 days old plants under well‐watered conditions and the 50 and 40% field capacity (FC) of soil with three biological replicates were sampled. After that, RNA from leaves was extracted, and paired‐end sequenced on the Illumina HiSeq‐PE150 platform (Ma et al, 2022a).…”

“…Publicly available RNA-Seq data from a recently conducted study by Ma et al (2022a) were used in the analysis. For this purpose, we downloaded only the FASTQ files of control and drought stress in soil conditions from the Sequence Read Archive (SRA) of NCBI (https:// www.ncbi.nlm.nih.gov/sra) with the BioProject ID of PRJNA838079.…”

Cis-Regulation by NACs: A Promising Frontier in Wheat Crop Improvement

“…Stress-related NAC TFs are denoted as SNAC and there are at least 41 stress-related SNAC TFs that fall into 14 different groups by phylogenic analysis. TaSNAC4-3D encodes one of those drought stress-related NAC TFs that negatively regulates drought stress in wheat when induced by ABA, leading to oxidative damage to plant cells [ 110 ]. TaSNAC4-3A overexpression in Arabidopsis resulted in increased tolerance to drought by regulating stomatal opening [ 111 ].…”