Genome-Wide Analysis of the WRKY Gene Family in Malus domestica and the Role of MdWRKY70L in Response to Drought and Salt Stresses

Genes (Basel). 2022 Jun 15;13(6):1068. doi: 10.3390/genes13061068.

Abstract

The WRKY transcription factors are unique regulatory proteins in plants, which are important in the stress responses of plants. In this study, 113 WRKY genes were identified from the apple genome GDDH13 and a comprehensive analysis was performed, including chromosome mapping, and phylogenetic, motif and collinearity analysis. MdWRKYs are expressed in different tissues, such as seeds, flowers, stems and leaves. We analyzed seven WRKY proteins in different groups and found that all of them were localized in the nucleus. Among the 113 MdWRKYs, MdWRKY70L was induced by both drought and salt stresses. Overexpression of it in transgenic tobacco plants conferred enhanced stress tolerance to drought and salt. The malondialdehyde content and relative electrolyte leakage values were lower, while the chlorophyll content was higher in transgenic plants than in the wild-type under stressed conditions. In conclusion, this study identified the WRKY members in the apple genome GDDH13, and revealed the function of MdWRKY70L in the response to drought and salt stresses.

Keywords: MdWRKY70L; WRKY family; apple; drought stress; salt stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Droughts*
  • Gene Expression Regulation, Plant
  • Malus* / genetics
  • Phylogeny
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Salt Stress / genetics
  • Stress, Physiological / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Plant Proteins
  • Transcription Factors

Grants and funding

This work was supported by the National Key Research and Development Program of China (2018YFD1000300), the earmarked fund for the China Agricultural Research System (CARS-27), and the Key S&T Special Projects of Shannxi Province (2020zdzx03-01-02), and the Natural Science Basic Research Program of Shaanxi (2022JQ-178).