Potassium ion channel gene family provides new insights into powdery mildew responses in Triticum aestivum

The chromosomal localization, gene structure, transmembrane proteins, and transcriptome of the wheat Shaker family genes were analysed. The expression patterns of wheat Shaker genes under different stresses were investigated using reverse transcription quantitative PCR (RT-qPCR). The effect of potassium ion treatment on wheat disease severity caused by powdery mildew was evaluated. To further investigate whether wheat Shaker genes also have inhibitory effects on other pathogens, Nicotiana benthamiana transiently overexpressing Shaker genes was inoculated with Phytophthora infestans and the effects on P. infestans infection judged by leaf lesion diameter. A total of 25 Shaker genes were identified in wheat (TaShaker genes) and were classified into four groups based on phylogenetic analysis. Chromosome mapping results indicated that the 25 TaShaker genes were distributed on 14 chromosomes in wheat (2B, 4A, 4B, 4D, 5A, 5B, and 5D). Gene structure analysis revealed the untranslated region structures were missing in some TaShaker genes, with the number of introns ranging from 7 to 11. Protein transmembrane prediction analysis indicated that there were multiple TaShaker transmembrane proteins. The results of the RT-qPCR analysis indicated that TaShaker genes were not only involved in regulating drought stress, but could also resist infection by Fusarium graminearum and powdery mildew. This study also found that spraying potassium ion solutions at the seedling stage could reduce the severity of powdery mildew infection in wheat. Moreover, transient overexpression of TaShaker5.1-3A in N. benthamiana leaves could inhibit P. infestans infection.