Differential expression of in response to nitric oxide suggests a putative role in biotic and abiotic stress responses.

Plant defense against pathogens and abiotic stresses is regulated differentially by communicating signal transduction pathways in which nitric oxide (NO) plays a key role. Here, we show the biological role of wall-associated kinase (AtWAK) Like10 () that exhibits greater than a 100-fold change in transcript accumulation in response to the NO donor S-nitroso-L-cysteine (CysNO), identified from high throughput RNA-seq based transcriptome analysis. Loss of function showed a similar phenotype to wild type (WT) with, however, less branching. The growth of on media supplemented with oxidative or nitrosative stress resulted in differential results with improved growth following treatment with CysNO but reduced growth in response to -nitrosoglutatione (GSNO) and methyl-viologen. Further, plants exhibited increased susceptibility to virulent pv tomato () DC3000 with a significant increase in pathogen growth and decrease in transcript accumulation compared to WT overtime. Similar results were found in response to DC3000 avrB, resulting in increased cell death as shown by increased electrolyte leakage in . Furthermore, also showed increased reactive oxygen species accumulation following DC3000 avrB inoculation. Promoter analysis of showed transcription factor (TF) binding sites for biotic and abiotic stress-related TFs. Further investigation into the role of in abiotic stresses showed that following two weeks water-withholding drought condition most of the plants got wilted; however, the majority (60%) of these plants recovered following re-watering. In contrast, in response to salinity stress, showed reduced germination under 150 mM salt stress compared to WT, suggesting that NO-induced differentially regulates different abiotic stresses. Taken together, this study further elucidates the importance of NO-induced changes in gene expression and their role in plant biotic and abiotic stress tolerance.