Differential expression of AtWAKL10 in response to nitric oxide suggests a putative role in biotic and abiotic stress responses

Phearom Bot; Bong-Gyu Mun; Qari Muhammad Imran; Adil Hussain; Sang-Uk Lee; Gary Loake; Byung-Wook Yun

doi:10.7717/peerj.7383

Differential expression of AtWAKL10 in response to nitric oxide suggests a putative role in biotic and abiotic stress responses

PeerJ. 2019 Aug 16:7:e7383. doi: 10.7717/peerj.7383. eCollection 2019.

Authors

Phearom Bot^#¹, Bong-Gyu Mun^#¹, Qari Muhammad Imran¹, Adil Hussain², Sang-Uk Lee¹, Gary Loake³, Byung-Wook Yun¹

Affiliations

¹ Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea.
² Department of Agriculture, Abdul Wali Khan University Mardan, Mardan, Pakistan.
³ Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK.

^# Contributed equally.

Abstract

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 Arabidopsis thaliana wall-associated kinase (AtWAK) Like10 (AtWAKL10) 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 AtWAKL10 function showed a similar phenotype to wild type (WT) with, however, less branching. The growth of atwakl10 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 S-nitrosoglutatione (GSNO) and methyl-viologen. Further, atwakl10 plants exhibited increased susceptibility to virulent Pseudomonas syringae pv tomato (Pst) DC3000 with a significant increase in pathogen growth and decrease in PR1 transcript accumulation compared to WT overtime. Similar results were found in response to Pst DC3000 avrB, resulting in increased cell death as shown by increased electrolyte leakage in atwakl10. Furthermore, atwakl10 also showed increased reactive oxygen species accumulation following Pst DC3000 avrB inoculation. Promoter analysis of AtWAKL10 showed transcription factor (TF) binding sites for biotic and abiotic stress-related TFs. Further investigation into the role of AtWAKL10 in abiotic stresses showed that following two weeks water-withholding drought condition most of the atwakl10 plants got wilted; however, the majority (60%) of these plants recovered following re-watering. In contrast, in response to salinity stress, atwakl10 showed reduced germination under 150 mM salt stress compared to WT, suggesting that NO-induced AtWAKL10 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.

Keywords: AtWAKL10; Basal defense; Drought; Effector-triggered immunity; Promoter analysis; Salt stress.

Grants and funding

This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education Grant Number NRF-2017R1A2B1008820. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.