Oxathiapiprolin, a Novel Chemical Inducer Activates the Plant Disease Resistance

Qin Peng,Wenhui Li,Zhenzhen Zhao,Yinping Liang,Zhiwen Wang,Ye Xia,Xili Liu,Pengfei Liu

doi:10.3390/ijms21041223

Abstract

Oxathiapiprolin was developed as a specific plant pathogenic oomycete inhibitor, previously shown to have highly curative and protective activities against the pepper Phytophthora blight disease under field and greenhouse tests. Therefore, it was hypothesized that oxathiapiprolin might potentially activate the plant disease resistance against pathogen infections. This study investigated the potential and related mechanism of oxathiapiprolin to activate the plant disease resistance using the bacterium Pseudomonas syringae pv tomato (Pst) and plant Arabidopsis interaction as the targeted system. Our results showed that oxathiapiprolin could activate the plant disease resistance against Pst DC3000, a non-target pathogen of oxathiapiprolin, in Arabidopsis, tobacco, and tomato plants. Our results also showed the enhanced callose deposition and H2O2 accumulation in the oxathiapiprolin-treated Arabidopsis under the induction of flg22 as the pathogen-associated molecular pattern (PAMP) treatment. Furthermore, increased levels of free salicylic acid (SA) and jasmonic acid (JA) were detected in the oxathiapiprolin-treated Arabidopsis plants compared to the mock-treated ones under the challenge of Pst DC3000. Besides, the gene expression results confirmed that at 24 h after the infiltration with Pst DC3000, the oxathiapiprolin-treated Arabidopsis plants had upregulated expression levels of the respiratory burst oxidase homolog D (RBOHD), JA-responsive gene (PDF1.2), and SA-responsive genes (PR1, PR2, and PR5) compared to the control. Taken together, oxathiapiprolin is identified as a novel chemical inducer which activates the plant disease resistance against Pst DC3000 by enhancing the callose deposition, H2O2 accumulation, and hormone SA and JA production.

Highlights

Plants encounter numerous biotic and abiotic factors during their growth and development
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Summary

Introduction

Plants encounter numerous biotic and abiotic factors during their growth and development. The OX-treated Arabidopsis plants had significantly higher expression level of RBOHD than that of the mock-treated ones at 24-h post infiltration (hpi) with the Pst DC3000 (Figure 3C), which was consistent with the increased H2O2 accumulation in response to the flg treatment. Consistent with the hormone results, the OX-treated Arabidopsis plants had significantly higher expression levels of these three PR genes than the mock-treated ones at 24 hpi with the Pst DC3000 treatment (Figure 6A–C). The result showed that the expression level of PDF 1.2 was significantly higher in the OX-treated Arabidopsis plants than the mock-treated ones at 24 hpi with the Pst DC3000 treatment (Figure 6D), which was consistent with the JA accumulation. AwCaTsINuswedasasusthede ianstethrneailnrteefrenraelnrceefegreennec.eSgigenneif.icSaignnt idfiicffaenrtendciffeserbeentcweesebnettwheeeOnXt-htreeOatXed-trpelaatnetds palnadnttsheanmdotchke-tmreaotcekd-tprelaantetds wpelarnetisnwdiecraeteidndbiycathteedonbye-wthaeyoAneN-wOVayAAstNatOisVtiAcaslttaetsitstbiycaSlPteSsStvbeyr.S2P1S(Sp v

33.. Discussion

Plant Growth Conditions

The H2O2 Detection and Callose Deposition

Plant Hormone Extraction and Quantification

Findings

RNA Extraction and Gene Expression Quantification