A secreted catalase contributes to Puccinia striiformis resistance to host-derived oxidative stress

Pu Yuan,Conghui Jia,Wenhao Qian,Zhensheng Kang,Jie Liu,Lihua Jiang,Xiaoxuan Ma

doi:10.1007/s44154-021-00021-2

Pu Yuan, Conghui Jia + Show 5 more

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https://doi.org/10.1007/s44154-021-00021-2

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Journal: Stress Biology	Publication Date: Dec 1, 2021
Citations: 4	License type: open-access

Affiliation: North West Agriculture and Forestry University

Abstract

Plants can produce reactive oxygen species (ROS) to counteract pathogen invasion, and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity. Catalases (CATs) have been found to play pivotal roles in detoxifying H2O2 formed by superoxide anion catalyzed by superoxide dismutases (SODs). However, few studies have addressed H2O2 removing during rust fungi infection of wheat. In this study, we cloned a CAT gene PsCAT1 from Puccinia striiformis f. sp. tritici (Pst), which encodes a monofunctional heme-containing catalase. PsCAT1 exhibited a high degree of tolerance to pH and temperature, and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional. Overexpression of PsCAT1 enhanced S. cerevisiae resistance to H2O2. Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death. Knockdown of PsCAT1 using a host-induced gene silencing (HIGS) system led to the reduced virulence of Pst, which was correlated to H2O2 accumulation in HIGS plants. These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H2O2.

Highlights

The burst of reactive oxygen species (ROS) is the early immune responses of the host to pathogens
The results showed that the PsCAT1 transcript in barley stripe mosaic virus (BSMV)-PsCAT1as1-inoculated leaves was reduced by 68%, 57%, 28% and 63% at 24, 48, 72 and 120 hpi respectively; in leaves inoculated with BSMV-PsCAT1as2, the PsCAT1 expression level was decreased by 68%, 77%, 81% and 63% respectively, compared with BSMV-γ-infected wheat leaves (Fig. 6d)
The results showed that H2O2 accumulation was significantly increased, especially in the anterior part of the haustorial mother cells (HMC), in the wheat seedings inoculated with BSMVPsCAT1as1 and BSMV-PsCAT1as2 compared with the control plants at 24 and 48 hpi (Fig. 7d, e, i, j and n)

Summary

Introduction

The burst of reactive oxygen species (ROS) is the early immune responses of the host to pathogens. According to its physical and biochemical characteristics, CATs are divided into four types: typical catalase (monofunctional), catalase-peroxidase (bifunctional), non-heme catalase (pseudo-catalases) and minor catalase (Chelikani et al, 2004; Sooch et al, 2014). Bifunctional catalase is a (2021) 1:22 heme enzyme and has the catalytic activity of peroxidase (Zámocký and Koller, 1999; Kapetanaki et al, 2007). Pseudo-catalase is a heme-free catalase, which replaces the active center with a divalent manganese ion (Sooch et al, 2014). Minor catalase containing heme exhibits a very low level of catalytic activity, such as chloroperoxidase, bromoperoxidase, and catalase-phenol oxidase (Nicholls et al, 2001; Vetrano et al, 2005)

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