Crude peptides extracted from dry mycelium of Penicillium chrysogenum serve as a micro-associated molecular pattern to induce systemic resistance against tobacco mosaic virus in tobacco

https://doi.org/10.1016/j.pmpp.2021.101677Get rights and content

Highlights

  • Penicillium chrysogenum activates defense responses to tobacco mosaic virus (TMV).

  • It induced systemic resistance via both SA and JA/ET signaling pathways.

  • It also accelerated TMV-N gene-triggered-HR without primed callose deposition.

Abstract

Control of viral diseases using systemic resistance-inducing microbes and microbial metabolites/molecules is an established alternative strategy for inhibiting plant viruses. However, the mechanisms whereby virus infection is inhibited and restricted in plants expressing systemic resistance remains poorly understood. We have previously reported that an aqueous extract of the dry mycelium of Penicillium chrysogenum (DMP) can be used to protect tobacco plants against Tobacco mosaic virus (TMV). In this study, we investigated the effect of crude peptides derived from DMP (PDMP) in protecting Nicotiana glutinosa against TMV. The number and diameter of TMV lesions in plants pre-treated with PDMP were fewer and smaller, respectively, than those in control plants. The elevated expressions of PAL, PTI5, PR-1a, NPR1, PR-1b, and PDF1.2 detected in the induced and systemic leaves following PDMP treatment indicated that the PDMP induced basal and systemic resistance in N. glutinosa. Callose deposition and TMV-N gene-triggered hypersensitive response (HR) at the site of the TMV infection were identified as key factors restricting the movement of viruses. The levels of N gene transcripts, as well as those of the TMV-N gene-triggered HR-related genes HSR203J, AOXa, SIPK, and ZFT1 increased more rapidly after being challenged with TMV in N. glutinosa plants pre-treated with PDMP compared with the control plants. However, we detected no significant difference between PDMP-treated and control plants with respect to TMV-induced callose deposition, indicating that PDMP enhances the resistance of N. glutinosa against TMV by accelerating TMV-N gene-triggered-HR rather than by priming callose deposition.

Introduction

Plants inhabit complex environments and are often attacked by a diverse range of pathogens and predators. Plants have adapted to different environments by evolving sophisticated defense mechanisms against pathogens. Consequently, when attacked by pathogens, plants may initiate defense-related reactions, resulting in systemic resistance against subsequent pathogen challenge [1]. Systemic resistance is characterized as an enduring broad-spectrum protection against diverse invaders, including plant viruses.

Numerous studies have shown that beneficial microorganisms, attenuated strains of pathogenic microorganisms, and endophytes in plant roots, as well as the fermentation broths and fermentation broth extracts of these agents are able to induce plant resistance against viral diseases. Harpaz et al. [2], for example, found that Thielaviopsis basicola and an extract of the fermentation broth of this bacterium can inhibit the systemic infection of Tobacco mosaic virus (TMV). Over the past two decades, numerous plant growth-promoting rhizosphere fungi and bacteria have been isolated from soils [3], some of which, including species of Pseudomonas, Serratia, Bacillus, Trichoderma, and Paenibacillus, have proved to be effective in inducing of plant resistance to viral diseases, These plant growth-promoting microorganisms have accordingly attracted widespread research attention with respect to their impressive potential for inducing plant resistance in both greenhouse and field trials [4]. There is increasing evidence that certain species of Bacillus and Paenibacillus can induce resistance in tobacco, tomato, soybean, cucumber, Arabidopsis and other plants against cucumber mosaic virus (CMV) [[5], [6], [7], [8]], tobacco necrosis virus (TNV) [9], bean common mosaic virus (BCMV) [10], cucumber green mottle mosaic virus (CGMMV) [11], and other viral diseases [12,13]. Furthermore, the photosynthetic bacterium Rhodopseudomonas palustris GJ-22 has been found to induce plant systemic resistance and enable tobacco plants to withstand infection by TMV [14], whereas growth-promoting fungi have been found effective in inducing CMV and TMV resistance in tomato, tobacco, and other crops [[15], [16], [17], [18]]. In addition, the fermentation broths of certain bacteria can serve as elicitors to induce plant resistance against viral diseases. For example, non-phytotoxic strains of Streptomyces spp. can be effective in the systemic control of CMV infection in Chenopodium amaranticolor [19]. whereas Pseudomonas aeruginosa (formulated in the forms of dry powder, liquid, or gel) can induce systemic resistance in soybean [20], and the plant growth-promoting fungus Penicillium chrysogenum and its dry mycelia have been shown to elicit resistance against fungal diseases in pearl millet [21], melon [22], cotton [[23], [24], [25], [26], [27]], and other crops [28]. In this regard, we have previously demonstrated that a water extract of the dry mycelium of Penicillium chrysogenum (DMP) activates defense responses in tobacco BY-2 cell suspensions and protects tobacco plants from TMV [29]; however, the mechanisms whereby this elicitor triggers resistance to TMV have yet to be determined.

The incompatible interaction between plants and viruses depends on R gene-mediated recognition of avirulence (Avr) factors. The N gene is a typical R gene identified in tobacco, and it has been established that the interaction between N gene-harboring tobacco (NN tobacco) and tobacco mosaic virus (TMV) results in TMV resistance in both the infected and non-infected upper leaves of affected plants [30]. N gene-mediated TMV recognition initiates a hypersensitive response (HR) and development of lesions at the site of infection [31], with the number and size of TMV lesions being negatively associated with resistance in NN tobacco [32]. We believe that HR-related programed cell death limits the virus to the initial site of infection, thereby inhibiting its reproduction and spread. In the process of N gene-mediated TMV recognition, callose also accumulates around plasmodesmata at the site of infection, thereby further restricting the spread of TMV [33,34]. Consequently, during the interaction between TMV and tobacco plants carrying the N gene, TMV-N gene-triggered HR and callose deposition at the site of infection are considered key factors in limiting the spread of the virions.

We previously established that PDMP treatment can restrict the spread of TMV by priming callose deposition in Nicotiana benthamiana (a tobacco lacking the N gene) [35]. However, the effect of PDMP on the interaction between N gene-harboring tobacco and TMV has yet to be determined. In the present study, we examined the PDMP-induced resistance against TMV in N gene-harboring Nicotiana glutinosa, and characterized the TMV-N gene-triggered HR and accumulation of callose during the incompatible interaction between TMV and N. glutinosa to gain insights into the mechanisms whereby PDMP enhances host resistance against TMV.

Section snippets

Preparation of PDMP

Powdered dry mycelium of P. chrysogenum, provided by Shandong Lukang Pharmaceutical Company Ltd. (Jinan, Shandong Province, China), was dissolved in deionized water (100 mg/mL), vacuum-filtered to remove water-insoluble compounds, and mixed slowly with ammonium sulfate, added to saturation (approx. 95% ammonium sulfate). This solution was left overnight at 4 °C, after which the resulting precipitate was collected by centrifugation at 3000 rpm and 4 °C for 15 min and re-dissolved in deionized

PDMP enhances resistance against TMV in N. glutinosa

N. glutinosa leaves were treated with 0.1, 0.5, 1.0, or 2.0 mg/mL PDMP and 5 days later, TMV was rubbed over the surface of the PDMP-treated lower leaves (induced leaves) and untreated upper leaves (systemic leaves). The results showed that the number and area of TMV lesions in all PDMP-treated groups were respectively fewer and smaller than those in the control (Fig. 1), with even the lowest PDMP concentration (0.1 mg/mL) being found to be effective in inducing TMV resistance in N. glutinosa.

Discussion

Induced resistance is a defense-related mechanism activated in plants by pathogen infection, in response to which, systemic signals are initiated at the site of infection and in turn trigger defense responses in distant parts, eventually inducing widespread systemic resistance. Our examination of the responses to treatment with different concentrations of PDMP indicated that 1 mg/mL PDMP was sufficient to induce effective plant resistance against TMV. Compared with the control, PDMP at this

Conclusion

The findings of this study provide evidence of the efficacy of PDMP in enhancing resistance against TMV in N. glutinosa. PDMP was found to induce systemic resistance via both SA and JA/ET signaling pathways and by accelerating a TMV-N gene-triggered hypersensitive response in the absence of primed callose deposition.

Funding source

This study was supported by the Yunnan Fundamental Research Projects (no. 2018FA022), the National Natural Science Foundation of China (no. 31660038), and the Yunnan Tobacco Company program (grant 2018530000241013).

CRediT authorship contribution statement

Yu Zhong: Methodology, Software, Validation, Writing – original draft. Yu Li: Methodology, Software, Validation, Writing – original draft. Kun Huang: Methodology, Software. Zhuang-zhuang Chen: Methodology, Software. Jian Fu: Methodology, Software. Chun-ming Liu: Methodology. Sui-yun Chen: Conceptualization, Supervision, Writing – review & editing. Jian-guang Wang: Conceptualization, Funding acquisition, Project administration, Supervision, Writing – review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (51)

  • C.M. Ryu et al.

    Plant growth-promoting rhizobacteria systemically protect Arabidopsis thaliana against Cucumber mosaic virus by a salicylic acid and NPR1-independent and jasmonic acid-dependent signaling pathway

    Plant J.

    (2004)
  • C.M. Ryu et al.

    A two-strain mixture of rhizobacteria elicits induction of systemic resistance against Pseudomonas syringae and Cucumber mosaic virus coupled to promotion of plant growth on Arabidopsis thaliana

    J. Microbiol. Biotechnol.

    (2007)
  • S. Kumar et al.

    Paenibacillus lentimorbus inoculation enhances tobacco growth and extenuates the virulence of cucumber mosaic virus

    PloS One

    (2016)
  • M. Maurhofer et al.

    Induction of systemic resistance of tobacco to tobacco necrosis virus by the root-colonizing Pseudomonas fluorescens strain CHA0: influence of the gacA gene and of pyoverdine production

    Phytopathology

    (1994)
  • A.C. Udaya Shankar et al.

    Rhizobacteria-mediated resistance against the blackeye cowpea mosaic strain of bean common mosaic virus in cowpea (Vigna unguiculata)

    Pest Manag. Sci.

    (2009)
  • H. Li et al.

    Stenotrophomonas maltophilia HW2 enhanced cucumber resistance against cucumber green mottle mosaic virus

    J. Plant Biol.

    (2016)
  • G. Berg

    Beyond borders: investigating microbiome interactivity and diversity for advanced biocontrol technologies

    Microb. Biotechnol.

    (2015)
  • S. Rajamanickam et al.

    Flagellin of Bacillus amyloliquefaciens works as a resistance inducer against groundnut bud necrosis virus in chilli (Capsicum annuum L.)

    Arch. Virol.

    (2020)
  • P. Su et al.

    Photosynthetic bacterium Rhodopseudomonas palustris GJ-22 induces systemic resistance against viruses

    Microbial. Biotechnol.

    (2017)
  • Y. Luo et al.

    Antimicrobial peptaibols induce defense responses and systemic resistance in tobacco against tobacco mosaic virus

    FEMS Microbiol. Lett.

    (2010)
  • A. Vitti et al.

    Trichoderma harzianum T-22 induces systemic resistance in tomato infected by cucumber mosaic virus

    Front. Plant Sci.

    (2016)
  • M.M. Elsharkawy et al.

    Systemic resistance induced by Phoma sp. GS8-3 and nanosilica against Cucumber mosaic virus

    Environ. Sci. Pollut. Res. Int.

    (2020)
  • L. Miozzi et al.

    Arbuscular mycorrhizal symbiosis primes tolerance to cucumber mosaic virus in tomato

    Viruses

    (2020)
  • K.A. El-Dougdou et al.

    Biological control of cucumber mosaic virus by certain local Streptomyces isolates: inhibitory effects of selected five Egyptian isolates

    Int. J. Virol.

    (2012)
  • K. Khalimi et al.

    Induction of plant resistance against Soybean stunt virus using some formulations of Pseudomonas aeruginosa

    ISSAAS

    (2011)
  • Cited by (1)

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    Y. Zhong and Y. Li contributed equally to this work.

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