The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum

Abstract

Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought.

Overexpression of MoSM1, encoding for an immunity-inducing protein from Magnaporthe oryzae, in rice confers broad-spectrum resistance against fungal and bacterial diseases

“…tomato DC3000)42. These data indicate that MoSM1, like other CPs from both beneficial and pathogenic fungi4447, confers a broad-spectrum resistance against pathogens with different life styles in host and nonhost plants, providing a great potential for application of MoSM1 in genetic improvement of disease resistance in other crop plants. The MoSM1-OE plants did not show a decreased resistance against sheath blight disease, although they did not gain an increased resistance (Fig.…”

“…Indeed, a number of CPs from different filamentous fungi, e.g. SM1, SM2 and Epl1 from the biocontrol agents T. virens and T. atroviride 37404547 as well as BcSpl1 from B. cinerea and a CP from C. platani 2944, were shown to induce both local and systemic disease resistance in host and nonhost plants against different life style pathogens. In the present study, we found that overexpression of MoSM1 in transgenic rice plants confers an improved resistance against two strains representing difference races of M. oryzae and Xoo , as revealed by reduced disease severity and suppressed in planta pathogen growth (Figs 3 and 4).…”

“…Meanwhile, it has also been shown that CPs from both pathogenic and beneficial biocontrol fungi can induce locally and systemically some structural, physiological and molecular defense responses, including initiation of hypersensitive response (HR), accumulation of phenolic compounds and phytoalexins, production of reactive oxygen species (ROS), and upregulation of defense-related genes in host and nonhost plants33343536373839404142434445. SM1 and SM2 from Trichoderma virens , BcSpl1 from B. cinerea , and MoSM1 (also known as MoMSP1) from M. oryzae could induce systemic disease resistance in rice, cotton, maize, tobacco, tomato and Arabidopsis against different pathogens3237384042454647 and the activation of systemic resistance by CP from C. platani and BcSpl1 from B. cinerea was found to be regulated through stomatal perception, overexpression of salicylic acid (SA)- and ethylene-signaling genes and camalexin biosynthesis4446. Further study revealed that the elicitor activity of the B. cinerea BcSpl1 resides in a two-peptide motif on the protein surface29.…”

Different mechanisms of Trichoderma virens‐mediated resistance in tomato against Fusarium wilt involve the jasmonic and salicylic acid pathways

“…A recent study by Salas‐Marina et al . () reported that Sm1 and eliciting plant response‐like protein 1 (Epl1), secreted by T. virens and T. atroviride , induced resistance against Alternaria solani , B. cinerea and P. syringae pv. tomato in tomato.…”

Elicitation of resistance and associated defense responses in Trichoderma hamatum induced protection against pearl millet downy mildew pathogen

“…Transcriptional analysis of downy mildew resistance induced by Trichoderma harzianum T39 in susceptible grapevines showed complex transcriptional reprogramming resulting in enhanced expression of PAL, PPO, PR-1 and PR-5 genes31. The transcripts of glucanase and POX enzymes and PR-5 were significantly enhanced during of Trichoderma atroviride and Trichoderma virens secretory proteins mediated resistance against Alternaria solani, Botrytis cinerea and Pseudomonas syringae 32. In tomato, Trichoderma hamatum 382 induced resistance against Xanthomonas vesicatoria in tomato and Botrytis cinerea in Arabidopsis thaliana correlated with enhanced expression of PR-5 genes67.…”