Antagonism of Trichoderma spp. against Macrophomina phaseolina: Evaluation of Coiling and Cell Wall Degrading Enzymatic Activities

Abstract

Materials and Methods Sources of Trichoderma sppSlants of six species of Trichoderma (T. harzianum NBAII Th 1; T. viride NBAII Tv 23; T. virens NBAII Tvs 12; T. koningi MTCC 796; T. pseudokoningi MTCC 2048; T. hamatum NBAII Tha-1.) were obtained either from IARI, New delhi or from MTCC, Chandigarh. One local isolate of T. harzianum was also collected from culture collection of Department of Plant Pathology, Junagadh Agricultural University, Junagadh. Isolation of phytopathogenic fungiMacrophomina phaseolina (Tassi) Goid was used as pathogen. The castor plants showing typical symptoms of root rot were collected AbstractIn vitro potentialities of seven species of Trichoderma were evaluated against phytopathogen Macrophomina phaseolina by dual culture techniques. The maximum growth inhibition of test pathogen was observed by antagonist T. koningi MTCC 796 (T4) (74.3%) followed by T. harzianum NABII Th 1 (T1) (61.4%) at 7 days after inoculation (DAI). Further, mycoparasitism of antagonists were observed upto 14 DAI. Pattern of growth inhibition of test fungus was continued with maximum 14.7% increases in T4 (85.2%) followed by 6.8% elevation in T1 (65.6%) antagonists during 7 to 14 DAI. Microscopic study showed that these two antagonists were capable of overgrowing and degrading M. phaseolina mycelia, coiling around the hyphae with apressoria and hook-like structures. At 14 DAI, T. koningi MTCC 796 completely destroyed the host and sporulated. The specific activities of cell wall degrading enzymes-chitinase, β-1, 3 glucanase, protease and cellulase were tested during different incubation period (24, 48, 72 and 96 h) when Trichoderma spp. grew in presence of pathogen cell wall in synthetic media. The antagonist T. koningi MTCC 796 induced higher chitinase and protease activity at 24 h incubation while β-1, 3 glucanase activities was elevated 1.18 fold during 72 to 96 h. Total phenol was produced significantly higher in culture supernatant of T. koningi MTCC 796 antagonist followed by T. hamatum NBAII Tha 1 and T. harzianum NBAII Th 1 at 48 h incubation. The growth inhibitions of pathogen during antagonism was positively correlated with coiling pattern of antagonists at 14 DAI, and induction of chitinase, β-1, 3 glucanase and total phenol content.

Macrophomina phaseolina: General Characteristics of Pathogenicity and Methods of Control

“…to overgrowth and degrade the pathogen mycelia (coiling around the hyphae with apressoria and hook-like structure). The induction of chitinase, β-1, 3 glucanase and increase in total phenol content was also observed, suggesting their role in growth inhibition of pathogen during antagonism (Gajera et al, 2012). Similarly, Brettanomyces naardensis, an antagonistic and growthpromoting yeast, is a potent biocontrol agent for M. phaseolina that colonizes fungal hyphae causing malformation and damage (Nafady et al, 2019).…”

Phytohormones (Auxin, Gibberellin) and ACC Deaminase In Vitro Synthesized by the Mycoparasitic Trichoderma DEMTkZ3A0 Strain and Changes in the Level of Auxin and Plant Resistance Markers in Wheat Seedlings Inoculated with this Strain Conidia

“…Trichoderma species are well known for the production of bioactive metabolites that play an important role in the mycoparasitic or entomopathogenic lifestyles of the fungus and in auto-regulatory processes in mycoparasitism/competition and interaction with the plant, e.g., the induction of resistance in plant hosts [18]. The Trichoderma species attach to the hyphae of the fungal or oomycete host, creates a coil around the host hyphae, forms structures similar to hooks, appressoria, or papillae, and penetrates the cell wall (CW) by the production of CWDEs [6,19,20]. Interestingly, the Trichoderma spp.…”

“…strains are mesophilic with the greatest saprophytic activity from 15 to 21 °C [40,85]. Various mechanisms of Trichoderma strains action have already been reported [6,15,16,17,20,28,41] but the literature on strains combining mechanisms, such as mycoparasitism, phytohormone and ACC deaminase synthesis, root colonization and induction of plant resistance and at the same time about the interrelationship of these mechanisms, is still very limited.…”

Antagonistic effect of Trichoderma isolates on Sclerotium rolfsii

“…As reported in present study, inhibition of S. rolfsii in dual culture plate experiment can be attributed to more rapidly growing ability of Trichoderma species and secretion of toxic extra cellular compounds such as antibiotics and cell wall degrading enzymes, i.e. β-1,3-glucanases, chitinases and proteases (Howell, 2003;Gajera et al, 2012). During mycoparasitic activity, these enzymes lyse hyphal cell wall of pathogens.…”