Phytohormone Production Profiles in Trichoderma Species and Their Relationship to Wheat Plant Responses to Water Stress (original) (raw)
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Trichoderma as an efficacious bioagent for combating biotic and abiotic stresses of wheat-A review
Agricultural Reviews
Several environmental stresses are the major hindrances in achieving the attainable yield in wheat crop. The actual losses due to biotic stresses is estimated in the range of 26-29%, however, abiotic stresses have more adverse effects on crop yield and are responsible for about 70% of yield reduction worldwide. Agrochemicals are widely considered as an effective management strategy for wheat crop diseases and insect pests but they adversely affect the human and animal health due to accumulation of chemical residues in the soil, plant tissues and grains. Hence, there is a need for alternate management strategies to protect crop plants against various stresses. Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to agrochemicals for overcoming the biotic and abiotic stresses. The importance of Trichoderma in alleviating the myriad of biotic and abiotic stresses of wheat is discussed in this review article.
Molecular Plant-Microbe Interactions, 2012
Some plant-symbiotic strains of the genus Trichoderma colonize roots and induce profound changes in plant gene expression that lead to enhanced growth, especially under biotic and abiotic stresses. In this study, we tested the hypothesis that one of the protective mechanisms enhanced by T. harzianum T22 colonization is the antioxidant defense mechanism. Having established that strain T22 modulates the expression of the genes encoding antioxidant enzymes, the status of antioxidant defense of tomato seedlings in response to colonization by T22 and water deficit was investigated. Total ascorbate or glutathione levels were not affected by either stimuli, but under water deficit, antioxidant pools became more oxidized (lower ratios of reduced to oxidized forms), whereas colonized plants maintained redox state as high as or higher than unstressed and untreated plants. The enhanced redox state of colonized plants could be explained by their higher activity of ascorbate and glutathione-recy...
Journal of Plant Physiology, 2018
Dichlorophenoxyacetic acid (2,4-D) is among the most commonly used herbicides applied for weed control during wheat cultivation. However, its application could affect wheat growth. The present study investigates the effect of the ascomycetous fungus Trichoderma harzianum on lipid peroxidation, phospholipids, signaling lipids and phospholipase D in the seedlings of wheat (Triticum aestivum L.) treated with 2,4-D (2.5 mg L-1). In the group of 4-day-old seedlings exposed to the herbicide, increased lipid peroxidation and inhibition of growth were observed in shoots and roots. Moreover, elevated levels of oxylipins were noted. Among them, the amount of 13-HOTrE oxygenated from linolenic acid (18:3) increased the most significantly. Concurrently, in the seedlings inoculated with T. harzianum, growth was stimulated when the level of phosphatidylcholine (PC) increased. Moreover, in wheat seedlings treated with 2,4-D and T. harzianum, the level of lipid peroxidation was similar to that in the control and there was no increase observed in oxylipins and phospholipase D activity. T. harzianum might have partly alleviated the toxic effect of 2,4-D on wheat seedlings.
Frontiers in Plant Science
Waterlogging stress (WS) induces ethylene (ET) and polyamine (spermine, putrescine, and spermidine) production in plants, but their reprogramming is a decisive element for determining the fate of the plant upon waterlogging-induced stress. WS can be challenged by exploring symbiotic microbes that improve the plant’s ability to grow better and resist WS. The present study deals with identification and application of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing fungal endophyte Trichoderma asperellum (strain MAP1), isolated from the roots of Canna indica L., on wheat growth under WS. MAP1 positively affected wheat growth by secreting phytohormones/secondary metabolites, strengthening the plant’s antioxidant system and influencing the physiology through polyamine production and modulating gene expression. MAP1 inoculation promoted yield in comparison to non-endophyte inoculated waterlogged seedlings. Exogenously applied ethephon (ET synthesis inducer) and 1-aminocycl...
Abiotic plant stress mitigation by Trichoderma species
Soil ecology letters, 2024
• Ascomycetes of the genus Trichoderma are beneficial fungi that promote plant growth. • Several fungal species can mitigate abiotic stress in plants. • Trichoderma spp. induce salt stress tolerance and drought protection in plants. • Soil contamination by heavy metals can be bioremediated by Trichoderma. • Trichoderma can detoxify pesticides and other pollutants in soils. Plants drive both carbon and nitrogen cycling and mediate complex biotic interactions with soil microorganisms. Climate change and the resulting temperature variations, altered precipitation, and water shortages in soils, affect the performance of plants. Negative effects of abiotic stress are reflected in changes of plant morphology associated with biochemical alterations and inadequate adaptation to rapid ecological change. Accumulation of chemical agents, derived from pesticides, salinity due to chemical fertilization, and accumulation of heavy metals, are recurrent problems in agricultural soils. Trichoderma spp. are soil fungi interacting with roots and in this way helping plants to cope with abiotic stresses by increasing root branching, shoot growth and productivity. In part, such fungal effects on the host plant are consequences of the activation of fine-tuned molecular mechanisms mediated by phytohormones, by profound biochemical changes that include production of osmolytes, by the activity of the redox-enzymatic machinery, as well by as complex processes of detoxification. Here, we summarize the most recent advances regarding the beneficial effects of Trichoderma in mitigating the negative effects on plant performance caused by different environmental and chemical factors associated with global change and agricultural practices that provoke abiotic stress. Additionally, we present new perspectives and propose further research directions in the field of Trichoderma-plant interactions when the two types of organism cooperate.
European Journal of Plant Pathology, 2011
Trichoderma harzianum is an effective biocontrol agent against the devastating plant pathogen Rhizoctonia solani. Despite its wide application in agriculture, the mechanisms of biocontrol are not yet fully understood. Mycoparasitism and antibiosis are suggested, but may not be sole cause of disease reduction. In the present study, we investigated the role of oxidant-antioxidant metabolites in the root apoplast of sunflower challenged by R. solani in the presence/absence of T. harzianum NBRI-1055. Analysis of oxidative stress response revealed a reduction in hydroxyl radical concentration (• OH; 3.6 times) at 9 days after pathogen inoculation (dapi), superoxide anion radical concentration (O 2 •− ; 4.1 times) at 8 dapi and hydrogen peroxide concentration (H 2 O 2 ; 2.7 times) levels at 7 dapi in plants treated with spent maize-cob formulation of T. harzianum NBRI-1055 (MCFT), as compared to pathogen-inoculated plants. The protection afforded by the biocontrol agent was associated with the accumulation of the ROS gene network: the catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and ascorbate peroxidase (APx), maximum activity of CAT (11.0 times) was observed at 8 dapi, SOD (7.0 times) at 7 dapi, GPx (5.4 times) and APx (8.1 times) at 7 dapi in MCFT-treated plants challenged with the pathogen. This was further supported by the inhibition of lipid and protein oxidation in Trichoderma-inoculated plants. MCFT stimulated the accumulation of secondary metabolites of phenolic nature that increased up to five-fold and also exhibited strong antioxidant activity at 8 dapi, eventually leading to the systemic accumulation of phytoalexins. These results suggest that T. harzianum-mediated biocontrol may be related to alleviating R. solani-induced oxidative stress.
International Journal of Molecular Sciences, 2019
Both hormonal balance and plant growth may be shaped by microorganisms synthesizing phytohormones, regulating its synthesis in the plant and inducing plant resistance by releasing elicitors from cell walls (CW) by degrading enzymes (CWDE). It was shown that the Trichoderma DEMTkZ3A0 strain, isolated from a healthy rye rhizosphere, colonized the rhizoplane of wheat seedlings and root border cells (RBC) and caused approximately 40% increase of stem weight. The strain inhibited (in over 90%) the growth of polyphagous Fusarium spp. (F. culmorum, F. oxysporum, F. graminearum) phytopathogens through a mechanism of mycoparasitism. Chitinolytic and glucanolytic activity, strongly stimulated by CW of F. culmorum in the DEMTkZ3A0 liquid culture, is most likely responsible for the lysis of hyphae and macroconidia of phytopathogenic Fusarium spp. as well as the release of plant resistance elicitors. In DEMTkZ3A0 inoculated plants, an increase in the activity of the six tested plant resistance m...
British Microbiology Research Journal, 2016
Aim: Determine the effect of different inoculum concentrations of T. harzianum from semi-arid soils on the activity of antioxidant enzymes of maize seedlings under water stress. Methods and Results: This study employed a three-factor factorial (3×4×4) design, arranged in a completely randomized design (CRD) with three replications. Three maize varieties (H614, H629 and H6210) were treated with four concentrations of T. harzianum (0, 1x10 5 , 1x10 7 and 1x10 10 spore/ml and thereafter grown under four osmotic potential regimes (0,-0.3,-0.6 and-0.9 MPa). Results from the study showed that T. harzianum had a significant effect on Superoxide dismutase (SOD) and catalase (CAT) activity of maize seedlings and did not enhance either maize seed germination or seedling growth. The activity of SOD and CAT was significantly enhanced by T. harzianum in all the three varieties of maize. Optimum SOD and CAT activity were recorded in seeds treated with 10 7 spores/ml of T. harzianum. Under normal growth conditions (0MPa), SOD and CAT activities were not enhanced by T. harzianum. However, under severe water stress (-0.9MPa), maximum activity of the enzymes was registered in all the three varieties of maize.