title: Native isolate of Trichoderma: a biocontrol agent with unique stress tolerance properties.
abstract: Species of Trichoderma are widely recognized for their biocontrol abilities, but seldom studied collectively, for their plant growth promotion, abiotic stress tolerance and bioremediation properties. Our study is a concentrated effort to establish the potential of native isolate Trichoderma harzianum KSNM (T103) to tolerate biotic (root pathogens) and abiotic stresses [high salt (100-1000 mM); heavy metal (chromium, nickel and zinc: 1-10 mM); pesticides: malathion (100-600 ppm), carbofuran (100-600 ppb)], along with its ability to support plant growth. In vitro growth promotion assays with T103 treated Vigna radiata, Vigna mungo and Hordeum vulgare confirmed 'non-species specific' growth promotion effects of T103. At lower metal concentration, T103 treatment was found to completely negate the impact of metal stress [60 % increase in radicle length (RL) with no significant decrease in %germination (%G)]. Even at 10 mM metal, T103 inoculation gave 80 % increase in %G and >50 % increase in RL. In vitro experiments confirmed high metal reduction capacity (47 %-Cr, 35 %-Ni and 42 %-Zn) of T103 at concentrations as high as 4 mM. At maximum residual concentrations of malathion (440 ppm) and carbofuran (100 ppb) reported in agricultural soils, T103 maintained 80 and 100 % survivability, respectively. T103 treatment has improved %G and RL in all three hosts challenged with pesticide. Isolate T103 was found to effectively suppress growth of three major root pathogens: Macrophomina phaseolina (65.83 %) followed by Sclerotium rolfsii (19.33 %) and Fusarium oxysporum (19.18 %). In the light of these observations, native T. harzianum (T103) seems to be a competent biocontrol agent for tropical agricultural soils contaminated with residual pesticides and heavy metals.
authors.affiliation: Plant and Microbial Biotechnology Group, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, Uttar Pradesh, 201309, India.
authors.forename: N
authors.initials: N
authors.lastname: Mishra
authors.affiliation: Plant and Microbial Biotechnology Group, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, Uttar Pradesh, 201309, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Khan
authors.affiliation: Plant and Microbial Biotechnology Group, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, Uttar Pradesh, 201309, India. krishna.sundari@jiit.ac.in.
authors.forename: S Krishna
authors.initials: SK
authors.lastname: Sundari
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D001673:Biodegradation, Environmental; D019216:Metals, Heavy / Q000009:adverse effects; D054712:Salinity; D012988:Soil Microbiology; D013312:Stress, Physiological; D014242:Trichoderma / Q000254:growth & development* / Q000302:isolation & purification*
chemical_list: D019216:Metals, Heavy
keywords: Biocontrol agent; Pesticide tolerance; Salt stress; Tolerance to heavy metal; Trichoderma