title: Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea.
abstract: The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20°C to 40°C, pH range of 7-11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40) but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40), hydrocyanic acid (except VAI-7 and VAI-40), indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea.
authors.affiliation: Centre for Biotechnology, Jawaharlal Nehru Technological University, Kukatpally 500072, Telangana, India; International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502324, Telangana, India.
authors.forename: M
authors.initials: M
authors.lastname: Sreevidya
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502324, Telangana, India. Electronic address: s.gopalakrishnan@cgiar.org.
authors.forename: S
authors.initials: S
authors.lastname: Gopalakrishnan
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502324, Telangana, India.
authors.forename: H
authors.initials: H
authors.lastname: Kudapa
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502324, Telangana, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Varshney
mesh_terms: D039903:Actinobacteria / Q000254:growth & development* / Q000378:metabolism; D029863:Cicer / Q000254:growth & development*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism; D012987:Soil; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012965:Sodium Chloride
keywords: Actinomycetes; Biocontrol; Chickpea; Gene expression; PGP; Streptomyces