Bio-protective microbial agents from rhizosphere eco-systems trigger plant defense responses provide protection against sheath blight disease in rice (Oryza sativa L.).
Sheath blight of rice (Oryza sativa L.) caused by Rhizoctonia solani is a major disease and attempts are being made to develop microbe based technologies for biocontrol of this pathogen. However, the mechanisms of biocontrol are not fully understood and still require indepth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed at deciphering the mechanisms of biocontrol of sheath blight of rice employing Pseudomonas fluorescens and Trichoderma harzianum as model agents for biocontrol. Initially 25, 5 and 5 strains of P. fluorescens, T. viride and T. harzianum, respectively, were screened for their biocontrol potential. Out of which, six strains with higher value of percent inhibition of fungal mycelium in dual plate assay were selected. The role of P. fluorescens, T. viride and T. harzianum were investigated in induction and bioaccumulation of natural antioxidants, defence-related biomolecules and other changes in plant which lead not only to growth promotion but also protection from pathogenic stress conditions in rice. The two most promising strains, P. fluorescens PF-08 and T. harzianum UBSTH-501 selected on the basis of in planta evaluation, when applied individually or in combination, significantly enhanced the accumulation of defence-related biomolecules, enzymes and exhibited biocontrol potential against R. solani. A modified/newly developed delivery system was applied for the first time in the experiments involving inoculation of plants with both bioagents, viz. P. fluorescens PF-08 and T. harzianum UBSTH-501. Results suggested that application of P. fluorescens PF-08 and T. harzianum UBSTH-501 alone or in combination, not only helps in control of the disease but also increases plant growth along with reduction in application of toxic chemical pesticides.
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India. Electronic address: udaiars.nbaim@gmail.com.
Udai B
UB
Singh
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Deepti
D
Malviya
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Wasiullah
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Shailendra
S
Singh
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Jatindra K
JK
Pradhan
Department of Plant Pathology, College of Agriculture, Narendra Dev University of Agriculture and Technology, Kumarganj, Faizabad 224229, India.
Bhanu P
BP
Singh
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Manish
M
Roy
Department of Bioscience, Faculty of Applied Science, Integral University, Lucknow 226026, India.
Mohd
M
Imram
Department of Bioscience, Faculty of Applied Science, Integral University, Lucknow 226026, India.
Neelam
N
Pathak
Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi 110012, India.
B M
BM
Baisyal
Department of Mycology and Plant Pathology (Krishi Vigyan Kendra), Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India.
Jai P
JP
Rai
Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221 005, India.
B K
BK
Sarma
ICAR-Directorate of Seed Research, Kushmaur, Maunath Bhanjan 275103, India.
Rajiv K
RK
Singh
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
P K
PK
Sharma
Division of Soil Biology, Indian Institute of Soil Science, Nabibagh, Berasia road, Bhopal 462038, India.
Saman Deep
SD
Kaur
Division of Soil Biology, Indian Institute of Soil Science, Nabibagh, Berasia road, Bhopal 462038, India.
M C
MC
Manna
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Sushil K
SK
Sharma
ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275103, India.
Arun K
AK
Sharma
D000898:Antibiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics; D061046:Biological Control Agents; D005658:Fungi / Q000145:classification / Q000235:genetics; D018525:Germination; D054884:Host-Pathogen Interactions; D064307:Microbiota; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology*; D058441:Rhizosphere; D036226:Seedlings
D061046:Biological Control Agents
Defence-related biomolecules; Induced systemic resistance (ISR); Pseudomonas; Rhizosphere; Signalling biomolecules; Trichoderma