title: Isolation and evaluation of proteolytic actinomycete isolates as novel inducers of pearl millet downy mildew disease protection.
abstract: Native endophytic actinomycetes isolated from pearl millet roots were examined for their efficacy to protect pearl millet against downy mildew. Nineteen of 39 isolates were found to be proteolytic, of which 7 strains could directly suppress the sporangium formation of Sclerospora graminicola, the pearl millet downy mildew pathogen. Thus, mycelial suspensions containing either spores or cell-free extract of these 7 isolates were used for seed-coating and -soaking treatments to test for their induction of downy mildew resistance. Results indicated that seed-coating overall provided better protection to downy mildew than seed-soaking. In both treatments, the tested isolates demonstrated differential abilities in downy mildew disease protection, with Streptomyces griseus SJ_UOM-07-09 and Streptosporangium roseum SJ_UOM-18-09 showing the highest protection rates. Additionally, the levels of disease protection conferred by the actinomycetes were just slightly lower than that of the systemic fungicide Apron, suggesting their effectiveness. Further studies revealed that the more rapid root colonization by SJ_UOM-18-09 resulted in faster and higher induced resistance in comparison with SJ_UOM-07-09 under greenhouse conditions, indicating that SJ_UOM-18-09 was superior than SJ_UOM-07-09 in inducing resistance. Results from this study provide comprehensive information on biocontrol functions of SJ_UOM- 18-09 with great potential to control downy mildew disease in pearl millet.
authors: Plant Healthcare and Diagnostic Center, Department of Studies in Biotechnology and Microbiology, Karnatak University, Dharwad 580 003, Karnataka, India.
authors: Sudisha
authors: S
authors: Jogaiah
authors: Plant Healthcare and Diagnostic Center, Department of Studies in Biotechnology and Microbiology, Karnatak University, Dharwad 580 003, Karnataka, India.
authors: Mahantesh
authors: M
authors: Kurjogi
authors: Department of Studies and Research in Environmental Sciences, Tumkur University, Tumkur 572103, Karnataka, India.
authors: Sharathchandra Ramasandra
authors: SR
authors: Govind
authors: Downy Mildew Research Laboratory, Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysore 570006, India.
authors: Shekar Shetty
authors: SS
authors: Huntrike
authors: Plant Healthcare and Diagnostic Center, Department of Studies in Biotechnology and Microbiology, Karnatak University, Dharwad 580 003, Karnataka, India.
authors: Vedamurthy Ankala
authors: VA
authors: Basappa
authors: Plant Abiotic Stress Research Group &Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.|Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
authors: Lam-Son Phan
authors: LS
authors: Tran
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D060467:Disease Resistance; D005659:Fungicides, Industrial / Q000494:pharmacology; D031782:Pennisetum / Q000254:growth & development* / Q000382:microbiology; D044742:Peronospora / Q000187:drug effects / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D059748:Proteolysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012639:Seeds / Q000254:growth & development / Q000382:microbiology
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005659:Fungicides, Industrial; D012336:RNA, Ribosomal, 16S