Isolation and identification of Amycolatopsis sp. strain 1119 with potential to improve cucumber fruit yield and induce plant defense responses in commercial greenhouse

• Published in: Plant and soil Vol. 468; no. 1-2; pp. 125 - 145
• Main Authors: Alipour Kafi, Sahar, Karimi, Ebrahim, Akhlaghi Motlagh, Mahmood, Amini, Zahra, Mohammadi, Ali, Sadeghi, Akram
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2021; Springer; Springer Nature B.V
• Subjects: Actinobacteria; Actinomycetes; Agriculture; Amycolatopsis; Analysis; Antioxidants; Biological control; Biomedical and Life Sciences; Corn; Crop yield; Crop yields; Cucumbers; Damping; Damping-off; Defense mechanisms; Ecology; Fruits; Fungal diseases; Fungicides; Gene expression; Genes; Greenhouses; Growth; Identification and classification; Life Sciences; Liquid oxygen; Methods; Phytopathogenic fungi; Phytophthora capsici; Plant defenses; Plant diseases; Plant Physiology; Plant Sciences; Properties; Regular Article; Rhizosphere; Separation (Technology); Soil Science & Conservation; Strains (organisms); Streptomyces; Transcription; Iran; Damping-off; PGPB; Fruit quality; Biocontrol
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-021-05097-3

Background and aims The application of chemical fungicides is the first strategy to control plant fungal diseases. This approach is highly polluting for the environment and affects human health. The artificial introduction of beneficial rhizobacteria into the soil can be an economical and practical way to control phytopathogenic fungi in commercial greenhouses. Here, we recount the travel of a rare Actinomycete ( Amycolatopsis strain 1119) from a maize field to a commercial cucumber greenhouse. Methods and results Culturable bacteria from rhizosphere and bulk soils of dicot and monocot crops were isolated and screened. About 20% of the representative colonies showed Actinobacteria appearance. 106 Actinobacteria that had antagonistic activity against Phytophthora capsici and were able to produce IAA-like molecules were selected for further analysis. Two Streptomyces strains (432 and 615) and 2 Amycolatopsis strains (3513 and 1119) that showed a positive effect on plant growth in greenhouse conditions were selected to evaluate the biocontrol potential. Strains 432, 3513, 615 and 1119 controlled incidence of the damping-off by 65%, 42%, 83% and 100% respectively. Application of strain 1119 under commercial greenhouse conditions resulted in an increase in fruit yield (20%) and a decrease in fruit nitrate content (70%). Increased antioxidant enzymes activity and increased LOX and APX transcription and also, increased expression of two genes PR1-1a and GLU (SAR genes) showed that strain 1119 could induce both ISR and SAR in cucumber without pathogen exposure. Conclusion Our results demonstrate that the  Amycolatopsis  strain 1119 has a great potential to be used as an active principle for bio-inoculant development because of the ability to improve cucumber fruit yield and induce plant defense responses in a commercial greenhouse.