title: Plant Growth Promotion by Volatile Organic Compounds Produced byBacillus subtilisSYST2.
abstract: Bacterial volatiles play a significant role in promoting plant growth by regulating the synthesis or metabolism of phytohormones.In vitroand growth chamber experiments were conducted to investigate the effect of volatile organic compounds (VOCs) produced by the plant growth promoting rhizobacteriumBacillus subtilisstrain SYST2 on hormone regulation and growth promotion in tomato plants. We observed a significant increase in plant biomass under both experimental conditions; we observed an increase in photosynthesis and in the endogenous contents of gibberellin, auxin, and cytokinin, while a decrease in ethylene levels was noted. VOCs emitted by SYST2 were identified through gas chromatography-mass spectrometry analysis. Of 11 VOCs tested in glass jars containing plants in test tubes, only two, albuterol and 1,3-propanediole, were found to promote plant growth. Furthermore, tomato plants showed differential expression of genes involved in auxin (SlIAA1. SlIAA3), gibberellin (GA20ox-1), cytokinin (SlCKX1), expansin (Exp2, Exp9. Exp 18), and ethylene (ACO1) biosynthesis or metabolism in roots and leaves in response toB. subtilisSYST2 VOCs. Our findings suggest that SYST2-derived VOCs promote plant growth by triggering growth hormone activity, and provide new insights into the mechanism of plant growth promotion by bacterial VOCs.
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Hafiz A S
authors.initials: HA
authors.lastname: Tahir
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wu
authors.affiliation: Jiangsu Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University Nanjing, China.
authors.forename: Waseem
authors.initials: W
authors.lastname: Raza
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Alwina
authors.initials: A
authors.lastname: Hanif
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Massawe V
authors.initials: MV
authors.lastname: Colman
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Integrated Management of Diseases and Pests, Ministry of Education Nanjing, China.
authors.forename: Xuewen
authors.initials: X
authors.lastname: Gao
keywords: 1; 3-propanediole; Bacillus subtilis SYST2; albuterol; bacterial VOCs; growth promotion; phytohormones