title: Bacterial endophyte Sphingomonas sp. LK11 produces gibberellins and IAA and promotes tomato plant growth.
abstract: Plant growth promoting endophytic bacteria have been identified as potential growth regulators of crops. Endophytic bacterium, Sphingomonas sp. LK11, was isolated from the leaves of Tephrosia apollinea. The pure culture of Sphingomonas sp. LK11 was subjected to advance chromatographic and spectroscopic techniques to extract and isolate gibberellins (GAs). Deuterated standards of [17, 17-(2)H2]-GA4, [17, 17-(2)H2]-GA9 and [17, 17-(2)H2]-GA20 were used to quantify the bacterial GAs. The analysis of the culture broth of Sphingomonas sp. LK11 revealed the existence of physiologically active gibberellins (GA4: 2.97 ± 0.11 ng/ml) and inactive GA9 (0.98 ± 0.15 ng/ml) and GA20 (2.41 ± 0.23). The endophyte also produced indole acetic acid (11.23 ± 0.93 μM/ml). Tomato plants inoculated with endophytic Sphingomonas sp. LK11 showed significantly increased growth attributes (shoot length, chlorophyll contents, shoot, and root dry weights) compared to the control. This indicated that such phyto-hormones-producing strains could help in increasing crop growth.
authors.affiliation: Department of Biological Sciences and Chemistry, University of Nizwa, Nizwa, Oman.
authors.forename: Abdul Latif
authors.initials: AL
authors.lastname: Khan
authors.forename: Muhammad
authors.initials: M
authors.lastname: Waqas
authors.forename: Sang-Mo
authors.initials: SM
authors.lastname: Kang
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Harrasi
authors.forename: Javid
authors.initials: J
authors.lastname: Hussain
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Rawahi
authors.forename: Salima
authors.initials: S
authors.lastname: Al-Khiziri
authors.forename: Ihsan
authors.initials: I
authors.lastname: Ullah
authors.forename: Liaqat
authors.initials: L
authors.lastname: Ali
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Jung
authors.forename: In-Jung
authors.initials: IJ
authors.lastname: Lee
mesh_terms: D002734:Chlorophyll / Q000096:biosynthesis; D060026:Endophytes / Q000302:isolation & purification / Q000378:metabolism; D005875:Gibberellins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000254:growth & development* / Q000382:microbiology; D063245:Plant Development; D018515:Plant Leaves / Q000382:microbiology; D018517:Plant Roots / Q000254:growth & development; D016133:Polymerase Chain Reaction; D020578:Sphingomonas / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D031304:Tephrosia / Q000382:microbiology*
chemical_list: D005875:Gibberellins; D007210:Indoleacetic Acids; D002734:Chlorophyll; C030737:indoleacetic acid