title: Euphorbia milii-Endophytic Bacteria Interactions Affect Hormonal Levels of the Native Host Differently Under Various Airborne Pollutants.
abstract: This study was conducted to assess the effect of plant-native endophytic bacteria interactions on indole-3-acetic acid (IAA), ethylene levels, and hormonal balance of Euphorbia milii under different airborne pollutants. IAA levels and airborne formaldehyde removal by E. milii enhanced when inoculated with endophytic isolates. However, one isolate, designated as root endophyte 4, with the highest levels of IAA production individually, declined gaseous formaldehyde removal of plant, since it disturbed hormonal balance of E. milii, leading to IAA levels higher than physiological concentrations, which stimulated ethylene biosynthesis and stomatal closure under light conditions. However, plant-root endophyte 4 interactions favored airborne benzene removal, since benzene was more phytotoxic and the plant needed more IAA to protect against benzene phytotoxicity. As trimethylamine (TMA) was not toxic, it did not affect plant-endophyte interactions. Therefore, IAA levels of root endophyte 4-inoculated E. milii was not significantly different from a noninoculated one. Under mixed-pollutant stress (formaldehyde, benzene, TMA), root endophyte 4-inoculated E. milii removed benzene at the lowest rate, since benzene was the most phytotoxic pollutant with the greatest molecular mass. However, TMA (with greater molecular mass) was removed faster than formaldehyde due to higher phytotoxicity of formaldehyde. Plant-endophyte interactions were affected differently under various airborne pollutants.
authors.affiliation: 1 School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Khaksar
authors.affiliation: 1 School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.|2 Faculty of Mathematics and Natural Sciences, Brawijaya University, Malang 65145, Indonesia; and.
authors.forename: Dian
authors.initials: D
authors.lastname: Siswanto
authors.affiliation: 3 Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi.
authors.forename: Chairat
authors.initials: C
authors.lastname: Treesubsuntorn
authors.affiliation: 1 School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
authors.forename: Paitip
authors.initials: P
authors.lastname: Thiravetyan
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001554:Benzene / Q000633:toxicity; D060026:Endophytes; D005030:Ethylenes / Q000378:metabolism; D028481:Euphorbia / Q000382:microbiology* / Q000502:physiology; D005557:Formaldehyde / Q000633:toxicity; D007210:Indoleacetic Acids / Q000378:metabolism; D008744:Methylamines / Q000633:toxicity; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology / Q000502:physiology; D054046:Plant Stomata / Q000382:microbiology / Q000502:physiology; D013312:Stress, Physiological
chemical_list: D000393:Air Pollutants; D005030:Ethylenes; D007210:Indoleacetic Acids; D008744:Methylamines; D010937:Plant Growth Regulators; D005557:Formaldehyde; C030737:indoleacetic acid; C036216:ethylene; D001554:Benzene; C023336:trimethylamine