title: Psychrotolerant Endophytic Pseudomonas sp. Strains OB155 and OS261 Induced Chilling Resistance in Tomato Plants (Solanum lycopersicum Mill.) by Activation of Their Antioxidant Capacity.
abstract: Studies on chilling stress damage and its mitigation through microorganisms in members of family Solanaceae is limited, despite their economic importance. We studied chilling stress alleviation in tomato plants colonized by psychrotolerant bacterial strains Pseudomonas vancouverensis OB155-gfp and P. frederiksbergensis OS261-gfp. Log phase cultures of bacterial strains were coated on surface-sterilized seeds (bacterization) before sowing and nonbacterized (control) seeds were coated with sterile bacterial growth medium. All plants were grown at temperatures of 30 and 25°C and at the end of 4 weeks, chilling treatment (12 and 10°C) was imposed for 1 week on half of the bacterized and control plants. Under normal conditions (30 and 25°C), no significant difference was observed in antioxidant activity, proline accumulation, and expression of cold acclimation genes in tomato leaf tissues of both control and bacterized plants. However, plants exposed to temperatures of 12 and 10°C were found to decrease in robustness and nutrient uptake, accompanied by increased membrane damage. Chilling resistance in bacterized plants was evident from reduced membrane damage and reactive oxygen species levels, improved antioxidant activity in leaf tissues, and high expression of cold acclimation genes LeCBF1 and LeCBF3 compared with control plants. Confocal microscopy confirmed effective colonization and intercellular localization of cold-adapted bacterial strains OB155-gfp and OS261-gfp.
authors.affiliation: 1 Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea;
authors.forename: Parthiban
authors.initials: P
authors.lastname: Subramanian
authors.affiliation: 2 School of Bio Sciences and Technology, VIT University, Vellore, Tamil Nadu 632014, India;
authors.forename: Anbazhagan
authors.initials: A
authors.lastname: Mageswari
authors.affiliation: 1 Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea;
authors.forename: Kiyoon
authors.initials: K
authors.lastname: Kim
authors.affiliation: 3 Department of Industrial Plant Science and Technology, Chungbuk National University.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lee
authors.affiliation: 1 Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea;
authors.forename: Tongmin
authors.initials: T
authors.lastname: Sa
mesh_terms: D000064:Acclimatization; D000975:Antioxidants / Q000378:metabolism*; D018533:Biomass; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D054884:Host-Pathogen Interactions; D018551:Solanum lycopersicum / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D011549:Pseudomonas / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D017382:Reactive Oxygen Species