title: Expression of an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene in psychrotolerant bacteria modulates ethylene metabolism and cold induced genes in tomato under chilling stress.
abstract: The role of stress induced ethylene under low temperature stress has been controversial and hitherto remains unclear. In the present study, 1-aminocyclopropane-1-carboxylate deaminase (ACCD) gene, acdS expressing mutant strains were generated from ACCD negative psychrotolerant bacterial strains Flavobacterium sp. OR306 and Pseudomonas frederiksbergensis OS211, isolated from agricultural soil during late winter. After transformation with plasmid pRKACC which contained the acdS gene, both the strains were able to exhibit ACCD activity in vitro. The effect of this ACCD under chilling stress with regards to ethylene was studied in tomato plants inoculated with both acdS expressing and wild type bacteria. On exposing the plants to one week of chilling treatment at 12/10 °C, it was found that stress ethylene, ACC accumulation and ACO activity which are markers of ethylene stress, were significantly reduced in plants inoculated with the acdS gene transformed mutants. In case of plants inoculated with strain OS211-acdS, ethylene emission, ACC accumulation and ACO activity was significantly reduced by 52%, 75.9% and 23.2% respectively compared to uninoculated control plants. Moreover, expression of cold induced LeCBF1 and LeCBF3 genes showed that these genes were significantly induced by the acdS transformed mutants in addition to reduced expression of ethylene-responsive transcription factor 13 (ETF-13) and ACO genes. Induced expression of LeCBF1 and LeCBF3 in plants inoculated with acdS expressing mutants compared to wild type strains show that physiologically evolved stress ethylene and its transcription factors play a role in regulation of cold induced genes as reported earlier in the literature.
authors: Department of Environmental and Biological Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors: Parthiban
authors: P
authors: Subramanian
authors: Department of Environmental and Biological Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors: Ramasamy
authors: R
authors: Krishnamoorthy
authors: Department of Environmental and Biological Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors: Mak
authors: M
authors: Chanratana
authors: Department of Environmental and Biological Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors: Kiyoon
authors: K
authors: Kim
authors: Department of Environmental and Biological Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea. Electronic address: tomsa@chungbuk.ac.kr.
authors: Tongmin
authors: T
authors: Sa
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000598:Amino Acids, Cyclic / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D019755:Carbon-Carbon Lyases / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics; D005030:Ethylenes / Q000378:metabolism*; D005417:Flavobacterium / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D005798:Genes, Bacterial; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism; D012988:Soil Microbiology; D013312:Stress, Physiological / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000598:Amino Acids, Cyclic; D005030:Ethylenes; D010940:Plant Proteins; D014157:Transcription Factors; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; C033634:1-aminocyclopropane-1-carboxylate deaminase; D019755:Carbon-Carbon Lyases
keywords: CRT-repeat binding factors; Ethylene response factors; Low-temperature stress; Plant growth