title: Induced ectopic expression of At-CBF1 in marker-free transgenic tomatoes confers enhanced chilling tolerance.
abstract: In an attempt to improve chilling stress tolerance, an Arabidopsis C-repeat binding factor 1 (At-CBF1) gene driven by the inducible promoter RD29A was co-transferred into tomato var. Shalimar. Marker (NPTII)-free transgenic were obtained in T(1) generation because of unlinked integration of CBF1 and NPTII genes. Reverse transcription-polymerase chain reaction confirmed the expression of CBF1 in T(1) transgenic lines. Study of expression pattern in T(1) transgenic line showed a gradual increase with increasing chilling stress period and also confirmed the reversibility of expression on removal of stress. The transgenic plants exhibited no morphological and agronomical differences as compared to non-transformed plants. When young transgenic plants were exposed to chilling stress (4°C) for 3 days, increased survival (50%) was observed in transgenic lines than non-transformed plants (10%). Transgenic plants subjected to the chilling stress showed a significant decrease in membrane injury index and lipid peroxidation and also increased significantly free proline content in the leaf tissues as compared to non-transformed plants. Thus, these findings indicate that marker-free transgenic tomato plants expressing Arabidopsis CBF1 gene provided protection and conferred cold tolerance to transgenic tomato without any phenotypic variation.
authors.affiliation: Molecular Biology and Genetic Engineering Division, Defence Institute of Bio-Energy Research, Haldwani 263 139, Uttarakhand, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Singh
authors.forename: Meenal
authors.initials: M
authors.lastname: Rathore
authors.forename: Danswrang
authors.initials: D
authors.lastname: Goyary
authors.forename: Rupesh Kumar
authors.initials: RK
authors.lastname: Singh
authors.forename: Sivalingam
authors.initials: S
authors.lastname: Anandhan
authors.forename: Dinesh K
authors.initials: DK
authors.lastname: Sharma
authors.forename: Zakwan
authors.initials: Z
authors.lastname: Ahmed
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015139:Blotting, Southern; D020090:Chromosome Segregation / Q000235:genetics; D003080:Cold Temperature; D018744:DNA, Plant / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005819:Genetic Markers; D018745:Genome, Plant / Q000235:genetics; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology*; D018515:Plant Leaves / Q000235:genetics; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C104387:CBF1 protein, Arabidopsis; D018744:DNA, Plant; D005819:Genetic Markers; D015534:Trans-Activators