title: Application of sonication in combination with vacuum infiltration enhances the Agrobacterium-mediated genetic transformation in Indian soybean cultivars.
abstract: Soybean is a recalcitrant crop to Agrobacterium-mediated genetic transformation. Development of highly efficient, reproducible, and genotype-independent transformation protocol is highly desirable for soybean genetic improvement. Hence, an improved Agrobacterium-mediated genetic transformation protocol has been developed for cultivar PK 416 by evaluating various parameters including Agrobacterium tumefaciens strains (LBA4404, EHA101, and EHA105 harboring pCAMBIA1304 plasmid), sonication duration, vacuum infiltration pressure, and vacuum duration using cotyledonary node explants of soybean prepared from 7-day-old seedlings. The transformed plants were successfully developed through direct organogenesis system. Transgene expression was assessed by GUS histochemical and gfp visual assays, and integration was analyzed by PCR and Southern blot hybridization. Among the different combinations and durations evaluated, a maximum transformation efficiency of 18.6 % was achieved when the cotyledonary node explants of cv. PK 416 were sonicated for 20 s and vacuum infiltered for 2 min at 250 mmHg in A. tumefaciens EHA105 suspension. The amenability of the standardized protocol was tested on four more soybean cultivars JS 90-41, Hara Soy, Co 1, and Co 2 in which all the cultivars responded favorably with transformation efficiency ranging from 13.3 to 16.6 %. The transformation protocol developed in the present study would be useful to transform diverse soybean cultivars with desirable traits.
authors.affiliation: Department of Biotechnology & Genetic Engineering, School of Biotechnology, Bharathidasan University, Tiruchirappalli, 620024,, Tamil Nadu, India.
authors.forename: Muthukrishnan
authors.initials: M
authors.lastname: Arun
authors.forename: Kondeti
authors.initials: K
authors.lastname: Subramanyam
authors.forename: Thankaraj Salammal
authors.initials: TS
authors.lastname: Mariashibu
authors.forename: Jeevaraj
authors.initials: J
authors.lastname: Theboral
authors.forename: Ganeshan
authors.initials: G
authors.lastname: Shivanandhan
authors.forename: Markandan
authors.initials: M
authors.lastname: Manickavasagam
authors.forename: Andy
authors.initials: A
authors.lastname: Ganapathi
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D018548:Cotyledon / Q000235:genetics*; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007194:India; D019868:Kanamycin Kinase / Q000235:genetics / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000737:chemistry* / Q000378:metabolism; D036226:Seedlings / Q000235:genetics; D013010:Sonication; D013025:Glycine max / Q000235:genetics*; D014170:Transformation, Genetic; D014618:Vacuum
chemical_list: D049452:Green Fluorescent Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C063242:hygromycin-B kinase; D019868:Kanamycin Kinase