Agrobacterium-mediated transformation of rough lemon (Citrus jambhiri Lush) with yeast HAL2 gene

Abstract

Background: Rough lemon (Citrus jambhiri Lush.) is the most commonly used Citrus rootstock in south Asia. It is extremely sensitive to salt stress that decreases the growth and yield of Citrus crops in many areas worldwide. Over expression of the yeast halotolerant gene (HAL2) results in increasing the level of salt tolerance in transgenic plants. Results: Transformation of rough lemon was carried out by using Agrobacterium tumefaciens strains LBA4404 harboring plasmid pJRM17. Transgenic shoots were selected on kanamycin 100mgL-1 along with 250mgL-1 each of cefotaxime and vancomycin for effective inhibition of Agrobacterium growth. The Murashige and Skoog (MS) medium containing 200M acetoseryngone (AS) proved to be the best inoculation and co-cultivation medium for transformation. MS medium supplemented with 3mgL -1 of 6-benzylaminopurine (BA) showed maximum regeneration efficiency of the transformed explants. The final selection of the transformed plants was made on the basis of PCR and Southern blot analysis. Conclusion: Rough lemon has been successfully transformed via Agrobacterium tumefaciens with -glucuronidase (GUS) and HAL2. Various factors affecting gene transformation and regeneration efficiency were also investigated. © 2012 Ali et al.;licensee BioMed Central Ltd.