Genetic Engineering and Gene Transformation
Saeed Soheilivand; Amir Mousavi; Mohammadreza Safarnejad
Abstract
Sour lime (Citrus aurantifolia L.) is one of the most important woody plants is widely known for its recalcitrance to genetic transformation. We aimed herein to evaluate effective factors influencing the transformation efficiency and the reduction of chimeric transgenic shoots in sour lime. Epicotyl ...
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Sour lime (Citrus aurantifolia L.) is one of the most important woody plants is widely known for its recalcitrance to genetic transformation. We aimed herein to evaluate effective factors influencing the transformation efficiency and the reduction of chimeric transgenic shoots in sour lime. Epicotyl and internode explants were genetically transformed with different Agrobacterium tumefaciens strains e.g., LBA4404, GV3850, and GV3101, harboring the vectors pBI121 and pCAMBIA3301 containing β-glucuronidase (GUS) as a reporter gene. The effect of the following factors was evaluated: Agrobacterium concentration (OD600=0.3, 0.5 and 1), during inoculation (5 seconds, 10 minutes and 30 minutes), co-culture (2 and 3 days), and the selection regime (phosphinothricin at 1, 3, 5 and 10 mg/l and kanamycin at 25, 50, 75 and 100 mg/l). In following, transformation efficiency and the chimeric transgenic shoots rate were respectively confirmed by PCR and GUS assays. The results showed that Agrobacterium strain LBA4404, at the OD600 of 0.5, with 5 seconds (for epicotyl) and 10 minutes (for internode) inoculation at two-day co-culture period, were identified the most suitable treatments for both explants. The transformation frequencies ranged from 0.93% for internode on DKW medium containing 1.0 mg/l of phosphinothricin to 14.29% for epicotyl on DKW medium containing 50 mg/l of kanamycin. Inclusion of the high-level of selective treatments, improved the transformation rate through decreasing frequency escape and chimeric transgenic shoots. These findings provide novel insights into the appropriate procedure to constitute non-chimeric lime transgenic shoots.
Molecular Genetics and Genetic Engineering
Ali Saeedpour; Soodabeh Jahanbakhsh; Tahmineh Lohrasebi; Kasra Esfahani; Ali Hatef Salmanian; Khadijeh Razavi
Abstract
Conventional pBI121-based binary vectors are widely used in transformation of higher plants mediated by Agrobacterium but they are useless in transformation of some monocots because of inefficiency of kanamycin in selection, while, hygromycin resistance gene is an important selectable marker that usually ...
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Conventional pBI121-based binary vectors are widely used in transformation of higher plants mediated by Agrobacterium but they are useless in transformation of some monocots because of inefficiency of kanamycin in selection, while, hygromycin resistance gene is an important selectable marker that usually used in transformation of several plants, especially monocots. The aim of this study was to improve the pBI121 vector for transformation of monocot plants. For this purpose, the hygromycin resistance gene with the 35S terminator were isolated from p6-ubi-rnai plasmid and cloned into pBlueScript intermediate vector via SmaІ and NotI restriction enzyme digestion. The CaMV 35 promoter was isolated from pBI121 vector by using SmaI and HindIII enzymes and cloned upstream of the gene. By using HindIII and Eco53KI enzymes, the complete hygromycin resistance gene cassette was replaced the kanamycin resistance gene cassette (which digested by HindIII and MssI) of pBI121 vector. Construction of this vector was confirmed by PCR method, digestion pattern analysis, and sequencing. Due to the popularity of pBI121-based vectors than other binary vectors and the researchers' familiarity with their manipulation, the vector which is introduced in this study could be used in gene transfer studies of monocot plants.
