Phaseolus vulgaris L. is the most important economic species within the genus Phaseolus. It is grown in all parts of the world. Genetic improvement by conventional breeding has met considerable success, although production of hybrids between species within the genus has been limited due to sexual incompatibility. Recent advanc...es in tissue culture have offered the opportunity to produce cultivars, which could not be obtained by conventional breeding methods. The use of tissue culture and genetic engineering is viewed as a logical approach to improve bean production. Gene transfer techniques will have a great impact on legumes. Although the concept of cell totipotency is widely proved, in vitro morphogenesis has not yet been achieved for a large number of cultivated beans. Regeneration protocols are strongly influenced by the genotype. In tissue and cell culture of beans, the factors controlling shoot morphogenesis and somatic embryogenesis are still unknown. The reported data suggest a possible way for future research.
Callus cultures were induced from hypocotyl of young bean seedlings. Callus developed and maintenaned on B5 medium supplemented with 2mg/1 2,4-D and 1 mg/1 kinetin. The results demonstrate that A. tumefacins-mediated transformation is a convenient method to obtain transient gene expression in callus of bean. The results have shown that... the bean callus co-cultivated with A. tumefaciens can be transformed to get heibicide Finale (glufosinate-ammonium) resistant GUS positive tissues. Southern blot analysis of transformed calli showed integration of gusA marker gene carried by a binary vector. Transformed calli were selected on herbicide containing media. Data of molecular analysis (Southern blotting) confirmed the insertion of gusA gene in the genome of herbicide resistant calli with bar gene. There are three evidences that calli are stable transformants: (1) herbicide resistance, (2) GUS activity which is indicative since the coding region containing an intron, (3) the results of Southern hybridization technique.
Callus cultures were induced from hypocotyl of young bean seedlings. The B5 medium completed with 1 mg/1 KIN and 2mg/1 2,4-D proved the best. Callus developed and maintenaned on B5 medium supplemented with 1mg/1 kinetin and 2mg/I 2,4-D. The B5 medium supplemented with 1mg/1 KIN and 2mg/1 2,4-D induced much more callus than half strength MS medi...um supplemented with 0.5 or 0.75mg/1 BA and 0.1 mg/1 NAA. The results demonstrate that GeneboosterTM is convenient method to obtain transient gene expression in callus of bean. The results have shown that the bean callus shot by GeneboosterTM can be transformed to get (kanamycin-resistant and stress mannitoltolerant) calli. The presence of mannitol-dehydrogenase gene (mt/) was verified by PCR, showing the integration of mt/ gene carried by two plasmids. Co-transformed calli were selected after bombardment on kanamycin, mannitol and (kanamycin+mannitop-containing media. Data of molecular analysis (PCR) confirmed the insertion of mtl gene in the genome of mannitol-tolerant callus lines.
We have found that 50 mg/I kanamycin and 0.8 Mo1/1 mannitol concentration was sufficient to kill the control callus of bean (Phaseolus vulgaris L.) and differentiate transgenic from the non-transgenic cells. The GeneBooster particle delivery system was used for the bombardment of bean callus. The kanamycin resistance g...ene was used as a selectable marker. The test was made by transferring the healthy white callus, subcultured for three months on selective and non-selective medium. After selection on kanamycin containing media, several kanamycin resistant calli had been obtained, survived and grew. After selection on mannitol containing media no drought resistant calli had been obtained. Resistance of the selected calli were verified by their ability to grow repeatedly on selective medium containing 150 mg/I kanamycin. Selective pressure was maintained over a period of 8 months.
We report the method for the establishment of rapidly growing callus cultures of Phaseolus vulgaris and the conditions required for efficient transformation using high velocity microprojectiles and high level of transient gene expression. Using hypocotyl explant and vertical culture on B5 medium with lmg/1 kinetin and 2 mg/1 2,4-D, we can recom...mend to get a rapidly growing callus from bean which is a good starting material to introduce foreign DNA into bean cells. The GeneBooster particle delivery system was used for the bombardment of bean callus and the Hgm resistance gene (Hgmr) was used as a selectable marker gene. 25mg/I hygromycin (Hgm) concentration was sufficient to kill the control callus. We used the standard physical factors, the appropriate pressure of N2 gas for the bombardment of the callus tissue, the shooting distance and the size of tungsten particles used as microprojectiles. Selective and nonselective tests were made by transferring the healthy green and white calluses, subcultured for 4 months on selective and nonselective medium. Several Hgm resistant calli had been obtained. Selective pressure was maintained over a period of 10 months.
In this paper we report the establishment methods of a rapidly growing callus culture of Phaseolus vulgaris bean as well as the conditions required for a high level of transient gene expression using Agrobacterium-mediated transformation. A vector is containing both the lindan-resistance gene as a selectable marker, and GUS ge...ne as a screenable marker. By using hypocotyl explant and vertical culture on B5 medium supplemented with 1 mg/1 kinetin- and 2,4-D 2 mg/1 and subcultured every 3-4 weeks, we can recommend to get a good and much callus from bean. This will help in introducing foreign DNA into callus cells. One strain of Agrobacterium carrying plasmid as vector for introducing foreign DNA into plant cells was used. At different concentrations of lindan; 3, 4 and 4.5 mg/I, the transformed Maxidor callus survived and grew over a period of 6 month and subcultured every 3-4 weeks, but the control callus died. Callus were assayed for GUS activity to confirm the expression of the GUS gene using the histochemical assay test. The GUS gene was also correctly expressed in callus cultures grown on 4mg/I lindan-selected medium, the typical blue colour in the histochemical assay using the X-gluc as substrate. But the control, non-transformed callus was not able to grow in the presence of lindan, neither showed a positive reaction in the in vitro assays.
Dry seeds from two cultivars of common bean (Phaseolus vulgaris L.) were germinated on sterile cotton and sterile deionized distilled water. Cotyledonary node tissue of seedlings were cultured on Murashige and Skoog(MS)-based media supplemented with different combination of N6-benzyl-aminopurine (BAP) and indole-3-acetic aci...d (IAA), and benzyladenine (BA) and a-naphthaleneacetic acid (NAA). The results revealed that the regeneration percent and the average number of buds and shoots per explant were influenced by the type of explants and exogeneously added hormones. Multiple shoot induction on dry bean cotyledonary node that contain 4-5 mm from cotyledons and hypocotyl on a medium containing full concentration of MS inorganic salts supplemented with 0.5mg/1 BA and 0.1mg/1 NAA was feasible and the method can be applied in transformation experiments.