Content area
Abstract
Genetic engineering has been used as an alternative method to classical breeding procedures to enhance plant resistance to pests and pathogens. Various non-plant antibacterial protein genes have been introduced into plants, providing resistance against bacterial pathogens. Among the non-plant antibacterial protein genes human lactoferrin (HLF) appears to be the most promising to use because of several unique properties.
A tomato line (Lycopersicon esculentum Mill.) susceptible to bacterial wilt was transformed with Agrobacterium tumefaciens (At) strain C58C1 containing a binary vector carrying a modified HLF cDNA. The introgression of HLF cDNA and the expression of full-length HLF transcript and protein were detected by Southern, Northern, and Western blot analyses, respectively. A stable Mendelian segregation for a single gene was observed in the T1 and T2 generations based on resistance to kanamycin. All T1 and T2 plants resistant to kanamycin showed the single corresponding band of HLF cDNA in Southern blot analysis. Two transgenic lines LF-T1-29 and LF-T1-34 exhibited early resistance in comparison to the control and subsequently susceptibility to bacterial wilt.
There are no reports on the successful transformation of common bean (Phaseolus vulgaris L.) using the At-mediated transformation method. In this study, various factors affecting the At-mediated transformation efficiency of common bean were optimized, based on transient GUS (β-glucuronidase) gene expression. An antioxidant treatment using 3.3mM cysteine and 1.1mM ascorbic acid significantly increased the infection rate and GUS gene expression on the differentiating tissues of cotyledonary node explants of common bean. By combining the optimized parameters, 16% of total explants, showed GUS expression on the differentiating tissues of regenerated explants, thus providing useful information to pursue further research on common bean transformation.
