Search Results (4)

Agrobacterium (Rhizobium)-mediated transformation leads to the formation of crown galls or hairy roots on infected plants. These effects develop due to the activity of T-DNA genes, gathered on a big plasmid, acquired from agrobacteria during horizontal gene transfer. However, a lot of plant species are known to contain such sequences, called cellular T-DNAs (cT-DNAs), and maintain normal phenotypes. Some of the genes remain intact, which leads to the conclusion of their functional role in plants. In this study, we present a comprehensive analysis of the cT-DNAs in the Nicotiana noctiflora Hook. genome, including gene expression and opine identification. Deep sequencing of the Nicotiana noctiflora genome revealed the presence of two different cT-DNAs, NnT-DNA1 and NnT-DNA2, which contain the intact genes iaaM, iaaH, acs, orf13, orf13a, and orf14. According to the expression analysis results, all these genes are most active in roots in comparison with other organs, which is consistent with data on cT-DNA gene expression in other plant species. We also used genetic engineering approaches and HPTLC and HPLC-MS methods to investigate the product of the acs gene (agrocinopine synthase), which turned out to be similar to agrocinopine A. Overall, this study expands our knowledge of cT-DNAs in plants and brings us closer to understanding their possible functions. Further research of cT-DNAs in different species and their functional implications could contribute to advancements in plant genetics and potentially unveil novel traits with practical applications in agriculture and other fields. Full article

The biocontrol of crown gall has been practised in Australia for 48 years. Control is so efficient that it is difficult to find a galled stone fruit tree, when previously, crown gall had been a major problem. This paper explains how it works and why only pathogens are inhibited. A commercial biopesticide is available in Australia, Canada, Chile, New Zealand, Turkey, the USA, South Africa and Japan. The challenges of commercialising a biopesticide are outlined. Rigid regulations are preventing the wider use of biocontrol organisms. Full article

Phosphodiesters of glucose-2-phosphate (G2P) are found only in few natural compounds such as agrocinopine D and agrocin 84. Agrocinopine D is a G2P phosphodiester produced by plants infected by Agrobacterium fabrum C58 and recognized by the bacterial periplasmic binding protein AccA for being transported into the bacteria before cleavage by the phosphodiesterase AccF, releasing G2P, which promotes virulence by binding the repressor protein AccR. The G2P amide agrocin 84 is a natural antibiotic produced by the non-pathogenic Agrobacterium radiobacter K84 strain used as a biocontrol agent by competing with Agrobacterium fabrum C58. G2P esters are also found in irregular glycogen structures. The rare glucopyranosyl-2-phophoryl moiety found in agrocin 84 is the key structural signature enabling its action as a natural antibiotic. Likewise, G2P and G2P esters can also dupe the Agrobacterium agrocinopine catabolism cascade. Such observations illustrate the importance of G2P esters on which we have recently focused our interest. After a brief review of the reported phosphorylation coupling methods and the choice of carbohydrate building blocks used in G2P chemistry, a flexible access to glucose-2-phosphate esters using the phosphoramidite route is proposed. Full article

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease in various hosts across kingdoms. In the present study, five regions (Wonju, Jincheon, Taean, Suncheon, and Kimhae) of South Korea were chosen to isolate A. tumefaciens strains on roses and assess their opine metabolism (agrocinopine, nopaline, and octopine) genes based on PCR amplification. These isolated strains were confirmed as Agrobacterium using morphological, biochemical, and 16S rDNA analyses; and pathogenicity tests, including the growth characteristics of the white colony appearance on ammonium sulfate glucose minimal media, enzyme activities, 16S rDNA sequence alignment, and pathogenicity on tomato (Solanum lycopersicum). Carbon utilization, biofilm formation, tumorigenicity, and motility assays were performed to demarcate opine metabolism genes. Of 87 isolates, 18 pathogenic isolates were affirmative for having opine plasmid genes. Most of these isolates showed the presence of an agrocinopine type of carbon utilization. Two isolates showed nopaline types. However, none of these isolates showed octopine metabolic genes. The objectives of the present study were to isolate and confirm virulent strains from rose crown galls grown in the different regions of Korea and characterize their physiology and opine types. This is the first report to describe the absence of the octopine type inciting the crown gall disease of rose in South Korea. Full article