Crown gall caused by Agrobacterium spp. has been observed in various crop species and in several provinces of Iran in recent years. In an attempt to identify the Agrobacterium species causing the disease in different areas of the country, strains were isolated from various infected crop species and characterized by phenotypic features, electrophoretic profile of cell proteins and BOX IR fingerprinting.On the basis of their phenotypic features, the strains were differentiated into three separate groups. The phenotypic characteristics of the first group of strains were closely similar to those of A. tumefaciens (Rhizobium tumefaciens). Members of the second group, isolated from infected grapevines were also identified as A. tumefaciens. Strains of the third group were phenotypically different from all described species, but appeared to be more similar to A. tumefaciens. These strains were not able to grow on any of the selective media tested and displayed a limited host range, infecting mainly sweet cherry All strains had a similar plasmid profile. The electrophoretic profile of cell proteins of the strains was different, although some similarity of the pattern was noted in the high-molecular weight region. In fingerprinting using BOX IR primer, a high level of heterogeneity was observed, nonetheless two major groups were differentiated. Phenotypic features appeared to be reliable criteria in identification of Agrobacterium species encountered in this study.

During the years 1997-1998, thirty-one Agrobacterium isolates were obtained from gall and sap of infected grapes as well as from soil in vineyards of Fars and Kohkilouyeh and Boyerahmad province. Two pathogenic and one non- pathogenic isolates of Agrobacterium tumefaciens Biovar1 were selected and their cell protein patterns compared through gel electrophoresis. A pathogenic and one non- pathogenic isolate of A. vitis and A. tumefaciens Biovar1 were selected from which antisera were prepared. Serological studies based on agar gel diffusion placed bacterial isolates in 4 serogroups while slid agglutination test placed the isolates in 6 sergroups. A comparison of cell proteins pattern showed that A. vitis and A. tumefaciens Biovar1 isolates were heterogenous, even though similar protein bands existed among the isolates.

Atropa belladonnais one of the most important medicinal plants in Solanaceae family.It contains tropani alkaloids that often are synthesised in root. Present study was conducted in order to induction of hairy root in A.belladonna using gene transfer via Agrobacterium rhizogenesmethod. The stem explants with Agrobacterium suspensions harbouring rolB gene were inoculated. Then, in order to direct regeneration, five compounds (MS, MS+3 mg/l Kin , B5, MS+12 mg/l Kin, B5+5 mg/l Kin)) in a completely randomized design with three replications was used. The statistical analysis indicated that among treated hormone, 12 mg /l KIN level in MS medium showed the most shoots direct regeneration. Two methods for the analysis of transgenic plants, phenotypic (observed in hair roots of transgenic seedlings), gene amplification of the rolB (using PCR) was used.

Agrobacterium tumefaciens mediated transformation may offer a better alternative than the biolistic gun for genetic transformation of maize plants. This gene delivery system results in a greater proportion of stable, low-copy number transgenic events than does the biolistic gun, and is highly efficient. In the present work, we studied maize transformation using A. tumefaciens by identifying some important factors that affect transformation efficiency subsequent tissue culture and regeneration of transgenic plants. Although, all genotypes produced embryogenic calli, S61 and A188 lines had higher percent (75% and 71% respectively) of regeneration than the other ones. Transformant events obtained when immature embryos (1.5-2 mm) were inoculated with A. tumefaciens LBA4404 harboring a standard binary vector pCAMBIA3301 after 72 h pretreatment culture of the embryos. Polymerase chain reaction (PCR) confirmed the presence of the gus and bar genes in the genome of regenerated plants. The transformation frequency (the number of independent, PCR-positive transgenic plants per 100 embryos infected) was 6.45% for S61 genotype. Therefore, our results identified suitable genotype (S61), embryo size (1.5-2 mm), A. tumefaciens strain (LBA4404), pretreatment culture, and appropriate antibiotic (Timentin) for Agrobacterium mediated transformation of Z. mays.

Crown gall is one of the most destructive bacterial diseases of plants. Nowadays, special attention has been focused on the biological control of plant diseases as an alternative to chemical control. This study was conducted to better understanding the molecular mechanism of Surfactin on Agrobacterium tumefaciens as a prerequisite for the use of Bacillus as a biocontrol agent of this pathogen. In this study, Tobacco plants (Nicotiana tabacum), IBRC-M10701 strains of A. tumefaciens, and pure commercial Surfactin (25 μ m) were used. miRNAs and lox genes have an important effect in the auxin signalling pathway. Using Real-time PCR, the expression level of miR167 and lox gene measured 1, 3, and 6 days after inoculations in the interaction of A. tumifaciens IBRC-M10701 and Surfactin. The expression level of lox gene in Agrobacterium treatment showed 0. 47, 22. 9, and 61. 8 increased. In Surfactin treatment it was 4. 6, 3. 6 and, 11. 6 fold and in Surfactin-Agrobacterium treatment this amount was 4. 2, 38. 8, and 20. 3 fold. In addition, the expression level of nta-miRNA167 in Agrobacterium treatment indicated an increase of 3. 4 and 214. 4 fold (in the first and third day after inoculation), then decreased to 2. 5 fold (in the sixth day), in treatment with Surfactin the amount of expression level was detected as 3. 2, 13. 2 and 4. 5 fold and in Surfactin-Agrobacterium treatment this amount was 1. 6, 2. 2 and 9. 6 fold compared with the control. All of the results indicated the positive effect of Surfactin in suppression the strain IBRC-M10701 of Agrobacterium. The results indicated the key role of Surfactin in biocontrol which reflected the possible use of Bacillus strains producing Surfactin in biological control.