Plant Disease and Biotechnology
Neda Khoshkhati; Omid Eini; Davoud KOOLIVAND
Abstract
Tomato bushy stunt virus (TBSV), a member of the genus Tombusvirus is one of the causal agents for curly disease in tomato plants. In this study, the interaction between a mycorrhizal fungus, Rhizoglomus irregular, and TBSV in tomato plants was investigated. In a completely randomized design experiment, ...
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Tomato bushy stunt virus (TBSV), a member of the genus Tombusvirus is one of the causal agents for curly disease in tomato plants. In this study, the interaction between a mycorrhizal fungus, Rhizoglomus irregular, and TBSV in tomato plants was investigated. In a completely randomized design experiment, tomato seedlings were inoculated with R. irregular and after four weeks they were inoculated with TBSV. Four treatments were included: control plants (C), TBSV -infected plants (V), mycorrhizal plants (M), TBSV -infected mycorrhizal plants (MV). Nineteen days after inoculation the infected plants were tested for symptom production and virus accumulation. Results of symptoms evaluation based on the disease severity index showed a lower disease severity in MV plants compared with V plants. Supporting this result, a lower level of virus accumulation was observed in V plants which was more significant at long-term infection. The expression of methylation-related genes including ADK, HEN1 and MET1 was tested by Real-time PCR. Results showed that the expression of these genes was significantly higher in MV plants as compared with V plants. An increase in the expression of methylation-related genes in MV plants indicates that resistance to the virus is likely to occur through methylation and also supports the lower level of virus accumulation in MV plants.
Microbial Biotechnology
Roghayeh Zare; Mehrooz Dezfulian; Zahra Amini; Ebrahim Karimi; Akram Sadeghi; Razieh Rahmati
Abstract
The use of the synergistic effect of nitrogen-fixing bacteria and phosphate solubilizing bacteria is one of the newest biofertilizer production strategies. Rhizosphere soil samples were collected from tomato, cucumber and bell pepper commercial greenhouses and screened for Pseudomonas and Bacillus using ...
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The use of the synergistic effect of nitrogen-fixing bacteria and phosphate solubilizing bacteria is one of the newest biofertilizer production strategies. Rhizosphere soil samples were collected from tomato, cucumber and bell pepper commercial greenhouses and screened for Pseudomonas and Bacillus using selective media. One hundred and eight Pseudomonas and 92 Bacillus isolates with PGP activities were isolated and characterized. Fifty-three percent of Pseudomonas isolates and 25% of Bacillus were able to grow on N free medium. Ninety-six percent of Pseudomonas isolates were able to solubilize organic phosphate and 70% of them produce IAA, while none of the Bacillus had these two abilities. About 30% of Pseudomonas and Bacillus isolates produces siderophore, although the ratio of orange halo diameter/colony diameter was greater for Pseudomonas. Only five Bacillus and 31 Pseudomonas isolates inhibited the growth of Phytophthora melonis. Based on these results, although PGP isolates of both genera were found in the rhizosphere soil of commercial greenhouses, these bacteria differed in PGP traits. A Pseudomonas isolate, P3-57 and a Bacillus isolate, C1BY-1 with 50% antagonistic activity against P. melonis which differed in PGP traits selected for future study in greenhouse conditions. Phylogenetic analyses of 16S rRNA gene sequence revealed that strains P3-57 and C1BY-1 are closely related to P. putida and B. subtilis respectively.
Biotic and Abiotic stress
Parviz Heidari
Volume 6, Issue 14 , August 2016, , Pages 17-25
Abstract
Auxin is a central hormone that exerts pleiotropic effects on plant growth including the development of shoots, roots, and other organs under normal condition or stress. In this study, the transcripts change of AUX/IAA, ARF, BRX and PIN4 which involve in auxin transporter and signaling were evaluated ...
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Auxin is a central hormone that exerts pleiotropic effects on plant growth including the development of shoots, roots, and other organs under normal condition or stress. In this study, the transcripts change of AUX/IAA, ARF, BRX and PIN4 which involve in auxin transporter and signaling were evaluated in root of tolerant and sensitive tomato genotypes under 15°C. AUX/IAA4 which is a negative regulator of auxin response genes was strongly up regulated in tolerant genotype at 15°C however, the transcript level of this gene was decreased in sensitive genotype. ARF and PIN4 were highly up regulated by suboptimal temperature in sensitive genotype whereas they were down regulated in tolerant genotype in recovery time (2 hours). The expression pattern of BREVIS RADIX (BRX) gene as a common point of interaction of auxin and brassinosteroids suggested that the BRX gene under sub optimal temperature in sensitive genotype was up regulated and reached the maximum level after 2h transfer to 23°C. The results of this study show that auxin concentration is increased in sensitive genotype and it induced the ARF, PIN4 and BRX whereas AUX/IAA4 was repressed. The results of common motifs in 1500 bp of upstream revealed that the AATAT motif of PRISM algorithm was frequency observed in all genes.
Tissue culture and Micropropagation
Behzad Ahmadi; Rasoul Asghari Zakaria; Mehran Enayati Shariat Panahi; Naser Zare; Pejman Azadi
Volume 5, Issue 10 , September 2015, , Pages 17-29
Abstract
In this study, the effect of cold treatment (4 °C for 1 to 5 days) in combination with heat shock (30 °C for 1 to 10 days) and also colchicine treatment (25 to 100 mg/l for 24 to 72 h) were assessed on induction of sporophytical divisions in isolated microspore culture in two hybrid tomato cultivars ...
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In this study, the effect of cold treatment (4 °C for 1 to 5 days) in combination with heat shock (30 °C for 1 to 10 days) and also colchicine treatment (25 to 100 mg/l for 24 to 72 h) were assessed on induction of sporophytical divisions in isolated microspore culture in two hybrid tomato cultivars (‘Berlina’ and ‘Petoperide’). Microspore-derived structures with more than 10 nuclei were only observed in cv. ‘Berlina’ and in the cultures incubated for 1 or 2 days at 4 °C and then for 2 days at 30 °C. In addition, cold treatment for 1 or 2 days and then 2 days at 30 °C could efficiently induce formation of microspore-derived structures with 9-10 nuclei in both cultivars tested. No microspore with more than 5 nuclei was observed in the cultures treated at 30°C for 10 days. In the cv. ‘Berlina’, microspore-derived structures with 9-10 nuclei were detected when 25 mg/l colchicine was used for 48 h, while in cv. ‘Petoperide’, microspore-derived structures with more than 8 nuclei were not observed in all treatments tested. Globular embryos were only produced in two-layered culture medium when treated at 4°C for 2 and 5 days and then subjected to 30°C for 2 days. Microspore embryogenesis could be induced in tomato if appropriate duration of cold and heat treatment was selected.
Genetic Engineering and Gene Transformation
Nahid Ahmadi; Hasan Rahnama
Volume 3, Issue 4 , September 2013, , Pages 77-85
Abstract
Transient expression of foreign genes in plant tissues is a valuable tool for plant biotechnology and to shorten the time for gene functional analysis. Transient expression is a fast, flexible, simple and easy method that could be used in fully differentiated plant tissues. 2A11 promoter is a tomato ...
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Transient expression of foreign genes in plant tissues is a valuable tool for plant biotechnology and to shorten the time for gene functional analysis. Transient expression is a fast, flexible, simple and easy method that could be used in fully differentiated plant tissues. 2A11 promoter is a tomato fruit specific promoter whose expression occurs in fruit significantly. Cloning of fruit-specific promoter (2A11) is the main purpose of this study. 2A11 promoters were amplified from genomic DNA of tomato by PCR using specific primers. The promoter fragments were cloned into cloning vector PTZ57R/T. Recombinant plasmids were transferred into E. coli XLI-blue strain. Fragments of the interest were digested using restriction enzymes BamH1 and HindIII and were then purified and substituted in CaMV35S promoter in binary pBI121. Binary pBI121 was selected for cloning of 2A11 promoters as it is an ideal vector for agroinfiltration due to the presence of the CaMV35S promoter and the GUS reporter gene within its T-DNA region. Recombinant plasmids were transformed into Agrobacterium tumefaciens LBA4404 strain with freeze and thawing method. The expression of GUS gene was analyzed in tomato with agroinfiltration method. The results showed that, 2A11 promoter was found as efficient as CaMV35S promoter in expression of GUS gene specifically in tomato fruit. Then, we can use this promoter for tissue specific expression of recombinant proteins in tomato fruits.
