Arabidopsis thaliana is a favorite model plant for biotechnology studies by which a remarkable development happened in plant sciences including plant breeding during the last decade. Inducing useful mutants, resistant to various environmental stresses, their recognition and transferring to other plant species, lacking the resistance, is one of the major applications of the species. Resistance to herbicides is one of the characteristics, which is very attractive to the breeders. This research was carried out to investigate the inheritance mode of the factors controlling resistance to uniconazol (a GA-biosynthesis inhibitor). Forty-eight variable gene pools created through inserting T-DNA to the genome of the Colombia ecotype of the species were received from Prof. Cutler from Toronto University, Canada, and used in this research to identify the uniconazol resistance genotypes. Twelve concentrations of the herbicide were tested on the Colombia ecotype to find the critical dilution ofuniconazol on which no wild type seed can germinate and grow. The gene pools were screened on the critical dilution and a number of the resistant seedlings were recognized. To investigate their gene function and the number of genes controlling the character, one of the mutants was crossed to the wild type Colombia and Landsberg ecotypes. F1 and F2 generations were also generated. Testing the parents and the two F1 and F2 generations on the critical dilution of the chemical, revealed that one dominant gene is controlling the character in the mutant.

Thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) in which asymmetric annealing temperature is used was employed to discriminate sequences flanking T-DNA insertions in Arabidopsis thaliana. In this method, left and right border sequences of the T-DNA insertions were regarded as the two tagged positions and two series of primers differing in length and annealing temperature were used to amplify the target sequences. The technique uses a series of nested primers specific to the known sequence of the left and right borders of the T-DNA and a series of shorter arbitrary primers with lower annealing temperature. Four mutants of Arabidopsis thaliana resistant to uniconazol (a GA-biosynthesis inhibitor), due to T-DNA insertions in their genome were studied in this research. TAIL-PCR was performed in three stages which in the second and third stages, diluted PCR products of the first and second stages were used respectively as the DNA template. In each stage of the TAIL-PCR a combination of five arbitrary primers and two specific primers for left and right borders of the T-DNA were used to amplify the target sequences in the four different mutant DNA samples. In other words, forty different reaction conditions were prepared and performed simultaneously. Investigating the PCR products of the second and third stages on 2% agarose gel and comparing the mutants bands related to the two stages, specific PCR products were detected and separated from non-specific products. Selecting the suitable bands with appropriate size, Qiagene kit was used to purify the PCR products and sequenced. Conforming the obtained sequences to the T-DNA left and right borders, indicated that the method amplified the targeted sequences with a high accuracy.

Condensed tannins (CTS) are flavonoid oligomers, many of which have beneficial effects on animal (safe bloat) and human health. The functions of CT are due to their ability to form reversible complex with proteins, the formation of these protein-tannin complexes making protein unavailable for microbial enzyme and activate other mechanisms like deprivation of metal ions and inhibition of oxidative phosphorylation which also results in the prevention of foam formation and bloating. Anthocyanins are flavonoids that contribute to the red, violet or blue pigmentation of both seeds and flowers. The BAN gene encodes anthocyanidin reductase (ANR), an enzyme proposed to convert anthocyanidins to their corresponding 2, 3-cis -flavan - 3-ols ((+)-catechin). Transformation of leaf explants from Medicago sativa var. Rgsy27 and M.sativa var. PI genotypes was carried out with the plasmid pBI121.BAN (binary vector containing the BAN gene) by two strains of Agrobacterium tumefadens (LBA 4404 & ERA 105). Leaf explants of Rgsy27 produced more than 90% proembryogenic calli, but in PI produced about 30%. More than 65% of regenerated embryos were changed to whole plants in both genotypes. The efficiency of transformation in Rgsy27 and PI plants was depended on Agrobacterium strains, so that the strain LBA 4404 was efficient more than ERA 105 for transformation of both genotypes. Ectopic expression of the BAN in Alfalfa transgenic foliage resulted in accumulation of CTs. Thus, it has been assumed that the BAN gene also acts as starter units in tannins condensation in alfalfa. Loss of the BAN gene function increases the amount of red pigment, suggesting that the BANYULS protein might be a negative regulator of pigment production.BANYULS activity is limiting factor for CT production, making this enzyme an attractive target for induction of over expression in forage plants, such as alfalfa (Medicago sativa) with the goal of inducing CT production in their foliage. The condensed tannin percentage in dry matter of transgenic Rgsy27 and PI plants was 0.474 and 0.600, respectively and 0.259 and 0.408 in control plants.

Gene expression patterns at early stages of somatic embryogenesis in chick pea was studied using 2,4-D and 2,4,5-T (3 mg/L each) in MS medium. Emberyogenic callus was produced in media containing 2,4,5-T followed by forming globular shape embryos while this did not occur in the media containing 2,4-D. In order to study the effect of these treatments on the embryogenesis patterns, differential display (RAP-PCR) was used. Extraction of mRNA from callus tissue was carried out 7, 14, 21, 28, 35 and 42 days after zygotic embryo culture. Reverse transcript reaction of cDNA first strand was made using three oligo dt primers anchored with; dTA, dTG, dTC and amplification step was performed by the use of 8 arbitrary primers of 12 nucleotides. Separation of bands was done on the denaturing polyacrilamide gel and vertical electrophoresis. The bands were shown by using silver nitrate (AgN03) staining method and resulted bands were pictured by scanner and saved in computer memory. The number of dT bands was used as an indicator of gene expression. The results showed that dTC oligo primer produced maximum number of bands. All primers showed the same gene expression pattern. The gene expression was high at first and the second weeks of culture, but from the third to fourth weeks the rate of gene expression ceased while a considerable increase in gene expression was observed in the fourth to sixth weeks of culture. Although there was differences between the treatments all during the stages of the experiment, but the difference was more obvious at late stages of embryogenesis. The results showed the same gene expression pattern in chick pea was however different in terms of comparing with the studied model plants, but it was similar from the point of view of its pattern.

Different gene transfer strategies, based on tissue culture, are employed in plants such as rapeseed. These strategies suffer from constraints like; need of transgenic cell regeneration, somaclonal variation, in ad9ition to being costly and time consuming. Considering the constraints, researchers often resort to planta transformation. This strategy, in addition to simplicity, low cost, and avoidance of somaclonal variation is of the feasibility for species for which tissue culture application hasn't been developed. Vacuum infiltration was primarily applied in Arabidopsis thaliana L. It has been used in several other species like radish. This investigation explains gene transfer into rapeseed using vacuum infiltration, for the first time in Iran. An arabidopsis inbred line was used as a check, and the frequencies of transgenic plants were compared. Two Agrobacterium strains, EHA101 and C58(pGV3101) containing pVW295 plasmid having NPTII and GDS genes were used in the investigation. The flowering rapeseed and arabidopsis plants were inverted into the agrobacterium culture in a vacuum chamber applying -350 to -400 mmHg of pressure for 30-40 seconds. Seeds from infiltrated rapeseed and arabidopsis plants were selected in media containing 50 and 30 mgL-1 Kanamycin respectively. To confirm the GUS gene transfer into the selected progenies histochemical evaluation was conducted. The histochemical assay confirmed the GDS gene transfer. Evaluation of the infiltrated plant seeds revealed that the frequency of transgenic arabidosis was more than that in rapeseed. Agrobacterium strain EHA101 was more efficient than C58 (pGV3101) in gene transfer into either of arabidosisor rapeseed.

The objective of this research is to identify Arabidopsis thaliana genes encoding acid phosphatases induced by phosphate starvation. Multiple alignments of eukaryotic acid phosphatase amino acid sequences led to the classification of these proteins into four groups including purple acid phosphatases (PAPs).Specific primers were degenerated and designed based on conserved sequences of PAPs isolated from plants, fungi and animals. RNA profiles of Pi-fed and Pi-starved A. thaliana roots were compared with two methods established for gene-family-directed differential display of pap genes. Having analyzed the differentially displayed fragments, seven pap encoding cDNA clones were isolated. One of the clones was a transsplicing product of two genes that encodes an acid phosphatase carrying a zinc-finger domain. Six other clones were predicted to encode secretory phosphatases. Reverse-northern blotting and semi-quantitative RT-PCR revealed distinct expression patterns for each gene under diverse environmental conditions such as Pi starvation, high-salt concentration, cold shock, nitrogen and sulfur deprivation. The presented data can provide some clues for dissecting the possible roles of PAPs in Pi acquisition.

Some plants are naturally able to acquire nitrogen from the air through a process called symbiotic nitrogen fixation. In soybean, a close interaction between the root and Bradyrhizobium japonicum results in the formation of nitrogen-fixing nodules. Both partners benefit from this interaction: the bacterium gains sugar from the plant, and the plant gains reduced nitrogen. Regulation of this symbiosis is necessary for optimal plant development. Auto regulation of Nodulation (AON) is the main genetically-controlled mechanism that regulates nodulation. To identify genes that function in either the shoot or root to regulate AON we have utilized transcriptional profiling and quantitative real-time reverse transcriptase (QRT) PCR to analyze gene expression in wild type and the GmNARKAON mutant. QRT-PCR experiments confirmed the expression of two genes (GmaAffx.32318.1 and Gm.5873) that were predicted by Affymetrix microarray analyses to be decreased in wild type related to mutant and regulated in the leaf by GmNARK in a rhizobia-independent manner. One of these genes (GmaAffx.32318.1) that were sequenced is predicted to encode a Ca-transporter, with 80% similarity to a heterologous gene in rice. QRT-PC Ranalyses for another 4 candidate genes didn't show any significant differences between wild type and GmNARK mutant plants, as suggested by the microarray analyses. Microarray and QRTPCR analyses of gene expression in specific root zones of wild type and GmNARK mutant plants suggests that a HMG-CoA reductase I may function in the root to regulate nodule number. This gene was cloned by BAC library Screening and its predicted protein has 85% similarity to HMGRl of Arabidopsis. The discovery of new components in the AON circuit enriches our ability to investigate systemic control of plant development and its integrative in kages to other signaling networks.