مجله بیوتکنولوژی کشاورزی
پیاپی 1 (پاییز 1388)

Study of genes involved in flower formation could help to increase our understanding of floral organ identity mechanisms. In this research, the expression pattern of four MADS- box gene family including RaA2, RaB17, RaG24 and RaK17 isolated from the dioecious plant Rumex acetosa was studied. RNA extracted from different tissues (inflorescence, stem, leaf and root) of male and female plants, was used for Northern blot analysis. RaA2 and RaB17 genes are expressed in reproductive organs but RaG24 and Ra K17 genes were shown to be expressed in both vegetative and reproductive organs. Alignment of their deduced proteins with other known MADS box proteins showed that they are belongs to distinct subfamily groups. The proteins of RaA2 and RaB17 genes showed the highest similarity to MADS proteins from Malus domestica and CMB1 from Diantus caryophyllus, respectively. The proteins of RaG24 and Ra K17 genes have the highest similarity to TDR3 protein from Lycopersicon esculentum and MADS5 protein from Betula pendula and POTM1 protein from Solanum tuberosum which are expressed in both vegetative and reproductive phases. In Southern blot analysis, there is a difference in hybridisation pattern between male and female. The simple pattern of hybridisation indicated that there is a single copy and small gene family of each gene in the genome.

By using molecular farming, plants are used as a bio-reactor for producing low costrecombinant proteins. This technology had been successful in the production of primaryproducts in the commercial field. Other recombinant products are in final steps of production.In the last 10 years, up to 100 different recombinant proteins are produced in transgenicplants. Plants have many advantages in comparison with other expression systems, especially in economic, safety, operations and production aspects. However, there are some problems for using plants as a bio-reactor with the goal of recombinant proteins production that should be considered. Some of these problems are: the quality of final product, extraction and the processing of plant derived pharmaceutical macromolecules and bio-safety. In this study, we will review the global view of molecular farming and some successful cases in Iran. During 8 years of research in the field of molecular farming in Iran, especially in Tarbiat Modarres University, different kinds of recombinant proteins such as VHH single domain antibody in tobacco and canola and tPA protein in tobacco were expressed. The human gamma interferon in canola and tobacco and also the luciferase enzyme in tobacco, African violet and canola were produced. Also, useful projects are executed in the field of transplastomic plants in order to express the mentioned genes in the chloroplast. In transferring the human pro-insulin gene to chloroplast genome, this gene was bombarded onto tobacco leaf ex-plants using a particle delivery system. Leaf ex-plants produced adventitious shoots when cultured onshoot-inducing medium containing spectinomycin. The results of PCR confirmed that thepro-insulin gene was present in the chloroplast genome.

Some plants are naturally able to acquire nitrogen from the air through a process calledsymbiotic nitrogen fixation. In soybean, a close interaction between the root and Bradyrhizobium japonica, results in the formation of nitrogen-fixing nodules. Both partners benefit from this interaction: the bacterium gains sugar from the plant, and the plant obtains reduced nitrogen. Autoregulation of Nodulation (AON) through the expression of GmNARK in soybean leave is the main genetically-controlled mechanism that regulates nodulation. Autoregulation of nodulation (AON), is a long-distance signaling network which acts to limit the proliferation of nodules which operates to limit the proliferation of nodules Affymetrix microarray and quantitative real-time reverse-transcriptase (QRT) PCR in wild type and the GmNARK AON mutant confirmed that the expression of GmaAffx.32318.1 has been decreased in wild type related to mutant and regulated in the leaf by GmNARK in a rhizobia-independent manner. This gene (GmaAffx.32318.1) that was cloned and sequenced is predicted to encode a Ca-transporter.It has 2460 bp with the coding sequence, upstream and downstream of gene. The predicted protein included 202 amino acids and contains 5 transmembrane domains that can be act as cell receptor or carrier with 70% similarity to a heterologous gene in Arabidopsis.

Fusarium Head Blight is a critical wheat disease in Iran, particularly in the provinces of;Mazandaran, Golestan, Ardabil (Moghan) and Fars. The main casual agent of this disease is the fungus Fusarium graminearum. Primary evaluation of 3350 bread wheat accessions of National Plant Gene Bank of Iran to FHB, revealed that some of them were resistant. Twenty two resistant samples along with 1 resistant check and 1 susceptible check derived from primary selection were evaluated using RCBD with 3 replications surrounded by the spreader in Gharakhil Research Station, Sari in autumn 2002. Five severe casual isolates of Fusarium were used for the resistance evaluation. Five times of spray inoculation were applied on the samples just before sunset, in which the concentration of inocula was 3×104 macro conidia/ml. The main agronomic traits were evaluated. The plant pathogen interaction characters, disease index, disease incidence and Fusarium damaged kernels were evaluated three times 10, 14 and 18 days after inoculation.Disease intensity area under the disease progress curve (AUDPC) was also calculated. Theresults revealed that several samples were resistant to disease compared to resistant check. Cluster analysis showed that the resistant accessions were grouped in the same cluster with the resistant check, Sumai#3. For achievement of markers linked to resistance, ten SSR primer pairs were applied. The samples produced different band patterns; however the primers GWM234, GWM251 and GWM340 were informative. They may be able to discriminate resistant samples through optimizing lab conditions and further trials.

To identify the QTLs responsible for salinity tolerance in tolerant line (FL478), 2350 BC3F4lines derived from IR29×FL478 were used at IRRI during 2005-2007. Significant differences among back cross families were found for salinity tolerance scoring, sodium and potassium concentration and their ratio. The results showed that the low ratio for Na+/K+ in FL478 is mainly through lower amount of Na+ uptake rather than high amount of K+. Selective Genotyping with 500 extreme individuals indicated that the highest and lowest number of QTLs for Na+ and K+, respectively. The result of QTL mapping by SSRmarkers using 500 extremes individuals showed the highest and lowest number of QTLs for Na+ and K+ respectively. Composite interval mapping analysis revealed that in addition to chromosome 1, there are major QTLs on chromosomes 6, 8, 10 and 12 for salinity tolerance at seedling stage in rice. In the Saltol region, one QTL was found for Na+ concentration while for the other traits the QTLs were found in the upper part of Saltol region. Major QTLs responsible for salinity tolerance scoring were located on hromosomes 1, 3 and 6. For Na+ concentration and Na+/K+ ratio, chromosomes 1, 3, 6, 10 and 12 contained the major QTLs which mainly originated tolerant parent. The epistatic effects were not found for any of detected major QTLs. Based on the present results, breeding methods for QTLs pyramiding using marker-assisted selection could be very useful for the development of new varieties with a high level of salt tolerance by targeting several major QTLs for salt-tolerance using FL478.

Evaluating and detection of genetic disorders is very important in both human and animal communities.Blood samples were prepared from 162 cows from Sarabi cows’ research station in Sarab, East Azerbaijan province, Iran. DNA extraction was done based on guanidine thiocyanate – silica gel method. The aim of this study was to identify the CVM and DUMPS carriers in Sarabi native cows of Iran. Standard polymerase chain reaction was applied to amplify a 177 bp and a 108 bp fragments from exon 4 in SLAC35A3 gene and exon 5 in UMPs gene using specific primers pair. The SLC35A3 gene PCR products were analyzed using single stranded conformation polymorphism (SSCP) to reveal their mutations on polyacrylamide gel. In order to identify DUMPS carrier animals, a RFLP assay was conducted and the UMPs PCR products were digested by AvaI restriction enzyme. Results indicated that no G→T mutation at position 559 in exon 4 of SLAC35A3 gene and C→T mutation at position 405 in exon 5 of UMPs gene in examined cows respectively and subsequently no carrier was identified.

Genome scan to map quantitative trait loci (QTL) is one of the efficient strategiesfor molecular dissection of complex traits. QTL mapping is the first step toward thedetection of genes responsible for quantitative traits variation. The objective of the presentresearch was to identify QTL influencing carcass weight in cattle. Six Limousin × Jerseycrossbred sires were mated to both Jersey and Limousin dams producing 782 backcrossprogeny. Six sires and all the progeny were genotyped for 189 microsattelite markers.Carcass weight (CWT) was pre-adjusted to account for known fixed effects including,slaughter group, sex, year, herd, dam breed, birth type and age of dam. Residuals werestored after standardization by dividing by the phenotypic standard deviation (σP). Linkagewith standardized CWT was tested, using interval-mapping regression procedure. Threegenome-wide significant QTL located on BTA3, 5 and 14 and two chromosome-widesignificant QTL resided on BTA10 and 17 were identified for CWT. QTL located onBTA14 was segregating in all the six families. The QTL effects raged from 0.4 to 0.8 inunits of phenotypic standard deviation, thus the experiment had only a power to detectmedium to large QTL.