مجله زیست فناوری گیاهان زراعی
پیاپی 4 (بهار و تابستان 1392)

Rice is one of most important crops feeding about half of the world population. Phosphorous is one of limiting factors of rice growth and its deficiency substantially decreases rice yield. In this study، we aimed to identify biochemical mechanisms of rice adaptation to phosphorous deficiency in leaf and root. We compared the metabolites in parental lines، Nipponbare، and its near isogenic line (NIL6-4) containing a major QTL for phosphorous uptake (PUP1) on chromosome 12. Phosphorous deficiency resulted in significant decrease in number of tillers and fresh weight in both parental line and its near isogenic line، however، this reduction was more pronounced in the parental line. Analysis of the level of several soluble sugars and activity of enzymes involved in energy production revealed that phosphorous deficiency could lead to some changes in glycolysis pathway in rice near isogenic line so that the plant could cope with the ATP shortage. It is most likely that enhancement of this biochemical pathways may increase rice adaptation to phosphorous deficiency and consequently increase plant production with less phosphorus fertilizer required.

Due to the importance of mating system in plant fertilization ability، and in order to understand the genetic basis of floral traits associated with mating system in rice including pistil، stamen and glume، these traits were analyzed using a F2:3 population drived from a cross between Iranian cultivar Gharib × Khazar. Quantitative trait loci (QTLs) affecting floral features were detected by Composite interval mapping using a linkage map constructed by using 111 SSR markers. Rate of exerted stigma، stigma length، stigma breadth، style length، anther length، lemma length، palea length، lemma thickness، palea thickness، lemma width and palea width were recorded. As many as 38 QTLs were detected to be associated with 11 traits. A total of 10، 5 and 23 QTLs were detected for trait related to pistil، stamen and size and shape of geumele، respectively. The result obtained revealed that QTLs of qSYL-1، qSYL-6 and qSTL-2a were able to explain 25. 99، 30. 67 and 24. 61% of the total variation of style length and stigma length and distinguished as major effect QTLs. Through the identification of these QTLs، plant breeders would be able to gain more and deeper understanding and insights into the genetic basis of the traits associated with the combining ability in rice cultivars.

Acetyl transferases are enzymes responsible for enzymatic transfer of an acetyl group to suitable receptor molecule by using acetyl CoA as donor. Acetyltransferase reaction is involved in biosynthesis pathway of some important secondary metabolites such as antibiotics، as well as in their detoxification. Trichothecenes are significant secondary metabolites produced by the plant fungal phatogens Fusarium ssp. Such as F. sporotrichioides and F. graminearums. These fungi possess specific genes in their genomes encodeinge acetyl transferase enzymes are affecting trichothecene. In this study، the gene encoding acetyltransferase from the fungus F. sporotrichioides، TRI 101، was cloned and transferred into tobacco plant as model plants and the effect of the enzyme on the detoxification of deoxynivalenol (DON)، a well known trichthecene، was investigated. In addition it was shown that، in comparison whit the roots of wild type plants، transgenic roots grew normally in the deoxynivalenol-contained medium.

In order to evaluate the quality characteristics and seed storage proteins، 11 durum wheat genotypes as well as Eagle، Falat and Verinac genotypes were Chosen. Eight quality traits including hardness، grain quality، Zeleny number، dry gluten، wet gluten، bread mass، grain moisture، water absorption and protein content were measured. For separation of glutenin subunits SDS-PAGE method was used. The correlations between protein content and zeleny number، hardness، dry gluten and wet gluten were significant and positive. On the other hand، there were significant and negative correlation between protein content and bread mass and moisture content. The stepwise regression results indicated that dry gluten was the trait most related to protein content since it explained 90% of protein variation. The high molecular weight Glutenin subunits (HMW-GS) at the Glu-A1 locus، the 2* allele was observed in the Eagle، Falat and Verinac and three genotypes (Kc-525، Wc-3122، Wc-45505). At the Glu-B1 locus، the 7+9 was observed in Falat cultivar. The 17+18 allele was presented in Eagle، Verinac and 6 genotypes (TN-12590، Kc-3638، TN-12501، Kc-525، Wc-3122، Wc-45505). The 7+8 allele also was observed in two genotypes (TN-12595، TN-12567). Cluster analyses of qualitative traits، the genotypes were divided into 3 groups. The findings of the present study could be utilized in breeding programs aimed at improving durum wheat.

Under stress conditions Reactive Oxygens Species (ROS) are produced and accumulate in plant leaves as a results of the oxidation of important cellular components like proteins، chlorophylls and lipids. Vitamin E is the collective term for tocochromonals. This lipid-soluble substance acompanied by carotenoids، glutathion and other antioxidants and has an important role in keeping the integrity of photosynthetic membranes. Tocopherols and tocoterienols are amphipathic molecules and are able to detoxify ROS and lipid peroxyl radicals in lipophilic environments. Hemogentisate phytyl transferase (HPT) is the key enzyme in the vitamin E biosynthesis pathway. To silence HPT and invesitgate its role in tocopherol production RNAi thechnique was used and the results obtained revealed that tocopherol content was decreased in derived lines.

Rice is the main source of carbohydrates for more than a third of the world''s population. It is also a principal food stuff for the Iranian people. In this study، AFLP markers were used to evaluate and fingerprint a number of rice (Oryza sativa L.) genotypes، including 28 Iranian local varieties and 19 exotic varieties. Using 10 primer combinations، 675 bands were obtained out of which 429 bands (63. 5%) showed polymorphism. Among the used primers، E-TTG، M-CAT with107 bands and E-AGG، M-CTG with 34 bands had the highest and the lowest band numbers، respectively. Average polymorphism information content (PIC) was at 0. 34. The best primer combination to differentiate rice samples were E-TTG، M-CAT with the marker index of 24. 1. The average genetic similarity based on Nei coefficient، was estimated at 0. 67 (0. 97 to 0. 40). The dendrogram obtained by using the UPGMA determined three main groups among the investigated varieties which was in concordance with the PCR analysis results. In conclusion، AFLP markers could provide unique fingerprinting patterns for all the studied varieties. The finding of this study could be used in inbreeding programs to produce hybrid and promising varieties based on the genetic distances and the identification of heterotic groups.

In this study، an experiment was designed for optimization of mutation application on microspore embryogenesis of canola، regeneration of embryos and producing haploid plants، from Hayola 401 and Hayola 402 hybrids using EMS mutagen treatments. EMS stocks were prepared for 0. 1، 0. 2 and 0. 3 percent using NLN13 culture medium and then microspores were cultured in NLN13 medium. Then، they were stressed by heat shock (30°C for 14 days). The results showed that in both hybrids by 0. 1 % mutagen treatment for 90 minutes، the highest numbers of embryos achieved. So in the 90 minutes durations all of three applied concentrations from EMS and the control had significant differences and by increasing the concentration along this duration، fewer embryos were achieved. Afterwards، embryos were transferred to B5 medium containing gibberellic acid and incubated at 25°C and after full growth they were transferred to B5 medium without gibberellic acid. The results in both hybrids showed that the highest numbers of regenerates were produced when EMS (0. 3% for 90 min) was applied to isolated microspores.

Using Agrobacterium rhizogenes to induce hairy root cultures is a useful method to increase the production of secondary metabolites especially medicinal compounds in vitro in various plant species. Hairy root cultures are fast growing and highly branching and due to the higher amount of metabolites synthesized per unit of biomass، possess the same or greater biosynthetic potential for secondary metabolite production compared to the normal roots. In this research the amounts of total phenolics and chlorogenic acid were determined in hairy root clones induced in cotyledonary leaves of Cichorium intybus by A4، A13 and 15834 strains of A. rhizogenes، as well as in the control (untransformed) roots. The results obtained indicated that the absence of chlorogenic acid in all the studied clones led to a significant increase in total phenolics in hairy root clones induced by A4 and A13 but a significant decrease in the 15834-induced hairy root. This study revealed the role of bacterial strains in biosynthesis of phenolic compounds، and therefore، selection and application of the best strain of A. rhizogenes could be regarded as an important strategy for increasing phenolic compounds production in hairy root cultures of C. intybus.

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.

Tea (Camellia sinensis L.) is an important beverage crops containing caffeine worldwide. Releasing cultivars with high yield and quality demands knowledge about tea genetics and cytogenetics. Karyotypical study of nine tea genotypes was carried out using squash method on root tips. The best microscopic slides was first obtained using root tip of tea cuttings pretreated by α-bromo Naphthaline for 8 h، fixed by farmer solution and then stained with hematoxilin. Eight morphological traits were taken into consideration، each within three meiotic chromosomes using Micromeasure software. Analysis of variance showed significant differences (1%) among genotypes، chromosomes and the interactions، for all of the measured parameters. All studied teas were diploid and had 2n=2X=30 metacenteric and submetacenteric chromosomes. Total length of chromosomes ranged from 1. 10 to 4. 42 μm. Also، in terms of total length of chromosomes، genotypes 4 and 8 had the highest correlation and genotypes 2 and 9 had the lowest. Moreover some cytogenetic statistics was used in order estimate the karyotypic symmetry of genotypes. The results obtained showed that the genotypes 1 and 2 had the most asymmetric and genotypes 3 and 8 had the most symmetric، based on the TF%. Ordination based on principal components analysis (PCA) revealed presented that more than 97% of total diversity with two components was described. Centromeric index and long arm length had the most roles in the components، respectively. Cluster analysis using UPGMA method، also grouped the genotypes in four clusters and 100 promising clones were separated from the others، similar to result of PCA Bi-plot، relatively.

Production of haploid plants was studied in summer squash via induction of parthenogenic embryos. Female flowers were pollinated with anthers irradiated by different doses of gamma ray (25، 50، 75، 100 and 200 Gray) and induced embryos were rescued and cultured in specific medium. The results achieved showed that the highest number of embryos was obtained in 50 and 75 Gray doses (82%)، however، no embryo was produced at 200 Gray. Gamma ray doses and embryo stage had significant effect on frequency of embryo and plant regeneration. Highest embryo regeneration and haploid formation (27 plant regeneration and 11 haploids formation، respectively) were recorded at 50 Gray. All amorphous embryos produced only diploid plant، though 29. 17، 33. 33، 57. 14، 66. 67، 100 and 100 percent of plants derived from cotyledon، heart، torpedo، arrow-tip، torpedo-tip and globular embryos respectively، were haploid. Based on this study، out of the 7744 extracted seeds، 127 embryos and 44 plants were regenerated; among those 17 plants were identified as haploid plants using chloroplast counting، Flow-Cytometry technique and morphologic traits evaluations.

In this study، effects of gamma irradiation doses on spore germination of Trichoderma harzianum and its effects on morphological and antagonistic capability of the mutants to control Rhizoctonia solani have been evaluated. Spore suspension of Trichoderma was gamma-radiated by 0، 50، 100، 150، 200، 250، 300، 350، 400 and 450 Gry Gamma ray and the effects on mycelial growth were evaluated by irradiation with 0، 400، 800، 1200، 2000 and 2500 Gry. The results obtained showed that 450 Gry gamma radiations completely blocked the spore germination and 250 Gry was found as the optimum dose to induce mutation in Trichoderma. Furthermore، gamma irradiation could change the morphological characteristics such as: colonies shape and color، sporolation and mycelia growth rate. Dual culture test proved that، the mutated isolates had statistically more antagonistic capability against R. solani than its parental strains. According to the findings of the present study، bio-control capability of Trichoderma could be improved through gamma radiation.

Potato virus A is one of the most important viruses infecting potato in the world. During spring and summer of the year 2011، a total of 280 symptomatic and 463 random leaf samples، and 1186 tuber samples were collected from potato fields located in Khorasan-e-razavi and Markazi provinces، Iran and tested for PVA infection using DAS-ELISA method. Based on the results obtained، PVA infection was recorded in 39 and 11 % of symptomatic leaf samples، 23 and 6 % of random leaf samples and 17 and 13 % tuber samples in Markazi and Khorasan-e-Razavi provinces، respectively. Morever، biological properties of the selected PVA isolates were studied using host range studies on 10 plant species. Four PVA isolates were selected and their coat protein (CP) gene was amplified by specific primers using RT-PCR and their nucleotide sequences were determined (KF152950-3). The CP sequences of four Iranian and 37 Non-Iranian (from other parts of the world) PVA isolates were compared and a phylogenetic tree was reconstructed using Neighbor Joining-NJ method with 1000 bootstrap value. The PVA isolates in the phylogenic tree were clustered in two main groups (I and II) where group I had two subgroups (IA and IB). Three Iranian PVA isolates (Ar2، Kh4 and F2 all from Markazi province) were grouped in IA subgroup and showed highest similarity with two isolates from Germany and Netherlands (Y11427 and X91968) and the other Iranian PVA isolate (Gh4 from Khorasan-e-Razavi P.) was grouped in IB subgroup showing the highest similarity with an isolate from China (DQ309063). Comparison of the deduced amino acid (aa) sequences of CP among the four Iranian and the other PVA isolates revealed substitution of 2 to 7 aa mainly in N terminal of CP. This is the first phylogenetic study on Iranian PVA isolates and also the first report of PVA infection in Markazi province. This study showed variation among PVA isolates in Iran. These data could to be considered in potato breeding programs in order to achieve PVA resistant cultivars.

Today with appropriate understanding of economical، ecological، cultural and social importance of biodiversity، significant progresses have been made toward identification، quantification، finding distribution patterns and genetic relationships of this diversity. In addition، analysis of genetic variation of various aspects such as distribution of allelic diversity، genetic structure and kinship relationships between and within populations، individuals and species is one of the main concerns in biological sciences. In this regard، and with respect to the importance of identification، preservation and maintenance of these genetic pools، to ensure the permanent existence of them and using those resources as a tool for facilitating management strategies and breeding processes، the efficiency of some different genetic and genomic methods including genome and transcriptome based microsatellites have been evaluated in some crop plants، i. e. saffron، and some species belonging to genus Prunus and Punica. Through the development of different molecular markers used in the above-mentioned studies، genome-based microsatellite markers have significantly improved our knowledge on the processes related to habitat segmentation and small populations، distribution of allelic diversity، patterns of germplasm management and finally genetic relationships in the field of genetic conservation. Recently، availability of next generation sequencing tools provided access to huge amount of transcriptomic and genomic sequences. This has allowed us to، a) investigate the diversity of gene functions caused by habitat segmentation، b) assess diversity of responses to biotic and abiotic stresses as well as environmental changes and، c) identify suitable markers to be used in studies such as marker-assisted selection. Here we discuss how the integration of genomic and transcriptomic variations backed up with new bioinformatic tools could improve the identification of relative influences of genetic and environmental threats and open up new frontiers in conservation studies.

Exposing plants to both biotic and abiotic stresses could lead to increased reactive oxygen species and in turn could induce oxidative stress. In order to increase scavenging capacity of oxidative agents، the different plant antioxidant activities also are arising. Among those، vitamin E includes a group of Fat-soluble antioxidants، which their synthesis is limited to photosynthetic organisms including plants، alga and cyanobacteria. In this study، the coding region of Arabidopsis Tocopherol cyclase gene; which catalyzes 2،3-dimethyl-5-phytyl-1،4-benzoquinone (DMPBQ) into γ –tocopherol; was introduced into pBin vector containing the coding region of GFP protein. Then، the obtained construct was transformed into tobacco plant through agrobacterium-mediated method. Leaves of 2-3 weak old seedlings were selected as explant and direct regeneration was performed. In order to confirmation of transgenic plants، PCR by using specific primers was carried out. Due to the fact that the pBin vector contains the kanamycin resistant gene، seeds belonging to the T0 transgenic plants were planted on medium containing kanamycin and green seedling were selected as transgenic T1 plant. In order to evaluate the effects of transferred gens on physiological parameters، mature T1 transgenic plant as well as the wild type plants were subjected to drought stress and relative water content was measured.