رضا شیرزادیان خر مآباد

Cysteine is an important precursor for defense compounds in plants. The enzyme cysteine synthase (OASTL; EC 2.5.1.47) catalyzes the final stage of cysteine biosynthesis and need cofactor Pyridoxal-Phosphate) PLP) for its function. The use of bioinformatics tools to find genes with functional domain PALP (Pyridoxal-Phosphate dependent enzyme) in Arabidopsis and rice identified 20 and 19 OASTL-Like genes. Physicochemical, phylogenetic, gene structure, conserved motifs, Cis regulatory elements, post-transcription expression regulation and expression profile of OASTL-Like genes in Arabidopsis and rice were investigated. The identified genes have been categorized into two major clusters and several subgroups. The first cluster consists of 20 members all of which have a related function to cysteine synthase and The second cluster has 19 members. Structure of the intron-exon, the composition and distribution of motifs of those genes were similar confirming the phylogenetic classification indicating the high conservation of genes. Evaluation of promoter region OASTL-Like genes identified 47 types of regulatory elements in Arabidopsis and 48 types in rice. Regulatory elements G-box, ARE and ABRE have the highest frequency. Examination of the mRNA sequence of OASTL-Like family genes in Arabidopsis and rice showed that these genes target 87 and 105 different miRNA molecules, which regulate gene expression at post-transcriptional. The expression profile of OASTL-Like genes indicates the very diverse function of these genes in different developmental stages, in responds to abiotic stresses. The results of this study provide basic and valuable information about OASTL-Like genes in plants.

The mutant plants old3-1 (onset of leaf death 3-1) have a point mutation in the AT4G14880 gene. This gene encodes the cytosolic cysteine ​​synthase enzyme (OASTL-A1). Cysteine ​​is a sulfur-containing organic compound and a precursor of defense compounds, and the OASTL-A1 enzyme plays a role in the last step of its synthesis. The old3-1 mutation causes a change in the structure and activity of the cysteine ​​synthase enzyme, and the old3-1 mutant plants suffer premature cell death after 14 days under 21°C long-day conditions. In this research, the old3-1 mutant was compared with mutants B40-12, old3-2 and wild type Ler-0, Col-0 under short-day conditions and 21°C. Based on the phenotypic and physiological results, old3-1 plants did not suffer premature cell death and went through different stages of growth and development until flowering and seed production. Examining the activity of catalase and peroxidase enzymes under short day conditions showed that the activity of these enzymes in the leaves of old3-1 is higher than that of Ler-0 and B40-12, which means that in short-day conditions the activity of the enzymes increased. Examining the relative expression of immune system marker genes including GST1, DEFL and PR1 in 22-day-old seedlings old3-1 and Ler-0 under the same conditions (short day and 21˚C) following transferring to long day showed that the expression of the above genes in short day significantly increased, resulting in the survival of old3-1 mutant plants. According to the obtained results, short days improve growth and development conditions and save old3-1 seedlings from premature cell death.

Soil salinity is one of the environmental stresses that causes the accumulation of reactive oxygen species (ROS), and oxidative stress, and consequently, reduces crop growth and production. Antioxidative mechanisms are critical to protect cells from the adverse effects of ROS.

Thhis study was conducted in nutrient solution in Rice Research Institute of Iran, Rasht, Iran in 2019. The enzymatic activity and expression of effective genes on antioxidant defense were examined in two selected mutant genotypes (em3hs290 and em3hs84) tolerant to salinity stress, with Hashemi local cultivar, FL478 (tolerant) and IR28 (sensitive) genotypes. Biochemical traits including the activity of antioxidant enzymes, peroxidase, catalase, and ascorbate peroxidase, and the relative expression of genes encoding transcription factors (SNACI, DREB2B, and DREB2A) and genes associated with oxidative stress (OsAOX1C ،POX1، OsGR1، OsAPX2 and OsGPX1) were also measured and detected using real-time PCR technique.

The results showed that enzymatic activity of peroxidase (POX) in control cultivars (cv. Hashemi and IR28 cultivars) and ascorbate peroxidase (APX) in tolerant mutant genotypes and FL478 cultivar increased significantly. The genes expression associated with salinity stress tolerance also indicated that despite the variable behavior of the genes in the studied mutant genotypes, the expression of OSGR1, DREB2B, OsAOX1C and POX1  genes in studied tolerant mutants was more than susceptible cultivar. Transcript abundance of the OsAPX2 gene was significantly higher in salt-tolerant genotypes under short-term salinity stress and correlated with peroxide hydrogen removal and increased activity of ascorbate peroxidase enzyme.

The lack of similarity in the expression pattern of studied genes between the two salt-tolerant mutant genotypes (em4hs290 and em4hs84)  and  cv. Hashemi showed that the mutation could triger the salt-tolerance mechanisms in mutant genotypes, in comparison of cv. Hashemi, through emhancement of antioxidant enzymes activity in response to salt stress. It seemes that the mutant genotypes may have suitable growth in soil salinity conditions.

Salinity stress affects morpho-physiological and biochemical traits of plants. The transgenic Bt plants play a significant role in pest control, but their response and ability to cope with environmental stresses still need to be evaluated. Therefore, effect of salinity stress at 0, 50, 100, 150, and 200 mM on morphological, physiological, and molecular traits of T3 transgenic tomato plants containing cry1Ab gene (CH-Falat-Bt) was investigated and compared with that of the non-transgenic control (CH-Falat). Evaluation of the morphological traits (leaf area, root length, fresh and dry weight of roots) at different salinity levels revealed that CH-Falat-Bt transgenic plants are more tolerant to salinity stress compared to CH-Falat non-transgenic plants. The chlorophyll content at 150 and 200 mM salinity levels was 12 and 9% plants, respectively. Moreover, the amount of RWC, carotenoids, proline and soluble sugars increased significantly in transgenic plants as salinity levels increased. The relative expression of SOS1 and SOS2 genes showed a significant increase in all salinity levels in CH-Falat-Bt transgenic plants compared to CH-Falat non-transgenic plants. The amount of electrolyte leakage in the transgenic plants was significantly reduced compared to the non-transgenic plants. The results of morphological, physiological, and molecular investigations of CH-Falat-Bt transgenic plants confirmed that the undesirable effects of salinity stress on transgenic plants is much less than non-transgenic ones. in general CH-Falat-Bt transgenic plants are more tolerant to different applied salinity levels than the wild variety.

Salinity stress is one of the most severe constraints limiting rice production worldwide. Thus, the development of salt-tolerant rice can provide increasing food demand due to climate change effects.

To investigate the reaction of mutant genotypes to salinity stress in the seedling stage, 309 selected mutant genotypes selected in the third generation along with Hashemi local cultivar and FL478 (resistant) in two levels of NaCl salinity (0 and 10 dS/cm) were evaluated as a completely randomized factorial design with two replications. Growth parameters like root length, shoot length, root fresh and dry weight, shoot fresh and dry weight and plant biomass were measured after 14 days of exposure to two levels of stress namely, non-stress (EC ~ 1.2 dS/m) and saline stress (EC ~ 10 dS/m) in hydroponics at seedling stage. The Stress tolerance index (STI), Stress susceptibility index (SSI), Mean productivity (MP), Stress tolerance (TOL) and Geometric mean productivity (GMP) for each genotype was calculated for all the traits.

The results of analysis of variance showed a significant difference between genotypes for all traits that indicated genetic diversity between them. A wide range of genetic variability was observed among genotypes for studied traits that root traits were identified as the best descriptors for tolerance to salt stress conditions. Results of correlation coefficients among the indices showed that STI, HMP and GMP indices were the most suitable resistance indices. Salt stress response indices (SSRI) were used to classify the number of 144 mutant genotypes; 25 mutant genotypes (17.4%) were identified as salt-sensitive, 46 (32.6%) with Hashemi parent in salt-sensitive group, 41 (32.6%) with FL478 each in salt-tolerant group, and 30 (20.8%) as highly salt tolerant. Among the mutant genotypes, four mutant genotypes em3hs290, em3hs292, em3hs165 and em3hs84 were identified as the most tolerant genotypes based on stress tolerance indicators, minimum leaf tubing, high biomass rate and better stress compensation ability. Also, the mutant genotype em3hs31 was introduced as the most sensitive genotype with a minimal performance at the stress level.

Induced mutation of EMS has desirable effect on creation of salinity tolerant mutant genotypes and the studied indices can utilize for separating of salinity tolerant mutant genotypes in rice mutant populations. This mutant population could serve as a valuable genetical resource in the development of novel salt-tolerant varieties for the salinity prone regions under rice cultivation.

High temperatures causes serious damage to plants, including disruption of cell hemostasis, slowness or stagnation of growth and development, and even death. When plants are exposed to high temperatures, heat shock proteins (HSP) are induced in the cell. Among HSPs are Small heat shock proteins (sHSP), which act as chaperones. They bind to proteins that have been exposed to heat stress and prevent them from incorrectly folding. The Artemin protein isolated from Artemia urmiana has a a-crystallin domain, which is characteristic of sHSP. In order to characterize the functional genomic roles of the protein in plants, artemin gene was transferred to Arabidopsis. A statistical analysis using the factorial design method was performed including two independent transgenic genotypes (art-1 and art-2) along with a wild genotype Col-0 under heat stress at 45°C. Results showed that the interaction between heat stress factors and genotypes was significant at the 1% level for most traits including germination, seedling wet and dry weight, seedling length, total protein content, catalase enzyme activity, and malondialdehyde content. All the components of germination were adversely affected by the application of heat stress. However, the transgenics still had a significantly higher seed germination and plant growth than the wild-type plants. As a result of heat stress, transgenic plants had significantly higher catalase enzyme activity and total protein content, and lower malondialdehyde levels compared with wild type plants. The results indicated that Artemin transgen in plants may cause significantly higher plant resistance to heat stress and increase plant yield.

A few small molecular weight signals, including jasmonic acid (JA), salicylic acid (SA), and ethylene (ET), regulate the expression of defense-related genes in plants. These signals serve to inhibit the activation of plant defense genes against aggressors and can manipulate the plant's defense signaling pathways. In this study, the impact of acetosyringone on the induction of virulence genes was examined in Agrobacterium tumefaciens A348 (MX311) and A348 (MX243) at three different levels: 0, 100, and 200 μM. The concentration that demonstrated the highest induction of virulence genes was then used for transforming Arabidopsis mutants using A. tumefaciens EHA105, with the aim of inducing virulence genes. Results revealed that virD2 expression reached its peak at 200 μM acetosyringone, while virB2 expression was highest at 0 μM. Additionally, transformation experiments indicated that the SA mutants (nahG) exhibited the highest transformation efficiency, while the control plants (Col-0) displayed the lowest efficiency. Therefore, the efficiency of gene transfer in SA-suppression mutants suggests a more significant role for SA in plant defense against pathogens compared to the other hormones. Enhancing gene transfer efficiency in these mutants could unlock the potential for increased expression and production of recombinant proteins compared to the wild type.

 Abiotic stresses, especially drought, have a negative effect on crop growth and production. Plants display a variety of hysiological and biochemical responses both at the cellular and whole organism level upon sensing drought stress. Drought tolerance levels and antioxidant protection mechanisms were evaluated for 41 mutant genotypes seedlings (M3) induced of the ethyl methanesulfonate on Hashemi rice cultivar.

Drought was imposed in hydroponic culture with polyethylene glycol 6000 (PEG 6000) at the level of -10 bar using factorial experiment as completely randomized design. In this experiment the morphological characteristics of relative humidity content, electrolyte leakage, proline and antioxidant enzymes were investigated.

 All the studied genotypes showed apparent decreases in growth characteristics under drought stress. Based on different morpho- physiological parameters, two genotypes M29 and M122 were identified as promising drought tolerant mutant genotypes. They exhibited the maximum increase in root length without any significant changes in its root weight and root volume compared with the parent under stress and also showed better performance for various physiological parameters such as relative water content, cell membrane stability and proline content upon water stress under hydroponic conditions. Concomitantly, the activity of antioxidant enzymes catalase, peroxidase and ascorbate peroxidase in the drought-tolerant mutant genotypes increased markedly during drought stress, while decreased by drought stress in the drought sensitive mutant genotypes. Also, M31 and M106 mutant genotypes were introduced as the most susceptible genotype with minimum performance at stress level.

 In this study it was found, proline accumulation, increase of root biomass, increase of membrane stability and antioxidant enzymes such as POX, APX and CAT during water stress are contributing to drought tolerance conditions and could be used in screening for drought tolerance. The mutant genotypes identified in this study will be useful for further dissection of water stress tolerance in rice.

Agrobacterium tumefaciens-based plant transformation is a natural and ideal way of introducing genes into plant genomes. The system is based primarily on tissue culture techniques, including cell differentiation and plant regeneration, which might produce somatic cell mutations. In the present research, wheat plants were transformed by a non-tissue culture approach. Accordingly, mature embryos were inoculated with A. tumefaciens at an early stage of germination. A variety of different treatments, such as Agrobacterium strains (EHA105 and LBA4404 harboring pCAMBIAl105.1R), levels of glucose, concentrations of acetosyringone (0, 50, 100 and 200 µM), and types of wheat cultivars (Azar2, Alvand, and Sardari) were studied. The transformation efficiency was determined by using the number of resistant leaves to hygromycin, histochemical GUS analysis of leaf tissues, as well as PCR analysis of three transgenes located within the T-DNA region. The results showed that the maximum efficiency was obtained when 200 µM acetosyringone was used in combination with 15% glucose in the induction medium. In addition, the relative expression analysis of virulence genes by qRT-PCR revealed that VirB2 and VirD2 were significantly up-regulated when 200 µM acetosyringone and 15% glucose were used as inducers and carbon source, respectively. Therefore, Vir genes inducing factors as well as a three-step culture of Agrobacterium should be considered as major elements for any wheat transformation protocol. The putative transgenic T1 seeds were soaked and germinated in hygromycin solution, and the seedlings were further analyzed with the aforementioned methods. Based on the results, a modified Agrobacterium-mediated transformation protocol is presented. The current results suggest an inexpensive, quick and efficient approach for wheat genome transformation.

Salinity is one of the limiting factors in many crops including rice production. The objective of this study was to investigate the response of 89 recombinant inbred lines derived from a cross between two Iranian rice cultivars, Tarom-Mahalli (indica) and Khazar (indica), under non-stress and 8 dS.m-1 salinity stress at vegetative stage conditions. The experiment was carried out as pod experiment under open air conditions in a completely randomized design with four replications. The results of combined analysis of variance under non-stress and salinity stress conditions showed that the the effect of line and line×stress interaction for all the studied traits was significant, indicating different reaction of the lines under two conditions. The results of simple analysis of variance also showed that the difference between lines in both conditions was significant for all traits at 1% probability level. Correlation coefficients among traits indicated that the highest correlation coefficient was observed between biomass and stem dry weight under both conditions. Stepwise regression analysis for biomass under non-stress conditions showed that root length, root to shoot dry weight ratio, number of tillers per plant at 120 th day and plant height at 120th day were the most important traits influencing biomass, respectively, while under salinity stress conditions, root area and root volume in addition to these four traits, were also identified as effective traits on biomass. Factor analysis also showed that three and five independent factors explained the correlation between biomass and the other traits in the studied lines under non-stress and salinity stress conditions, respectively. Cluster analysis using Ward’s minimum variance method under non-stress conditions divided the lines into four groups which the fourth group was consisted the lines with higher values than total average for most traits. Under salinity conditions, the lines were divided into three groups and the lines into first group had the highest biomass and the lowest genotypic score and were tolerant to salinity stress. In total, the results of current study showed that the lines 6, 9, 13, 14, 17, 18, 23, 24, 34, 39, 44, 45, 68, 79 and 80 had the higher values for most the studied traits than the other lines, in addition to higher biomass, and could therefore be considered as salinity tolerant lines in future researchs.

Herbicide-resistant plants are one of the most common plants that comprise the majority of the total population of transgenic plants. Glyphosate is an herbicide that controls a wide range of plant species. Position of these herbicides reaction is 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) that only exists in plants and some bacteria. This herbicide was known to be suitable and safe for the environment. However, it can also damage crops in farming systems, therefore, it is used before planting. Today, using genetic engineering techniques, the herbicide-resistant gene was isolated and transferred to different crops. The cultivation of herbicide-resistant crops to is increasing. This study, is a review on studies about herbicide-resistant crops.

Salinity is an important limiting factor in the production of more plants, including rice. Due to the limited amount of cultivated area, identification of tolerant genotypes to environmental stresses and especially salinity is very important. The aim of this study was to investigate the genetic diversity among 114 recombinant lines derived from the intersection of local Tarom × Khazar cultivars under non stress conditions and salinity levels of 8 dS/m in reproductive stage in a completely randomized design. Combined analysis of variance showed that the differences between lines was significant for all traits. Genotypic variation coefficients also showed that the highest genetic variation among the evaluated recombinant lines was related to the number of panicles per plant. In contrast, days to 50% flowering showed the least genetic variation among these lines. In non stress and stress conditions, the highest genotypic and phenotypic correlation coefficient was observed between grain yield and number of fill grain in seedlings. Based on the cluster analysis of grain yield, the lines were classified into four groups under normal conditions and were classified into three groups under salinity conditions. The third-party lines in both cases had a higher average than the overall average. In general, the results of this study showed that there is a significant genetic variation between the studied lines in terms of salt tolerance and this variety can be used in subsequent corrective programs. Accordingly, lines 83, 81, 56, 39, 37 and 89 were the most sensitive lines and lines 107, 101, 16, 100, 84, 98, 47, 32, 14, 29, 95, 63, 5, 49, 92 and 10 were the most tolerant lines to salinity stresses of 8 dS/m and they also had higher yields and yield components. Strained lines are proposed directly for cultivating saline or for transferring salt tolerance to commercial cultivars through future breeding programs.

African violet as one of the important economic ornamental plants could be propagated through tissue culture technique in a short time and limited space. The effect of different growth regulators on shoot production, leave number, root number and rooting time was measured. 'Pretty Miss Kelly' young leaves were collected, and after disinfection, were divided into pieces with dimensions of 1cm*1cm. Therefore, effect of different combination of NAA, BAP, and IAA on shoot regeneration from leaf segments was monitored. Moreover, the effects of various combinations of BAP and AdS has been evaluated on the number of leaves. Subsequently, different root induction mediums including ½ MS with 0.005 mg/l NAA, MS without growth regulators and sterile sand were investigated. The obtained data was analysed by factorial experiment in a completely randomized design with 4 replications. The results showed that 0 mg/l NAA or 0.1 mg/l NAA in combination with 0.1 mg/l BAP and also 0 mg/l IAA in combination with with 0.1 mg/l of BAP are most suitable for shoot production. The best level of AbS and BAP regarding leaf number was inturn 15 mg/l and 0.2 mg/l. A better performance for root induction happened in sterile sand with an average of 25 roots per plantlet. In the case the root induction time, ½ MS with with 0.005 mg/l NAA with an average of 10 days was the best. Therefore, the most appropriate nutrient mediums in various stages for In vitro micrpropagation of African violet from leaf segments was identified.

The most effective way to produce a plant resistant to glyphosate is manipulation of EPSPS enzyme in order to reduce its affinity to this herbicide. It is one of the vital enzymes in the shikimate pathway, which is responsible for producing aromatic amino acids and various secondary metabolites in plants and bacteria. Without an active enzyme, the organism will not be able to survive. In the present study, one of the important domains in the EPSPS enzyme was modified by site-directed mutagenesis using mega-primer method and one tube approach. Glycine in position 96 was modified to Alanine which was sub-cloned along with the wild-type gene into pPZPY122 plant binary vector. Hashemi cultivar of rice (Oryza sativa) was used for transformation using EHA105 strain of Agrobacterium tumefaciens by in planta method. T2 transgenic plants separately were evaluated to resistance to the gentamicin and glyphosate. Also, positive gene expression was confirmed by Quantitative PCR. Therefore, based on the results, these plants showed significantly a high degree of resistance to the herbicide.

Sorghum, in spite of its great tolerance to drought stress, suffers from grain yield loss due to pre and post flowering -drought stress conditions. NAC TFs play key roles in Sorghum drought adaptation. In this study, NAC protein family data was collected from databases. Then, hidden Markov model profiles of NAM domain (PF02365) was obtained from Pfam database and used to find the putative NAC members against Sorghum proteins. Totally, 183 protein sequences encoded by 131 gene loci were identified. The unrooted phylogenetic tree was constructed based on NAC domains of Sorghum and 11 known NAC domains of other plants using the Neighbor-Joining method, which classified the family into 15 subfamilies. 13 members of the NAC protein family of Sorghum joined to the SNAC subfamily of other plants, which are expected to be involved in abiotic stress tolerance. 14 different stress and hormone responsive regulatory elements were predicted in promoters of SNAC subgroupgenes. To study the expression pattern of these genes, two extreme Sorghum cultivars including Kimia and Sepideh were planted based on Split-plot Randomized Complete Block Design with three replications in the field. Irrigation was performed in two levels including normal irrigation and drought stress (water holding from anthesis). Based on the SbSNAC expression pattern, we predict that some members are involved in response to drought stress at post-flowering stage as positive (3 members) and negative transcriptional regulators (3 members). As well, some of them play role in leaf senescence (2 members) and metal remobilization processes (2 members).

Tomato leafminer (Tuta absoluta) is one of the important pests of tomato in Iran. It causes serve losses to tomato yield between 50 to 100% in the world. The cryIAb gene has been introduced into many plant species, including maize resulting in protection of the maize plants against corn borer larvae. In most studies, constitutive promoters such as CaMV35S were employed for genetic transformation; however the constitutive expression of genes led to changes in plant metabolic pathways due to permanent energy consumption in plants. Since, wound inducible promoter MPI (Maize Protease Inhibitor) posses more efficiency and strength than CaMV35S promoter. Therefore, in the current study, transgenic tomato (cv. Falat) plants harboring cryIAb gene under control of the MPI promoter were developed for the first time. The MPI promoter was isolated from maize and cloned into pPZP122 expression vector replacing the CaMV35S promoter. The cryIAb gene was isolated from pCIB4427 and cloned in pPZP122:MPI:cryIAb and the resulting construct was transformed into Agrobacterium AGL1 strain using In planta approach. Initial selection of the transgenic plants was carried out in media culture containing gentamicin. PCR analysis confirmed the presence of transgene in gentamycin-resistance plants in the first and second generations by rate of 62.5% and 75.58%, respectively. Protein dot blotting using anti-CryIAb polyclonal antibody confirmed the presence of protein in the second generation of transgenic lines. Based on the result of Tuta bioassay, transgenic plants demonstrated an enhanced resistance against Tuta. Thus, the wound inducible promoter MPI can be used in genetic transformation of crop plants if insecticidal protein-encoding genes (such as different types of cry) are used and therefore, it is important to be used when plants asked to express only when are being attacked by insect pests.

The virulence genes (vir) of Agrobacterium tumefaciens induces by many factors such as specific plant phenolic metabolites and sugars. A number of these factors act synergistically with acetosyringone and causing high expression levels of vir genes. In present research, the induction of virB2 and virD2 gene promoters, were investigated in A348 (MX311) and A348 (MX243) Agrobacterium variants, respectively. The promoter sequences from these vir genes have been fused with a promoterless lacZ gene in a cassettes carrying Tn3. A three-day culture of Agrobacterium was performed, which was included a vegetative growth followed by an induction step. Sugar treatment of glucose, mannose and deoxymannose were used in combination with different concentrations of acetosyringone in the two biological and three technical replications. According to the results, the highest activity of β-galactosidase enzyme attained when the mannose of sugar was used in combination with 50 µM acetosyringone for bacterial strain carrying virB2::lacZ construct. The mannose of sugar treatment in combination with 100 µM acetosyringone treatment, for bacterial strain carrying virD2:: lacZ, induced the highest enzyme activity. The monosaccharides in order of descending vir::lacZ activity in the absence of acetosyringone: glucose > mannose > deoxymannose. According to our observations, we suggested that the mannose of sugar treatment with 100 µM acetosyringone could be utilized for obtaining strong induction of Agrobacterium vir genes in an induction medium.

A gene family called Strictosidine synthase like (SSL) exists in Arabidopsis thaliana genome. Orthologs gene in Catharanthus roseus is involved in monoterpenoid indole alkaloids biosynthesis. A member of gene family (SSL6) has been induced by various biotic and abiotic stresses. To further analyse of the functional role of the gene in response to salt stress, the SSL6 T-DNA insertional mutant (ssl6) was used in response to 0, 100 and 200 mM NaCl. Therefore, several morphological, physiological and molecular traits including the percentage of seed germination, root length, Catalase (CAT), Peroxidase (POD) and Superoxide dismutase (SOD) enzyme activity, and relative expression levels of AAO3, RD29A, NCEDD3 and P5CS1 were measured. The obtained data have been analyzed using a factorial experiment (with two factors) based on completely randomized design (CRD) with three replications. The obtained results demonstrated that the percentage of germination, root length and activity of SOD, POD and CAT enzymes were significantly higher in ssl6 genotype when compared with the wild type Col-0. The expression level of responsive genes at 3 and 6 h after salt stress treatment were significantly increased in ssl6 mutant genotype compared to Col-0 genotype. Results of this study for the first time reported that SSL6 genes in involved in plant responses to salinity stress and suppression of SSL6 gene resulted in increased tolerance to salt stress in Arabidopsis.

In eukaryotes cells, genomic DNA in combination with histone proteins is formed the chromatin. Histone chaperones affect the gene transcription via altering in DNA accessibility. In contrast to their animal and yeast counterparts, not much is known about plant histone chaperones. Nucleosome assembly protein (NAP) family histone chaperones are conserved throughout eukaryotic genomics. NAP is an integral component in the establishment, maintenance, and dynamics of eukaryotic chromatin. They transfer histones into the nucleus, assemble nucleosomes, and promote chromatin fluidity, thereby, affecting the transcription of many genes. In this study, by applying some bioinformatics analysis approaches, six putative NAP genes (ZmNAPL1–ZmNAPL6) were identified in maize (Zea mays) using the released maize genomic sequences. Phylogenetic analysis showed that these ZmNAPLs are classified into two subgroups as found in Arabidopsis and rice. Moreover, it was found that maize NAPL proteins are more closely related to rice. The ZmNAPL genes contained three to eleven introns and were distributed across 5 out of 20 chromosomes in maize. Microarray-based expression analysis of ZmNAPLs showed that there is a tight transcriptional regulation on ZmNAPL genes during the plant development in maize suggesting that they may play a role in genetic reprogramming in association with the developmental process. This study is the first report about NAPL gene family in maize and obtained results provide basic information for future research on the functions of NAPL genes in maize.

Growth, development and productivity of plants are greatly affected by various abiotic stresses. Physiological and molecular studies have shown that naturally occurring plant polyamines (PAs) are involved in conferring abiotic stress tolerance in plants. Polyamine oxidases (PAOs) are FAD-dependent enzymes associated with polyamine catabolism in peroxisomes, the apoplast and the cytoplasm. In plants, increasing evidence supports the idea that PAO genes play essential roles in abiotic and biotic stresses responses. In this study, bioinformatic analysis identified eight putative PAO genes (VvPAO1–VvPAO8) in grape (Vitis vinifera) using the released 12×assemble grape genomic sequences. Phylogenetic analysis indicates that these VvPAOs can be classified into three subgroups as found in Arabidopsis and rice and also reveal that grape PAO proteins are more closely related to Arabidopsis than to those in rice. The VvPAO genes contained zero to nine introns and were distributed across 6 out of the 19 chromosomes in grape. Promoter analysis showed the presence of several cis-regulatory elements related to stress and hormone responses in regulatory regions, indicating their probable role in stress response. Microarray-based expression analysis of VvPAO orthologs in Arabidopsis under abiotic stresses showed that transcript levels of PAO genes were up-regulated significantly by such treatments, indicating their vital roles during stress adaptation. The results obtained provide basic information for future research on the functions of PAO genes in grape.

Strictosidine synthase is a key enzyme in the monoterpenoid indole alkaloids biosynthesis pathway. Proteins with Str_synth domain have been identified in plants, bacteria, insects and even mammalians and called Strictosidine synthase-like due to unknown functional roles. With the Arabidopsis and rice genome sequence completed, SSL genes were also identified in these plants. However, little is known about evolutionary path, gene structure, expansion and function of SSL family in rice. In this study, through bioinformatic analysis, a total of 23 SSL genes were identified in rice genome. A phylogenetic analysis of the SSL genes in rice and Arabidopsis clarified that these genes could be divided into four different groups and the evolutionary paths are different in rice and Arabidopsis. The OsSSL genes contained zero to five introns and were distributed across 10 out of 12 chromosomes at different densities and tandem duplication was a major cause in expanding this family. Promoter analysis showed the presence of several cis-regulatory elements related to stress and hormone response in regulatory region, indicating probable their role in stress response. Microarray-based expression analysis of OsSSL genes indicated that a few number of these genes were widely expressed in various tissues and also in response to some abiotic stresses. This study is the first report about SSL gene family in rice and provides a framework for further analysis of the biological functions of SSL genes in either rice or other crops.

In this study, photochemical and genetic diversity of three yarrow’s populations Achillea wilhelmsii C. Koch of Hormozgan province were evaluated using nine RAPD primers. In general, 112 polymorphic bands were produced from the applied primers. The mean value of polymorphic bands was 12/44 per primer bond. The Analysis of cluster base on Jacquard correlation coefficient was performed by using UPGMA algorithm on three populations of yarrow which contain 30 plant samples. Individuals in three populations were completely separated in clusters which revealed genetic distance between populations. In addition, the chemical compounds and the amount of essential oils, three Yarrow masses have been investigated at this study. The obtained results indicate that there were a high differences between all studied masses in their essential oil compounds. The compound of δ-2-Carene with 33/79 percent was the most observed compound in the studied Yarrow masses in Hormozgan province. In general, the results of this experiment showed that there was a high genetic and phytochemical diversity in Achillea (Yarrow) populations in terms of used molecular marker and their essential oil compounds.

Ethylene is involved in many developmental and processes including plant senescence. Senescence is the final step of plant development resulting in death of plants. 1-aminocyclopropane 1-carboxylic acid) ACC) is produced in the last step of the ethylene biosynthesis. The Morphological characteristics of treated plants by ACC induce a phenotype called triple response including root and hypocotyl shortness and thickness. The occurrence of these symptoms indicates that plant system sense ethylene and its biosynthesis is activate. In this project, we examined the response of the wild type seedlings Ler-0, Col-0 and several mutants including old-3, old-9, old-14, etr1-3 and ko-5 to various concentration of ACC in Arabidopsis thaliana following evaluation of triple response characteristics. OLD genes in Arabidopsis are known as senescence involved genes. According to the obtained results, it shown that with increasing ACC concentrations, the triple response has been detected in most mutants, while in mutant etr1-3 none of those responses were observed meaning that etr1-3 is not able to sense and signal ethylene. These results suggest that change in OLD9, OLD3 and OLD14 function doesnt cause any significant impact on ethylene biosynthesis and signaling, while change in gene activity ETR in Arabidopsis led to the loss of the triple response in etr-3 plants. Thus, the genes controlling ethylene biosynthesis is different from genes regulating plant senescence.

The identification of genomic loci involved in control of quantitative traits receives growing attention in plant molecular breeding. The present study was carried out to evaluate the genetic variability among 48 rice genotypes and determine the genomic regions associated with ten grain related important traits. A total number of 63 alleles were detected by 18 selected SSR markers from different chromosomes with an average of 3.5 alleles per marker. A model-based Bayesian approach subdivided 48 evaluated rice genotypes into three major subgroups with the consideration of the highest value of ΔK. The mean r2 value for all loci pairs on the same chromosome was 0.053. A total of 38 significant marker-trait associations were identified (P