MODERN GENETICS JOURNAL (MGJ)
Year:2018 | Volume:13 | Issue:3|Papers Count:12

Wild relatives of wheat have served as an ideal gene pool for improving drought tolerance in wheat. The objective of this study was to investigate the expression patterns of several antioxidant genes comprising MnSOD, APX and GPX in the different cultivated and wild wheat species under control (90% field capacity) and drought stress (25% field capacity) conditions. For this purpose, a factorial experiment based on randomized complete block design with four replications (two biological and two technical replications) was conducted to compare five species of Aegilops and two species of Triticum along with two bread wheat check cultivars SIRVAN (as resistant to drought) and DARYA (as sensitive to drought) in greenhouse. The analysis of variance for the relative gene expression values showed significant effects for the drought stress, species and their interaction. Drought stress increased expression of MnSOD, APX and GPX by 9. 55, 12. 64 and 10. 18-fold more than the control condition, respectively. Moreover, the results obtained by species comparison indicated a differential expression pattern of these genes among species. As a remarkable result Ae. tauschii, Ae. speltoides and Ae. cylindrica species showed higher expression than other species as well as the tolerant control variety when subjected to a high level of drought stress. Therefore, further studies on these species to determine the mechanisms associated with tolerance to drought stress are recommended.

Phosphorus (P) is one of three essential macronutrients required for plants which is absorbed as phosphate ion (Pi) from the soil solution and plays an important role in plants growth and development. To cope with low Pi concentrations in soil, plants have a wide range of morphological and physiological adaptive responses including acid phosphatase secretion. In this study, the full-length cDNA encoding sequence of AtPAP18 was isolated from a cDNA pool of Arabidopsis and cloned in a plant expression vector to produce a series of overexpressed lines. Also, a homozygous knocked-out mutant was identified for disruption in AtPAP18 locus too. Our results indicated that the overexpression of AtPAP18 in Arabidopsis plants led to significant increases in total P contents and biomass production for plants grown in Pi-fed and starved conditions. Faster germination, remarkable decrease in fresh and dry weight of and the highest root– shoot ratio in the starved plants was the obvious symptoms of the knocked out plants in comparison to wild type or overexpressed ones. The results indicated that overexpression of the AtPAP18 gene offers an effective way to increase the utilization of soil insoluble Pi and reduce the consumption of the relevant chemical fertilizer.

performed using specific primers designed from conserved sequences of the gene in NCBI database. The sequence analysis (609 bp) revealed that the detected PAL gene is similar to those previously sequenced in the NCBI database. Methyl jasmonate is a cyklopentany compound of linolenic acid derivatives which can be produced through the octadecanoid pathway. There are evidences that methyl jasmonate as a signaling molecule interference in some signaling pathways that induces certain enzymes catalyze biosynthetic reactions for the formation of the defensive reaction and leading to the induction of immune responses. In the current study, gene expression of PAL gene was evaluated by applying of 50 and 100μ m MeJA, at intervals of 24, 48 and 72 hours. Results showed that expression of PAL gene significantly increased in response to MeJA after 24h. The gene expression of PAL was significantly higher after 24h treating samples with 100μ m MeJA compared to the control. The results of this study suggest that metyl jasmonate is an efficient abiotic elicitor which affect expression of PAL invovled in polyphenol compounds in Burdock

Different parts of the greater celandine herb contain important alkaloids such as chelodonin, chloritin, sanguinarine, and berberine. Sanguinarine is a four-member benzofenanthridine that is widely found in Papaveraceae, Fumariaceae and Rutaceae. This biologically active alkaloid, singuainarin, has a wide range of potentially useful pharmacological properties, such as anti-microbial, anti-inflammatory, and anti-tumor. The first step in biosynthesis pathway of sanguinarine alkaloid requires the transformation of S-reticulin to S-skolorine, which catalyzes by berberine beridge enzyme encoded by the BBE gene. In order to prepare plant materials for gene isolation, and the expression of BBE gene in four drought levels including severe, moderate, weak stress and non stress (40, 55, 70 and 100% field capacity, respectively) in three organs, root, stem and leaf, an factorial experiment was carried based on completely randomized design with three replications. RNA was extracted from root, stem and leaf to isolate the cDNA encoding BBE enzyme and study the gene expression. The cDNA encoding BBE enzyme with approximate length of 1500 bp was isolated from root and successfully integrated into PTG19-T plasmid and cloned at E. coli. The sequencing results showed that the isolated gene with a length of 1441 bp could translate to a peptide chain with 483 amino acids. The predicted BBE peptide chain had NX(S/T) motif as glycosylation sites, the flavin binding domain for the binding of flavinated histidine, SGGH motif, and the Glu sequence which plays an important catalytic role in the formation of berberine bridge in flavoprotein enzymes. Based on the mean comparison results, the highest and lowest expressions of this gene were obtained on root under weak drought stress (FC 70%) and on leaf and shoot under non-stress condition (100% FC), respectively. In general, it can be concluded that the weak drought stress can increase the BBE gene expression, and possibly this could result in higher production of sanguinarine in celandine.

miRNAs are a class of non-coding and small RNAs (~ 21 nucleotides) performs a key function in plant growth and physiology by regulating gene expression in post-transcriptional level. Since there has not been a comprehensive study on identification of the miRNAs of safflower (Carthamus tinctorius L) using in silico method, in current study, 124 potential miRNAs belonging to 26 conserved families were identified and two miRNAs were validated using qRT-PCR technique. The 29 miRNA families were significantly different in size. Safflower pre-miRNAs greatly varied from 57 to 317 nt in length with an average of 94. 56 ± 38. 1 nt. Another result of this study was the success in determining miR169, miR395 and miR397 clusters in the safflower genome. In the present study, the family members of miRNAs including miR393, miR477, miR530, miR6111, miR6113, and miR6114were recognized which have not previously been reported. A total of 84 potential target genes were predicted for the identified safflower miRNAs including transcription factors, proteins involved in DNA replication, and metabolic enzymes. The results of this study showed the existence of conserved miRNAs in safflower and may be important role in response to environmental stress.

Plants are using various mechanisms at the molecular, biochemical and physiological levels for resistance to cold stress. These responses are controlled via stress phytohormones. One of the main hormones is jasmonic acid that plays main roles in various stress, however, there are few studies of the effects of the hormones on cold stress. Its signaling pathway in response to low temperature has remained unknown. In this study, a weighted gene co-expression network was utilized to determine the effect of jasmonic acid in response to cold by using microarray data at Arabidopsis. The 15 gene groups were found that each one controls a special process. Photosynthesis and carbohydrate catabolic and metabolic processes are the most important biological processes in response to the two stimuli. Gene co-expression network displays that transcription factors play main roles in the processes. According to results, two transcription factors ERF13 and ORA47 candidate for relationship between jasmonic acid and cold tolerance and possibly intermediate between CBF1 and CBF2 transcription factors and regulatory proteins in the jasmonic acid signal transduction pathway, tify family. Three transcription factors (HY5, bHLH15 and PIF3) also cooperate in the signaling pathway to respond to low temperature in plants.

Given the importance of research related to abiotic stress, this study is to identify markers significantly associated with traits associated with drought tolerance in rice was done. In this study 36 microsatellite markers (SSR) and 59 rice genotypes were used in both normal and drought conditions. A total of 189 alleles in 36 microsatellite markers with an average of 25. 5 alleles per locus were observed. RM5647 represents the highest number of alleles (12) and RM462 and 6022 RM has the lowest number of alleles (2). Average polymorphic information content was estimated (0. 58) that RM5647(0. 81) and RM6022 (0. 32) had highest and lowest PIC, respectively. In this study, 21 agronomic traits along with eight Stress Tolerance Index (SSI, STI, MP, GMP, HM and STS) was measured. Association analysis using matrix structure of the population and statistical models GLM and MLM was performed. 11 and 22 informative markers were determined in normal and drought condition using MLM model respectively. Under normal conditions, RM5780 had the highest coefficient of determination and explained 29. 92% variation of grain yield. In drought condition, RM519 was related to days to heading and explained 39. 69% of variation. 6 significant markers identified for eight indicators evaluated. RM441 had the highest percentage of phenotypic variation (26. 11%) of TOL variation. According to the results, microsatellite markers detected in the present study after specification and being confirmed are suitable for using marker-assisted selection.

Thymus vulgaris is one of the dark Lamiaceae plants in different parts of the Mediterranean and some parts of Asia, and today it is cultivated in different parts of the world, including Iran. The medicinal effects of this plant are related to various compounds, including thymol and carvacrol. This research was conducted in a randomized complete block design with three replications. Treatments were carried out in 4 levels of salinity (control, 50, 100 and 150 mM. ). Physiological Aspects and phytochemical yield were evaluated. Expression of genes was evaluated by qRT PCR method and essential oil was analysis by HPLC method. The results showed that salinity stress had a significant effect (p≤ 0. 05) on the expression of the studied genes. The highest expression of TvTPS1 (TvTPS5) genes was observed in 100mM treatment and the highest TvDXR expression was observed in 50mM NaCl treatment. The highest levels of thymol and carvacrol were observed in 100 mM NaCl. The 100 mM NaCl concentration increased thymol and carvacrol content by affecting the up and down stream genes of the MEP and thymol biosynthesis pathways through signaling processes.

In the present study the potential consideration of calf birth weight (BW) and gestation length (GL) as correlated traits for improving genetic evaluation of calving difficulty (CD) in Iranian Holsteins at first calving was studied applying data collected from 2002 to 2013 in 131 herds by Animal Breeding and Production Improvement center of Iran. The influences of direct and maternal additive genetic effects on each trait were tested and the most appropriate model for each trait determined. Considering the most appropriate model for each trait, predictive abilities of four genetic evaluation models of CD including univariate model of CD, bivariate model of CD and BW, bivariate model of CD and GL and trivariate model of CD, BW and GL were compared applying mean of squares and correlation between observed and predicted values. The obtained results revealed that the model included direct additive genetic and maternal additive genetic effects as random effects, without considering covariance between them, was the most appropriate model for estimating variance components of the considered calving traits. Comparisons of the models revealed that model included CD and BW had better predictive ability than univariate model included CD and the bivariate included CD and GL in terms of lower mean square of error and higher Pearson correlation between observed and predicted values of CD. There was no difference between bivariate model (CD-BW) and multivariate model (CD-BW-GL) in terms of predictive ability. Therefore, BW can be considered as a suitable correlated trait for genetic evaluation of CD at first calving in Iranian Holsteins.

The genus Fritillaria is recognized as a medicinal and ornamental plant with various pharmaceutical active ingredients, which have been used in traditional medicine. Isosteroidal alkaloids are the major bioactive components in Fritillaria imperialis which include antihypertensive, anticholinergic, antitumour, antiasthmatic and antitussive activities. SQS is a membrane-bound enzyme that plays an important regulatory role in the sterol biosynthetic pathway. In this study, we identified SQS with a key role in the biosynthesis of the Isosteroidal alkaloids by selecting Crown Imperia transcriptome profile. There was high sequence similarity with other flowering plant genes, such as Fritillaria thunbergii, Phoenix dactylifera, Fritillaria unibracteata in the NCBI database using Blastx. The result of alignment with clustal w showed that these sequences were been matched in the conserved region. The results of promoter analysis have shown that it includes responsive elements to light, drought, jasmonic acid, auxin, core promoter element, enhancer and the other elements. The presence of these regulatory elements plays a key role in regulating gene expression in different developmental stages responding to environmental and biosynthesis of secondary metabolites. Finally, expression patterns of SQS in different tissue (leaf, bulb, anther, ovary, sepal, petal and fruit) were assessed in three developmental stages including stem elongation stage, flower development and seed head stage based by qPCR analysis. It suggests that the important role of FiSQS in F. imperialis secondary metabolites biosynthetic. Statistical analysis showed a significant difference for SQS expression level in different tissue and during three developmental stages in, F. imperialis.

Induced resistance (IR), activated either by a prior pathogen infection (biological induced resistance) or by treatment with a chemical. Induced resistance is thought to play an important role in the preservation of plants in nature. Although several types of IR have been identified, the one that has been studied most extensively is systemic acquired resistance (SAR). Systemic acquired resistance is an inducible defense mechanism that plays an important role in disease resistance in plants. It has been found that agrochemical components cause SAR in plants. One of the effective agrochemicals is benzothiadiazole (BTH). The exogenous application of BTH to leaves augments the sensitivity of cells to respond to elicitation. BTH has been developed as a novel disease control compound that is translocated throughout the plant where it acts by inducing an inherent disease resistance response. In order to investigate the mechanisms of BTH biochemical activity and its induced genes, BTH-related EST sequences were mined from NCBI site. Clustering and assembling about 370 rice EST sequences were formed after treatment with BTH resulted in 33 contig and 234 singltone, and then functional groups were determined and compared with the two libraries of common genes. The results of this study indicated that after application of BTH on rice, kinase, LHCB and OEEP proteins as well as the carbonic anhydrase and Ribulose enzymes are expressed. This study is the first report that effect of BTH on plant photosynthesisc. In this study novel candidate genes were identified which may have a possible involvement in plant defense mechanism. This kind of bioinformatics studies may be useful in molecular breeding programs in rice for development of diseases tolerance varieties.

The role of high molecular weight subunits of glutenin in determining the bread-making quality of bread wheat (Triticum aestivum L. ) has caused their evaluation in storage proteins to be converted one of the most important goals for the breeders. The chromosomal arm 1RS of rye (Secale cereale L. ) carries genes for resistance to pests and pathogens that leads to the stability of wheat grain yield, however the 1RS arm has a negative effect on bread-making quality. In the current study, the quality scores were determined in 14 Iranian wheat cultivars, containing the 1BL. 1RS wheat-rye chromosome translocation, using specific STS markers, then quality scores were adjusted due to the presence of 1BL. 1RS translocation. Adjusted quality scores of cultivars were between five to seven. Moghan 3, Arta and B. C. Roshan (Winter) with the adjusted quality score of seven, had the highest score, and Mahdavi, Dez, MV17, Shirodi, Vee/Nac, Star and Rasad with the adjusted quality score of five, had the lowest score. Iranian commercial cultivar of wheat, carrying the 1BL. 1RS translocation, using desirable glutenin subunits is able to partly compensate the negative effects of 1BL. 1RS translocation on the flour quality and has a medum quality score. In breeding programs, it is suggested that the possible presence of rye chromosome arm 1RS in wheat genetic background and its negative effects on the flour quality should be considered because is preventing the achievement of false positive results by breeders.