Effect of drought stress on the expression pattern of genes involved in ABA biosynthesis in Desi-type chickpea (Cicer arietinum L.).

BACKGROUND: The behavior of Abscisic acid (ABA) as a stress phytohormone may be involved in mechanisms leading to tolerance and survival in adverse environmental conditions such as drought stress. METHODS: Here, we evaluated ABA-mediated responses at physio-biochemical and molecular levels in drought-stressed seedlings of two different Desi-type chickpea genotypes (10 as a tolerant genotype and 247 as a sensitive one). RESULTS: Under drought stress, two chickpea genotypes showed a decrease in their relative water content (RWC), and the intense decrease was related to the sensitive genotype (73.9%) in severe stress. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) concomitant with the severity of stress increased in genotypes and the higher increase was in the sensitive genotype (5.8-fold and 3.43-fold, respectively). In the tolerant genotype, the enhanced accumulation of total phenolic content (1.75-fold) and radical scavenging action, based on 1,1-diphenyl-2-picrylhydrazyl test (DPPH), (1.69-fold) were simultaneous with ABA accumulation (1.53-fold). In the tolerant genotype, transcriptional analysis presented upregulation of Zeaxanthin epoxidase (ZEP) (1.35-fold), 9-cis-epoxycarotenoid dioxygenase (NCED) (5.16-fold), and Abscisic aldehyde oxidase (AAO) (1.52-fold compared to control conditions) genes in severe stress in comparison with mild stress. The sensitive genotype had a declining trend in total chlorophyll (up to 70%) and carotenoid contents (36%). The main conclusion to be drawn from this investigation is that ABA with its regulatory effects can affect drought tolerance mechanisms to alleviate adverse effects of unsatisfactory environmental conditions. CONCLUSIONS: In this paper, we tried to indicate that drought stress induces overexpression of genes triggering ABA-mediated drought responses simultaneously in two genotypes while more increment expression was related to the tolerant genotype. At first thought, it seems that the tolerant genotype compared to the sensitive genotype has a genetically inherent ability to cope with and drop adverse effects of drought stress through over-accumulation of ABA as drought.

Seed osmopriming with Ca2+ and K+ improves salt tolerance in quinoa seeds and seedlings by amplifying antioxidant defense and ameliorating the osmotic adjustment process.

Salinity restricts seed germination and seedling growth through induction of osmotic and oxidative stresses. Therefore, this study aimed to enhance salinity tolerance in quinoa seed by pre-optimized osmo-priming treatments of CaCl2 (10 mM, 10 °C, 10 h) and KNO3 (150 mM, 5 °C, 24 h). The results showed that these treatments developed the cellular defense mechanisms in seeds as 'priming memory' that could improve the physiological and biochemical responses to salinity in post-priming stages. The germination capacity and seedling growth decreased with increasing salinity that was accompanied with a higher content of MDA and H2O2. However, the improvement of primed seed vigor against high salinity was explained by increasing the biological defense mechanisms including antioxidant enzymes (CAT, APX, SOD, GPX and PPO) and antioxidant metabolites (DPPH antioxidant activity, phenolics, flavonoids, ascorbic acid), particularly in presence of salt stress. In addition, Ca2+ and K+ priming acquired salinity tolerance in post-priming stages through a significant increase in the accumulation of proline, glycine-betaine, soluble carbohydrate. Improvement in homeostasis of K+/Na+ ratio by promoting K+ maintenance and Na+ exclusion was also found in post-priming stages. These observations may be utilized as effective methods in improving salinity tolerance of quinoa seed germination in saline agriculture by improving the antioxidant system, osmolyte accumulation and mineral nutrient homeostasis.

Evaluation of physiological and biochemical responses of pistachio plants (Pistacia vera L.) exposed to pesticides.

Pesticides may manipulate plant physiology as non-target organisms. In this study, we examined biochemical responses of pistachio plants (Pistacia vera L.) to imidacloprid and phosalone as common pesticides used to control pistachio psyllids. Enzymatic characterization in treated plants with pesticides showed greater specific activities of superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, phenylalanine ammonia-lyase, glutathione reductase, and glutathione S-transferase compared with untreated plants during 14 days after treatment. Further experiments displayed elevated levels of total phenols and total proteins coupled with significant increases in proline and total soluble carbohydrate contents in treated plants in comparison to untreated plants. Moreover, pesticide treatment leads to a significant decrease in polyphenol oxidase activity. Nevertheless, no significant changes in contents of hydrogen peroxide, malondialdehyde, total chlorophyll, and electrolyte leakage index were obtained in treated plants. Pesticides' impacts on host plant physiology resulted in similar responses between two pesticides with differences in peak days. Overall, the findings of this study provide an insight into the side effects of phosalone and imidacloprid, chemicals with no specific target site in plants, on the physiology and biochemistry of pistachio plants at recommended rates.

Diagnostic value of cytology in oral ulcer and comparison with histopathology and direct immunofluorescence.

Rapid diagnosis of pemphigus vulgaris (PV) is an important task in patient's prognosis and treatment. Although PV is routinely diagnosed through investigation of pathology specimens and direct immunofluorescence assays, Tzanck smear can be used as rapid, inexpensive, and easily used test to confirm its clinical diagnosis. This study aimed to determine the diagnostic value of Tzanck smear in erosive oral lesions of PV and also determine its sensitivity and specificity for diagnostic purposes. A total of 68 patients with erosive/ulcerated oral lesions were included in this study and divided into PV (case group) vs other causes of erosive oral lesions (control group). From all participants, two Tzanck smears were prepared for both Giemsa and hematoxylin-eosin (H&E) staining. For definite diagnosis, histopathology and direct immunofluorescence evaluations were performed based on clinical findings. The sensitivity of acantholytic cells in Tzanck smear of erosive oral lesions of PV cases was 80.5% (for both Giemsa and H&E staining), whereas specificity values of Giemsa and H&E staining were 84.6% and 96.3%, respectively. Based on our findings, the Tzanck smear of erosive oral lesions is a simple, quick, and inexpensive test for screening and primary diagnosis of PV.

Evaluation of health-related quality of life after total hip arthroplasty: a case-control study in the Iranian population.

BACKGROUND: As the total hip arthroplasty (THA) mainly aims to improve the quality of life of the patients, study of health-related quality of life (HRQoL) after THA has attracted much attention. Yet, the results considerably vary between studies. Here, we evaluate the HRQoL of the patient after THA, for the first time in the Iranian population. METHODS: In a case-control study, HRQoL was assessed in 217 patients after THA and compared with a matched reference population. The 36-item short-form health survey (SF-36) was used for the evaluation of HRQoL. A multiple linear regression model was used to investigate the influence of sociodemographic and clinical characteristics of the patients on the HRQOL. RESULTS: The mean follow-up of the patients was 27 ± 18 months. The mean total SF-36 score was 41.4 ± 22.2 in the case and 67.3 ± 26.6 in the control group (p = 0.001). The mean physical component score, but not the mental component score, was significantly lower in the patient group (p = 0.001). Except for the vitality and emotional role, all other SF-36 subscales were significantly lower in the case group. Male sex (B = 4.52, p = 0.023), number of comorbidities (B = - 4.82, p = 0.011), body mass index (B = - 1.18, p = 0.044), number of post-operative complications (B = - 6.57, p = 0.001), and adherence to physiotherapy protocol (B = 2.09, p = 0.014) were associated with HRQoL after THA. CONCLUSION: Although THA is considered as one of the most successful orthopedic practices, it is associated with remarkable reduced HRQoL in Iranian population when compared with the reference population. A variety of patients-associated factors influence the HRQoL after THA.

Antixenosis and antibiosis response of common bean (Phaseolus vulgaris) to two-spotted spider mite (Tetranychus urticae).

The two-spotted spider mite, Tetranychus uticae Koch (Acari: Tetranychidae), is globally one of the most devastating pests that feed on numerous crops, including common bean (Phaseolus vulgaris L.). This study was aimed to evaluate the effects of genotype and morphological attributes of common bean on T. uticae. Forty common bean accessions were used to investigate antixenosis and antibiosis through assessing mite feeding preference and reproduction under laboratory conditions. Three resistant (i.e., 56, 63, 238) and two susceptible (i.e., 182, 236) accessions, along with cultivars Naz (resistant) and Akhtar (susceptible), were used in a life-table study. Both antixenosis and antibiosis mechanism were observed in all of the accessions, albeit a negative correlation occurred. Significant differences were observed for all traits of T. urticae: developmental time of immature stages, reproduction, adult longevity and life-table parameters. Based on the intrinsic rate of increase, the accessions 56, 63, 182, 238, and cv. Naz impose high antibiotic effects on T. urticae. Although significant variation existed among accessions for morphological factors, only glandular trichomes correlated with mite fecundity and feeding preference.

Genetic diversity of bread wheat genotypes in Iran for some nutritional value and baking quality traits.

Genetic variation among 78 irrigated bread wheat genotypes was studied for their nutritional value and baking quality traits as well as some agronomic traits. The experiment was conducted in a randomized complete block design with three replicates under normal and terminal drought stress conditions in Kermanshah, Iran during 2012-2013 cropping season. The results of combined ANOVA indicated highly significant genotypic differences for all traits. All studied traits except grain yield, hectoliter weight and grain fiber content were significantly affected by genotype × environment interaction. Drought stress reduced grain yield, thousand kernel weight, gluten index, grain starch content and hectoliter weight and slightly promoted grain protein and fiber contents, falling number, total gluten and ratio of wet gluten to grain protein content. Grain yield by 31.66% and falling number by 9.20% attained the highest decrease and increase due to drought stress. There were negative and significant correlations among grain yield with grain protein and fiber contents under both conditions. Results of cluster analysis showed that newer genotypes had more grain yield and gluten index than older ones, but instead, they had the lower grain protein and fiber contents. It is thought that wheat breeders have bred cultivars with high grain yield, low protein content, and improved bread-making attributes during last seven decades. While older genotypes indicated significantly higher protein contents, and some of them had higher gluten index. We concluded from this study that it is imperative for breeders to pay more attention to improve qualitative traits coordinated to grain yield.

Comparison of old and new wheat cultivars in Iran by measuring germination related traits, osmotic tolerance and ISSR diversity.

A primary concern of modern plant breeding is that genetic diversity has decreased during the past century. This study set out to explore changes in genetic variation during 84 years of breeding by investigating the germination-related traits, inter-simple sequence repeat (ISSR) fingerprinting and osmotic stress tolerance of 30 Iranian wheat (Triticum aestivum L.) cultivars. Seeds were planted under control and osmotic stress (-2, -4 and -6 bar) in three replications. The ISSR experiment was carried out using 32 different primers. Genotypes were divided into two groups (old and new) each containing 15 members. The results of ANOVA showed that highly significant differences existed among genotypes and among growth conditions. The results showed that during breeding in some traits such as coleoptile length and seedling vigor index, a significant decrease has been occurred. New cultivars had a mean coleoptile length of 33 mm, shorter than that of old cultivars (42 mm) under osmotic stress of -6 bar. Genetic variance of root length, shoot length and seedling vigor index for old cultivars were 1.59, 1.93 and 45,763, respectively, significantly higher than those for new cultivars (0.55, 1.08 and 27,996, respectively). This difference was also verified by ISSR results as the polymorphism information content was 0.28 in old cultivars, higher than that of new cultivars (0.26). These results prove this claim that during breeding, genetic diversity has decreased for many germination-related traits and breeders are better to pay more attention to genetic diversity.

Membrane fatty acid compositions and cold-induced responses in tetraploid and hexaploid wheats.

Plant cells often increase cold tolerance by reprogramming their genes expression which results in adjusted metabolic alternations, a process enhanced under cold acclimation. In present study, we assessed the changes of membrane fatty acid compositions along with physio-biochemical indices like H2O2 and malondialdehyde (MDA) contents and lipoxygenase (LOX) activity during cold stress (CS) phases in acclimated and non-acclimated durum (SRN and Gerdish) and bread (Norstar) wheat genotypes. During thermal treatments, MDA was an end product of lipid peroxidation via oxidative stress (H2O2 content) rather than LOX activity. LOX activity plays a double role in mechanism of cold tolerance in wheat, particularly at severe stress. With increase in severity of CS especially in non-acclimated plants, LOX activity decreased along with an increase in MDA and other responses helped increase or maintaine unsaturated fatty acids (FAs) whereas in acclimated plants (moderate CS), increasing of LOX activity along with a decrease in MDA indicates probably its role in secondary metabolites like jasmonic acid signaling pathway. Significant increase of total FAs and particularly unsaturated FAs showed distinct cell endeavor to protect against CS in Norstar and Gerdish compared to SRN genotype. Results showed that an increase in double bond index and LOX activity and low MDA under CS could be reasons for plant cold tolerance.

Global insights into intermediate metabolites: Signaling, metabolic divergence and stress response modulation in plants.

Climate change-induced environmental stresses pose significant challenges to plant survival and agricultural productivity. In response, many plants undergo genetic reprogramming, resulting in profound alterations in metabolic pathways and the production of diverse secondary metabolites. As a critical molecular junction, intermediate metabolites by targeted intensification or suppression of subpathways channel cell resources into a multifaceted array of functions such as cell signals, photosynthesis, energy metabolism, ROS homeostasis, producing defensive and protective molecules, epigenetic regulation and stress memory, phytohormones biosynthesis and cell wall architecture under stress conditions. Unlike the well-established functions of end products, intermediate metabolites are context-dependent and produce enigmatic alternatives during stress. As key components of signal transduction pathways, intermediate metabolites with relay and integration of stress signals ensure responses to stress combinations. Investigating efficient metabolic network pathways and their role in regulating unpredictable paths from upstream to downstream levels can unlock their full potential to shape the future of agriculture and ensure global food security. Here, we summarized the activity of some intermediate metabolites, from the perception step to tolerance responses to stress factors.

Physio-biochemical and DNA methylation analysis of the defense response network of wheat to drought stress.

In the present work, physio-biochemical and DNA methylation analysis were conducted in wheat (Triticum aestivum L.) cultivars "Bolani" (drought-tolerant) and "Sistan" (drought-sensitive) during drought treatments: well-watered (at 90% field capacity (FC)), mild stress (at 50% FC, and severe stress (at 25% FC). During severe stress, O2•- and H2O2 content in cultivar Sistan showed significant increase (by 1.3 and 2.5-fold, respectively) relative to cultivar Bolani. In Bolani, the increased levels of radical scavenging activity (by 32%), glycine betaine (GB) (by 11.44%), proline (4-fold), abscisic acid (by 63.76%), and more stability of relative water content (RWC) (2-fold) were observed against drought-induced oxidative stress. Methylation level significantly decreased from 70.26% to 60.64% in Bolani and from 69.06% to 59.85% in Sistan during stress, and higher decreased tendency was related to CG and CHG in Bolani but CG in Sistan under severe stress. Methylation patterns showed that the highest polymorphism in Bolani was mainly as CG. As the intensity of stress increased, the enhanced physio-biochemical responses of Bolani cultivar were accompanied by a more decrease in the number of unchanged bands. According to heat map analysis, the highest difference (84.38%) in methylation patterns was observed between control and severe stress. Multivariate analysis using principal component analysis (PCA) showed a cultivar-specific methylation during stress and that methylation changes between cultivars are much higher than that of within a cultivar. Higher methylation to demethylation in Bolani (30.06 vs. 22.12%) compared to that of cultivar Sistan (23.21 vs. 30.15%) indicated more demethylation did not induce tolerance responses in Sistan. Sequencing differentially methylated fragments along with qRT-PCR analysis showed the efficient role of various DNA fragments, including demethylated fragments such as phosphoenol pyruvate carboxylase (PEPC), beta-glucosidase (BGlu), glycosyltransferase (GT), glutathione S-transferase (GST) and lysine demethylase (LSD) genes and methylated fragments like ubiquitin E2 enzyme genes in the development of drought tolerance. These results suggested the specific roles of DNA methylation in development of drought tolerance in wheat landrace.

Change in membrane fatty acid compositions and cold-induced responses in chickpea.

Plant cells often increase cold tolerance by reprogramming their genes expression which results in adjusted metabolic alternations, a process enhanced under cold acclimation (CA) phase. In present study, we assessed the changes of membrane fatty acid compositions and defense machine (like antioxidative enzymes) along with damage indexes like electrolyte leakage index (ELI) and malondialdehyde (MDA) during CA, cold stress (CS) and recovery (R) phases in chickpea (Cicer arietinum L.). Results showed an increase in unsaturated fatty acids ratio compare to saturated ones which is a sign of cold tolerance especially after CA phase. Antioxidant enzymes had an important role during CA and R phases while CS affected their activity which can be a sign for associating other metabolites or enzymes activities to create cold tolerance in plants. To investigation of enzymes assay under experimental treatments, the expression pattern of some enzymes including superoxide dismutase (sod), catalase (cat) and lipoxygenase (lox) was studied using quantitative real time PCR. LOX activity has shown a bilateral behavior: a positive relation with membrane damage index in CA and an interesting link with double bond index (DBI) in CS indicating probably its role in secondary metabolites like jasmonic acid signaling pathway. It was suggested that increased DBI and low LOX activity under CS could be a reason for plant cold tolerance.

Factors predicting early deterioration in mild brain trauma: a prospective study.

PRIMARY OBJECTIVE: To evaluate risk factors for clinical deterioration in mild traumatic brain injury. RESEARCH DESIGN: Prospective cross-sectional. METHODS AND PROCEDURES: This study evaluated 203 patients with mild traumatic brain injury. A brain computed tomography scan was performed in all patients and they were observed for 6-48 hours. MAIN OUTCOMES AND RESULTS: Among these patients, 2.5% had cerebral contusions and the most common sites for contusions were frontal lobes; 94% of patients had no hematoma in the initial scan, while 3% had subgaleal haematoma, 1.5% had subdural haematoma, 1% showed subarachnoid haemorrhage, 0.5% intracerebral haemorrhage and 0.5% epidural haemorrhage. GCS was 15 in 96.6% and 13-14 in 3.4%. GCS deteriorated in three (1.5%). Presence of coagulopathy, anticoagulant drug use, GCS of 13-14 and increased age predicted further deterioration. Among CT findings, those with midline shift, cerebral contusion and diffuse cerebral oedema deteriorated more. Among different haematoma types, only SDH predicted a worse outcome. CONCLUSIONS: Although deterioration rarely occurs in patients with mild brain injury, those with coagulopathy, anticoagulant drug use, GCS of 13-14, increased age, midline shift, cerebral contusions, diffuse cerebral oedema and SDH were more prone to deterioration.

Low-temperature acclimation related with developmental regulations of polyamines and ethylene metabolism in wheat recombinant inbred lines.

Winter survival is determined by complicated developmental regulations enabling wheat to adjust their transcriptome and metabolome to develop low temperature (LT) tolerance. The aim of the study was to clarify the metabolic responses developmentally regulated in six F6 recombinant inbred lines from a cross between Pishtaz (spring parent) and Mironovskaya 808 (winter parent). Spring genotypes, including pishtaz, RILs 4006 and 4014 showed lower LT tolerance, PAs (except the spermin), GABA and proline contents and DPPH• scavenging capacity. In these genotypes, genes and enzymes involved in the pathways of PAs and GABA degradation and ethylene biosynthesis were more active than other genotypes. RILs 4012 and 4016 with short vernalization displayed higher tolerance and lower H2O2 content compared to Pishtaz. Strong vernalization requirements in winter and facultative genotypes (Mironovskaya 808 parent and RILs 4003 and 4005) results in up-regulation of the metabolites and genes involved in PAs and GABA biosynthesis pathways (particularly when vernalization fulfillment occurred) to establish high tolerance as compared to genotypes without vernalization requirement. LT tolerance in all genotypes significantly decreased after vernalization fulfillment in February. Results indicated that LT tolerance was partly validated from developmental regulation of PAs, GABA, and ethylene metabolism during venalization and LT acclimation.

Cold stress-induced changes in metabolism of carbonyl compounds and membrane fatty acid composition in chickpea.

In this study, changes in membrane fatty acid (FA) composition and damage indices contents as well as the transcript patterns of carbonyl-detoxifying genes were evaluated in two chickpea (Cicer arietinum L.) genotypes, cold-tolerant Sel96th11439 and cold-sensitive ILC533 under cold stress (CS; 4 °C). During CS, H2O2 and malondialdehyde (MDA) contents increased (by 47% and 57%, respectively) in the sensitive genotype, while these contents remained unchanged in the tolerant genotype. In tolerant plants, higher content of linoleic, linolenic, unsaturated FAs (UFAs), total FAs and double bond index (DBI) (by 23, 21, 19, 17 and 9%, respectively) was observed at 6 days after stress (DAS) compared to sensitive plants, which, along with alterations of the damage indices, indicate their enhanced tolerance to CS. Compared with the sensitive genotype, less lipoxygenase (LOX) activity (by 59%) in the tolerant genotype was accompanied by decreased MDA and increased levels of UFAs and DBI during CS, particularly at 6 DAS. Upregulation of aldehyde dehydrogenase and aldo-keto reductase genes (by 9- and 10-fold, respectively) at 1 DAS, along with the enhanced transcript levels of aldehyde reductase and 2-alkenal reductase (by 3- and 14.7-fold, respectively) at 6 DAS were accompanied by increased UFAs and reduced MDA contents in the tolerant genotype. Overall, the results suggest that cold tolerance in chickpea was partly associated with regulation of membrane FA compositions and the potential metabolic networks involved in synthesis and degradation of carbonyl compounds.

Salicylic Acid Induced Resistance in Drought-Stressed Pistachio Seedlings Influences Physiological Performance of Agonoscena pistaciae (Hemiptera: Aphalaridae).

Induced host plant resistance is a potential approach to insect and disease management. Salicylic acid (SA) acts as a signal molecule to induce resistance in plants against sap-sucking insects. The effects of salicylic acid-induced resistance against common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer, were investigated in well-watered and drought-stressed pistachio, Pistacia vera L. cv. Akbari, seedlings. Agonoscena pistaciae exhibited a significant preference for plants treated with SA as compared with untreated controls or those subjected to drought stress. Plants subjected to both drought stress and SA treatment were equivalently colonized as compared with control plants but were more attractive than those subjected to drought stress alone. Psyllid mortality increased on plants subjected to simultaneous drought stress and SA treatment as compared with controls. Salicylic acid treatment mediated production of defensive enzymes in plants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), guaiacol peroxidase (GPX) and polyphenol oxidase (PPO), as well as that of other metabolites such as phenol, malondialdehyde (MDA), H2O2, free amino acids, and pigments via phenylpropanoid pathways under conditions of drought. Despite increases in activity of detoxification (glutathione S transferase, carboxylesterase) and antioxidative (SOD, CAT, APX, phenoloxidase, GPX) enzymes in psyllids, reduced survival of A. pistaciae on drought stressed and SA-treated plants was likely caused by excessive H2O2 and high phenolic content in treated plants. Based on our results, we postulate that salicylic acid-induced defense against A. pistaciae under drought conditions could be manipulated to enhance antibiosis against this key pest in pistachio orchards.

Effect of cold stress on polyamine metabolism and antioxidant responses in chickpea.

Metabolic and genomic characteristics of polyamines (PAs) may be associated with the induction of cold tolerance (CT) responses in plants. Characteristics of PAs encoding genes in chickpea (Cicer arietinum L.) and their function under cold stress (CS) are currently unknown. In this study, the potential role of PAs along with the antioxidative defense systems were assessed in two chickpea genotypes (Sel96th11439, cold-tolerant and ILC533, cold-sensitive) under CS conditions. Six days after exposure to CS, the leaf H2O2 content and electrolyte leakage index increased in the sensitive genotype by 47.7 and 59 %, respectively, while these values decreased or remained unchanged, respectively, in the tolerant genotype. In tolerant genotype, the enhanced activity of superoxide dismutase (SOD) (by 50 %) was accompanied by unchanged activities of ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT) as well as the accumulation of glutathione (GSH) (by 43 %) on the sixth day of CS. Higher levels of putrescine (Put) (322 %), spermidine (Spd) (45 %), spermine (Spm) (69 %) and the highest ratio of Put/(Spd + Spm) were observed in tolerant genotype compared to the sensitive one on the sixth day of CS. Gamma-aminobutyric acid (GABA) accumulation was 74 % higher in tolerant genotype compared to the sensitive one on the sixth day of CS. During CS, the activity of diamine oxidase (DAO) and polyamine oxidase (PAO) increased in tolerant (by 3.02- and 2.46-fold) and sensitive (by 2.51- and 2.8-fold) genotypes, respectively, in comparison with the respective non-stressed plants (normal conditions). The highest activity of DAO and PAO in the tolerant genotype was accompanied by PAs decomposition and a peak in GABA content on the sixth day of CS. The analysis of chickpea genome revealed the presence of five PAs biosynthetic genes, their chromosomal locations, and cis-regulatory elements. A significant increase in transcript levels of arginine decarboxylase (ADC) (24.26- and 7.96-fold), spermidine synthase 1 (SPDS1) (3.03- and 1.53-fold), SPDS2 (5.5- and 1.62-fold) and spermine synthase (SPMS) (3.92- and 1.65-fold) genes was detected in tolerant and sensitive genotypes, respectively, whereas the expression of ornithine decarboxylase (ODC) genes decreased significantly under CS conditions in both genotypes. Leaf chlorophyll and carotenoid contents exhibited declining trends in the sensitive genotype, while these photosynthetic pigments were stable in the tolerant genotype due to the superior performance of defensive processes under CS conditions. Overall, these results suggested the specific roles of putative PAs genes and PAs metabolism in development of effective CT responses in chickpea.

Expression of acyl-lipid Delta12-desaturase gene in prokaryotic and eukaryotic cells and its effect on cold stress tolerance of potato.

We report the expression profile of acyl-lipid Delta12-desaturase (desA) gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic (Escherichia coli) and eukaryotic (Solanum tuberosum) cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase (licBM3) was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative (Petri dish test, electrophoregram and zymogram) and quantitative methods (spectrometry and gas liquid chromatography assays). The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18:2 and 18:3 fatty acids in primary transgenic plants was observed for lines 2 (73%) and 3 (41%). Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.

Comparative transcriptome provides molecular insight into defense-associated mechanisms against spider mite in resistant and susceptible common bean cultivars.

Common bean (Phaseolus vulgaris L.) is a major source of proteins and one of the most important edible foods for more than three hundred million people in the world. The common bean plants are frequently attacked by spider mite (Tetranychus urticae Koch), leading to a significant decrease in plant growth and economic performance. The use of resistant cultivars and the identification of the genes involved in plant-mite resistance are practical solutions to this problem. Hence, a comprehensive study of the molecular interactions between resistant and susceptible common bean cultivars and spider mite can shed light into the understanding of mechanisms and biological pathways of resistance. In this study, one resistant (Naz) and one susceptible (Akhtar) cultivars were selected for a transcriptome comparison at different time points (0, 1 and 5 days) after spider mite feeding. The comparison of cultivars in different time points revealed several key genes, which showed a change increase in transcript abundance via spider mite infestation. These included genes involved in flavonoid biosynthesis process; a conserved MYB-bHLH-WD40 (MBW) regulatory complex; transcription factors (TFs) TT2, TT8, TCP, Cys2/His2-type and C2H2-type zinc finger proteins; the ethylene response factors (ERFs) ERF1 and ERF9; genes related to metabolism of auxin and jasmonic acid (JA); pathogenesis-related (PR) proteins and heat shock proteins.

Tolerance responses in wheat landrace Bolani are related to enhanced metabolic adjustments under drought stress.

Physio-biochemical adaptations of wheat landraces may have great importance in their growth, survival and yield under drought stress. Here, we evaluated the effects of drought stress on some defense systems of wheat cultivar "Sistan" (drought-sensitive) and landrace "Bolani" (drought-tolerant). Under drought stress, Bolani plants showed lower increases in hydrogen peroxide content compared to Sistan ones, which was accompanied with significant decrease in malondialdehyde and electrolyte leakage indices. Increasing the transcript levels and activity of enzymatic and non-enzymatic antioxidants along with phenylpropanoid metabolites improved relative tolerance to drought-induced oxidative stress, particularly in Bolani plants, results which may be confirmed by a significant decrease in the damage indices. In the phenylpropanoid pathway, the biosynthetic pathway of total phenol, flavonoids and anthocyanins was more active than lignin-biosynthetic pathway, which could early respond to drought stress. These results may be confirmed by their negative significant correlations with damage indices as well as a non-significant correlation of lignin with most enzymatic and non-enzymatic antioxidants in plants. Lower decrease of chlorophyll (Chl) and carotenoid contents in Bolani plants compared to Sistan ones indicated the relative stability of photosynthetic pigments under drought stress. Our results suggested that integrating metabolic pathways could coordinately alleviate oxidative stress that can lead to introducing suitable genetic sources for drought tolerance.