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Background: Nonalcoholic steatohepatitis (NASH) is associated with activation of liver fibrogenesis and predisposes to cirrhosis and associated morbi-mortality. A high fat high cholesterol diet (HFD) was provided to female albino rats to establish a NASH model. It is well known that the offspring of obese mothers have an increased risk of obesity and diabetes. The present study aimed at evaluating the ameliorative effects of ipriflavone (IP) as a natural food supplement on lipid metabolism, improving insulin sensitivity, reducing oxidative stress and inflammation, modifying metabolic risk factors and/or reduce brain damage, in both neonates and their dams. Materials and Methods: The present aim was achieved by evaluating the oxidative stress and antioxidant defense system biomarkers, as thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH), catalase, and superoxide dismutase (SOD) activities. In addition, the neurotransmitter acetylcholine (Ach) and acetylcholine esterase (AchE) activities, as well as levels of the apolipoprotein E4 (APOE4); β-secretase, hyper phosphor-tau and β-amyloid 42; 3-hydroxy- 3-methyl glutaryl coenzyme A reductase (HMG CoA R)” and COX-II by immunoblotting assays in the brain tissue of neonates and their dams in all the studied groups. Result: A very significant amelioration in acetylcholine and acetylcholine esterase neurotransmitters, Alzheimer’s makers (β-amyloid), antioxidants (reduced glutathione (GSH) contents, catalase (CAT) and superoxide dismutase (SOD); and inflammatory cytokines in NASH model is observed upon administrating ipriflavone (IP) as a natural food supplement. The multifunctional activities of ipriflavone as an antioxidant, anti-inflammatory and anti-insulin resistance drug were discussed and correlated with other investigations. Conclusion: Regarding steatohepatitis, the present study confirmed the anti-inflammatory effects of the ipriflavone (IP). Therefore, future studies should focus on hepatic fatty acid uptake, hepatic lipogenesis, and fatty acid oxidation and the role of IP in regulating hepatic fat metabolism. In addition, natural products like IP could be combined with the highly used pharmaceutical drugs to reduce the side effects of nonalcoholic steatohepatitis, and minimize progression of dementia. Moreover, the present study supports further attempts to heal the neural dysfunction via antioxidant and anti-inflammatory cascade activities using ipriflavone (IP).

It was suggested that Na+ ions could play a vital role in the growth of xero-halophyte Atriplex halimus. This study aims at investigating the impact of Na+ ions on the response of droughted A. halimus seedlings to the recovery in the natural habitat. The time-course regulation of recovery-responsive genes and the changes in physiological attributes during the recovery were examined in the absence (RW) or presence of 300 mM NaCl (RS). After 30 min and up to the end of the experiment, photosynthetic rate (A), stomatal conductance (gs) and leaf fresh and dry weights (FW) were enhanced by RW. Meanwhile, there was a sudden decline in (A) and (gs) rates after 30 min followed by a recovery in both rates after 3 h of RS. In response to RS, the change in carbon and nitrogen balance may act as a signal to regulate (A) and (gs) rates, in an attempt to control the upload of Na+ ions via transpiration. After 30 min or 3 h of the RW or RS onset, respectively, 1) the increase in 9-cis epoxycarotenoid dioxygenase (NCEDs) and abscisic acid (ABA) levels could stimulate the recovery-responsive genes rather than controlling (gs) and 2) the induction of ABA-dependent/independent transcription factors and recovery/salt-inducible genes could suggest their effective contributions to the recovery adaptation. After 5 d of the recovery onset, RS lowered FW by 82% whereas RW increased FW by 110%. Na+ ions could not enhance the performance of A. halimus seedlings during the recovery, perhaps, due to the non-constitutive expression of salt-responsive genes.

Overexpressing OsPIP2;4 in the two rice cultivars Giza178 and IR64 resulted in contrasting cultivar-dependent physiological attributes under control and drought conditions in the field. In the T3 plants, PIP2;4 expression was significantly higher in the leaves and roots of Giza178 under control but only in the roots under drought condition and higher in the leaves and roots of IR64 under control but not under drought condition compared with that in the corresponding wild types. The transgene improved the plant growth in Giza178 under both growth conditions but had no significant effect in IR64 under either condition. The transgenic lines of Giza178 recovered their leaf relative water content faster than those of the wild type in the afternoon and showed improved gas exchange parameters, water use efficiency, and grain yield, as a result of improved root hydraulic conductivity (Lpr) and xylem sap flow. No comparable responses were found in IR64 although Lpr and xylem sap flow were enhanced in the transgenic lines under the control condition only, suggesting that the positive effect of PIP2;4 on the well-watered leaves of IR64 was offset by the low root/shoot ratio and the inherent expression of other aquaporins. In the transgenic plants of IR64 under drought, PIP2;4 expression was not induced in the roots presumably due to an overriding post-transcription regulatory mechanisms, leading to the lack of changes in the Lpr and xylem sap flow and consequently, the plant growth, water relations, gas exchange, and grain yield were similar to the wild type. The data suggest that the outcome of overexpressing a single aquaporin gene depends on the plant architecture, internal responses to drought, and native expression of other aquaporins.

Most of the hot spots about rice research are related to roots; increasing rice yield is mainly associated with improving root traits. Understanding phenotype-gene regulation relationship in different rice cultivars can contribute to the genetic improvement of root system. The expression pattern of root genes in moroberekan (deep and thick roots and high root/shoot ratio "R/S") was compared to that in Giza178 and PM12 (numerous but shallow roots) and IR64 (fewer but deeper roots than the latter ones). In contrast to the other genotypes, moroberekan did not cease developing deep and thick roots even after 60 days from sowing, perhaps because of not only the consistent upregulation but also the interaction of root genes. Xylem sap flow was significantly higher even under drought (low water content) in moroberekan. Auxin signaling-related ARF12 and PIN1 genes could play key roles in improving root traits in response to low water or nitrogen content. Their concurrent upregulation was coincided with developing 1) deeper roots in moroberekan under drought, 2) thicker and deeper roots in PM12 under low nitrogen content (LN) and 3) new roots with thicker and deeper characteristics in the four genotypes after root trimming. The upregulation of PIN1 or ARF12 in Giza178 at LN, PM12 at drought or in IR64 under drought or LN did not greatly change the root traits. Hierarchical analysis showed that ARF12 and PIN1 were distantly related, but overlapped with other genes controlling root traits. Overexpression of ARF12 and PIN1 could improve root traits in rice cultivars.

Under high water availability, the maximum gas exchange was observed at noon in the expanding and expanded leaves. The expanded leaves showed lower gas exchange capacity due to the regulation of stomatal-movement genes. Under well-watered condition, stomatal conductance (gs) and photosynthetic rate (A) of expanding and expanded leaves of Atriplex halimus peaked at noon despite the midday decline in the leaf relative water content, suggesting deviation from typical isohydric behaviour. However, the expanding leaves had higher gs and A than the expanded ones. When light intensity was temporarily increased, A and gs were enhanced in both types of leaves though to a higher level in the expanding leaves. In well-watered expanded leaves: (1) A was mainly dependent on gs rather than photosynthetic capacity; gs was controlled by internal factors, thereby limiting water loss via transpiration (E); (2) the accumulation of total soluble sugars (TSS) along with increased Rubisco protein could be a subsidiary factor limiting A; (3) TSS and ABA seem to act in co-ordination to up-regulate ABA-dependent genes controlling gs and (4) the significant induction of DREBs suggests a role in maintaining high relative water content in these leaves compared to the expanding ones. In expanding leaves of well-watered plants, high A along with Rubisco down-regulation and elevated TSS suggests that A was regulated by signals coordinating carbon and nitrogen balance and the elevated ABA could be involved in regulating the hydraulic activity to enhance cell expansion and facilitate leaf growth. Both expanded and expanding leaves behaved in typical isohydric manner under water stress, which did not involve the accumulation of ABA suggesting that stomatal closure was primarily stimulated by hydraulic rather than chemical signals.

Effects of sodium nitroprusside (SNP; nitric oxide donor) treatments on enhancement of secondary metabolites production, oxidative stress mediators ( $$\mathrm{O}_{2}^{-}$$ ) accumulation and antioxidant defense enzymes of Potato Spunta Sp. suspension culture cells elicited by a fungal extract from phytophthora infestans mycelium. The obtained data confirmed the significant increase in various oxidative burst (super oxide anion, hydrogen peroxide and total glutathione) contents. The administration of various NO concentrations strongly decreased hydrogen peroxide concentration and superoxide anion levels. Moreover, the SNP treatments regulate elicitor-induced activation of phenylalanine ammonium-lyase and total soluble phenols accumulation. The highest concentrations of NO donor sodium nitroprusside potentiated elicitor-induced H2O2 production. On the other hand, the lowest H2O2 contents coincided with elicitation regulated various activities of enzymes superoxide-dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and Phenyl alanine ammonia lyase (PAL) activity, the decrease in H2O2 concentration was probably due to a direct reduction interaction of NO-H2O2. On the other hand, the addition of these previous NO treatments affects mRNA peroxidase gene expression using RT-PCR techniques. In general, the addition of lower concentrations of nitric oxide reduce the mRNA peroxidase activity on contrary, the higher concentrations induced the mRNA peroxidase activity, which induce the hypersensitive reactions against fungus infection.

The human respiratory syncytial virus is a common respiratory pathogen in children. Improved diagnosis of the virus is dependent on the development of tools for the rapid detection and estimation of the viral loads. In the current study, RT-qPCR using TaqMan hydrolysis probe based on the F gene detection was developed to identify and quantify hRSV in clinical samples. The assay was validated by comparing the results with a commercially available RT-qPCR kit. The newly developed assay was sensitive in detecting hRSV positive samples (59/126) which were equivalent to those detected by the commercial kit (57/126) with a detection limit of 1 × 102 copies/mL. A high correlation was found between the results of the newly developed assay and the commercial one. It was concluded that the newly developed RT-qPCR assay can be used as a sensitive detection tool for hRSV-A.

Zea mays L. is less tolerant to drought than Sorghum bicolor L. In the present study, we investigated the response of both plants to drought stress applied under field conditions by withholding water for 10 d. The plant growth in terms of shoot fresh and dry masses was more severely reduced in maize than in sorghum, consistently with reduction of leaf relative water content. Gas exchange was also more inhibited by drought in maize than in sorghum. The water use efficiency (WUE) of maize fluctuated during the day and in response to the drought stress. In contrast, sorghum was able to maintain a largely constant WUE during the day in the well-watered plants as well as in the stressed ones. Studying the expression of four aquaporin genes (PIP1;5, PIP1;6, PIP2;3, and TIP1;2) revealed that PIP1;5 in leaves and PIP2;3 in roots were highly responsive to drought in sorghum but not in maize, where they might have supported a greater water transport. The expression pattern of PIP1;6 suggests its possible role in CO2 transport in control but not droughty leaves of both the plants. TIP1;2 seemed to contribute to water transport in leaves of the control but not droughty plants. We conclude that PIP1;5 and PIP2;3 may have a prominent role in drought tolerance and maintenance of WUE in sorghum plants.

We tested the hypothesis that high root/shoot (R/S) in rice improves plant growth and yield when the shoot sink is expandable, and that in a genotype with exaggerated R/S ratio, the shoot growth is not limited by root resources. This study involved the three rice genotypes, Giza 178, PM12, and Moroberekan with a range of R/S ratios and shoot sink sizes. Root regrowth after trimming or high- and low-nitrogen treatments revealed that Moroberekan has consistently high root-favoured biomass partitioning than Giza 178 or PM12. Increasing the R/S ratios by detillering improved the culm growth in Giza 178 and PM12 (by 43.4 and 17.7% of control, respectively) but not Moroberekan, indicating that PM12 was closer to achieving its growth potential than Giza 178 but Moroberekan was operating at maximal shoot growth potential because of high R/S ratio and small sink size. Under drought, shoot growth, gas exchange, and grain yield correlated strongly with R/S ratio and root length density (RLD) in the droughted but not the well-watered plants. We further hypothesized that R/S ratio of Moroberekan was in excess of shoot requirement for optimum growth. Crossing Moroberekan to PM12 generated three F1 hybrids with intermediate R/S ratios but higher growth, gas exchange, and yield than either parent. We conclude that increasing the R/S ratio improved growth and yield in PM12 but not Moroberekan, because the shoot sink size was expandable in PM12. Moreover, lower R/S ratios than that of Moroberekan could support higher shoot growth if shoot sink is expandable.

Echinochloa crus-galli and Echinochloa colona mostly grown as weeds in different economic crops and cause losses in their yield. Flooding and Crop rotation ca not suppress these weeds. Herbicides are widely applied to control barnyard grasses. Bisbyric-sodium was applied at FRD (Field Recommended Dose) on both species, the results of preliminary experiment indicated that E. crus-galli was susceptible to bispyribac-sodium but E. colona was resistance. The Confirmation experiment for E. colona resistance indicated that herbicide effect on the biomass of plants which caused reduction in fresh and dry weight. The photosynthetic pigments were affected by herbicide, which decreased by increasing the herbicide concentration. While anthocyanins content were increased to protect the leaves from the stress of photoinhibitory light fluxes by absorbing the excess photons. The soluble and insoluble sugar content was increased by increasing the concentration of herbicide. The transcript level of ALS in E. colona was modified by different concentrations of herbicide. The present study indicated that ALS expression level was responsive to herbicide treatment. This suggests that ALS is a target site of bispyric-sodium. But 50% FRD can be considered as sub-lethal dose which upregulated the expression of ALS by 4 folds.

Zea mays L. is less tolerant to drought than Sorghum bicolor L. In the present study, weinvestigated the response of both plants to drought stress applied under field conditions bywithholding water for 10 d. The plant growth in terms of shoot fresh and dry weights was moreseverely reduced in maize than in sorghum as a result of drought stress, consistently with reductionof leaf relative water content (RWC). Gas exchange was also more greatly inhibited by drought inmaize than in sorghum. As a result, the water use efficiency (WUE) of maize was fluctuatedaccording to the time point during the day and in response to drought stress. In contrast, sorghumwas able to maintain largely constant WUE during the day in the well-watered plants as well asunder drought stress. This may indicate that sorghum was more efficiently controlled its waterstatus in particular water uptake than did maize. Studying the expression of four aquaporin genes(PIP1;5, PIP1;6, PIP2;3 and TIP1;2) revealed that most of the genes responded weakly to droughtstress except PIP2;3 which was highly responsive to drought in sorghum but not in maize roots,where it may have supported greater water uptake in sorghum, and thereby maintained higher leafRWC in sorghum than in maize and hence could account at least in part for the drought toleranceof sorghum as compared to maize. The outcome of this study is that PIP2;3 may have role indrought tolerance and maintenance of the WUE of sorghum plants compared to those of maize.

Application of NaCl at 75, 150 and 225 mM to 9-d-old seedlings of two wheat cultivars (Misr1 and Sakha93) for 15 days significantly decreased fresh and dry weights of only Sakha93. Growth parameters were most likely similar in both cultivars grown under normal conditions. Lipid peroxides and H2O2 were greatly accumulated in both cultivars particularly in Sakha93; significant increases were only detected in Misr1 treated with 225 mM. On the contrary, 150 and 225 mM NaCl led to great diminution in reducing power of Sakha93; however, there was no significant change in Misr1. In contrast to reducing power the phenolic contents were highly elevated in Sakha93 by NaCl at all concentrations but the effect of NaCl in Misr1 seemed to be nonsignificant. Also, all concentrations of NaCl decreased both protein content GSH in Sakha93 while the decrease in Misr1 was restricted to 225 mM. On the other hand, the activities of catalase (CAT), peroxidase (POD), glutathione-S-transferase (GST) and glutathione reductase (GR) were increased in Misr1 by 75 and 150 mM NaCl but inhibited in Sakha93 by all concentrations. The results of growth parameters suggest that Misr1 is a more tolerant cultivar to NaCl than Sakha93. The concomitant accumulation of MDA and H2O2 in Sakha93 and in the meantime the decrease in GSH reveal that ROS scavenging is less efficient in the more susceptible than the tolerant cultivar. Consequently, the cultivar Misr1 seemed to tolerate NaCl may be due to the more efficient induction of potential antioxidants to cope with salinity conditions.

Nine-day-old wheat seedlings were treated with NaCl at 75, 150, and 225 mM for 15 days in the absence or presence of 5 mM glycine. NaCl particularly at 150 and 225 mM led to significant reductions in fresh and dry weights, chlorophylls, carotenoids, Ca(2+), K(+), and K(+)/Na(+) ratio. Contrarily, there were significant accumulations in Na(+), malondialdehyde (MDA), H2O2, soluble sugars, and proline concomitant with inhibitions in enzymatic and non-enzymatic antioxidants and in Rubisco. In the meantime, the transcript level of alternative oxidase (AOX) was highly upregulated by NaCl; the upregulation was greatest with the lowest concentration. However, the transcript level of H(+)/Na(+) antiporter exchanger (NHX1) was decreased by 75 and 150 mM NaCl but increased by 225 mM. Similarly, the transcript level of salt overly sensitive 1 (SOS1) was upregulated by only 225 mM. Nonetheless, the application of glycine mostly overcame the varied impacts of NaCl on growth, MDA, H2O2, pigments, metabolites, and elements. Moreover, glycine elevated enzymatic and non-enzymatic antioxidants to reach most likely the levels of the respective control. On the contrary, much induction was detected in Rubisco. The transcript levels of AOX, NHX1, and SOS1 were further upregulated; the upregulation of AOX was most pronounced with the highest NaCl concentration in the presence of glycine and only with 75 and 150 mM NaCl for NHX1 and SOS1. The increase in antioxidants concomitant with the decrease in MDA and H2O2 reveals that ROS scavenging system became more efficient in NaCl-treated wheat following glycine application, concluding that glycine could ameliorate wheat tolerance to salinity. Moreover, lowering Na(+) by glycine and mitigation of the decreased K(+)/Na(+) ratio synchronous with recovery in growth reduction and stimulation of AOX, NHX1 and SOS1 may emphasize the role of glycine in stimulating gene expression for raising wheat tolerance to NaCl.

The present study investigated the develop- mental tolerance of Atriplex halimus to osmotic and/or ionic stress. A. halimus was exposed to NaCl (0, 100, 250 and 400 mM), KCl (0, 100, 250 and 400 mM) and sorbitol (0, 200, 500 and 800 mM) at the level of germination, seedling emergence and vegetative stages. The response of A. halimus to different salts was stage dependent especially to NaCl that had a remarkable effect on A. halimus growth at each stage. At the germination stage, the growth reduction could be attributed to osmotic effect and HRD may have a role in that osmotic sensitivity. At this stage, the accumulation of Na ? into vacuole could be a strategy for alleviating the osmotic effect. At the seedling emer- gence stage, the inhibition of growth could be mainly attributed to the ionic effect that may have resulted from excessive accumulation of Na ? along with inconsistent regulations of Na ? manipulating genes. A. halimus at the vegetative stage was an obligate halophyte with regulated mechanisms of tolerance to both ionic and osmotic com- ponents of salt stress. A. halimus exhibits glycophytic features at the early growth stages but it is an obligate halophyte at the vegetative stage.

Taif-roses are a famous rose type that cultivated i n Taif region and well known with their deep and in tensive fragrance in the Arabian World. Despite of the grea t economical importance of Taif-roses for the kingd om of Saudi Arabia, their genetic origin has not been yet elucidated. The present study was mainly aimed to assess the genetic relationship between Taif-roses and som e rose genotypes that grown in some kingdom neighboring countries using molecular markers and aromatic amino acids contents. Three Taif-roses genotypes namely Hada, Shafa-1 and Shafa-2 were compared to nine different rose genotypes that are grown in Egypt and S yria. Out of 12 RAPD, 8 ISSR and 8 SSR primers used, clear and repeatable band profile of 8, 6 and 7 primers was obtained from the three markers, respectively. Tota l of 111, 64 and 15 bands with polymorohism of 96.4, 90.6 and 93.3% were obtained using RAPD, ISSR and SSR, respectively. The discriminating power of the three markers has led to efficient grouping of the 12 ros e genotypes using Unweighted Pair Group Method (UPGMA). Among the 12 genotypes, Syrian-Gory rose shown the highest genetic similarity of 75, 92 and 65% with the three Taif-roses genotypes Hada, Shafa-1 and Shafa-2, respectively. The established dendr ogram was clearly separated the 12 rose genotypes into fo ur major groups in which the three Taif-roses genot ypes were clustered in the same group with the Gory rose -Syrian genotype. Moreover, the data revealed that among the studied rose genotypes, the contents of aromati c amino acids in Syrian-Gory rose and the Taif rose -Hada was the highest and followed by the Egyptian Balady rose 1. While Dutch rose 1, 2, 3 and Dutch tulip 1 , 2 were recorded to be the lowest. Together, these res ults indicate that Taif-rose has closed genetic rel ations to the Gory rose-Syrian cultivated in Syria. Additiona lly, a reproducible protocol for In vitro propagation, of Taif-rose genotype (Hada) was developed.

Phylogenetic and evolutionary patterns of the six internal genes of an equine H5N1 influenza A virus isolated in Egypt on 2009 were analyzed using direct sequencing. All of the internal genes of the equine H5N1 strain showed a genetic pattern potentially related to Eurasian lineages. Variable dendrogram topologies revealed an absence of reassortment in the equine strain while confirming its close relatedness to other Egyptian H5N1 strains from human and avian species. The equine strain is characterized by a variety of amino acid substitutions in six internal proteins compared to the available Egyptian H5N1 strains. Interestingly, the equine strain displayed amino acids in the PB2, PA, M2 and NS2 proteins that are unique among the available H5N1 sequences in the flu database, and their potential effect on virulence needs to be further investigated.

The tolerant C3 plant Pancratium maritimum L. was used to investigate the contribution of photorespiration to the oxidative load under salt and drought stress. 7-weeks old plants were salt-stressed by 150 or 300 mM NaCl or drought-stressed by withholding water for 11 or 21 days. The growth, photosynthesis (A) and transpiration rates (E) were reduced by all stress treatments proportionally to the severity of stress. The rate of photorespiration was remarkably higher under moderate stresses than under severe stresses as revealed by large increase in the photorespiratory indicators Gly/Ser ratio and glyoxylate content and as substantiated by higher expression levels of photorespiratory enzymes. Nonetheless, indicators of oxidative stress namely, malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents showed greater increase under severe stresses suggesting that the increase in the oxidative load under severe stresses is independent of photorespiration rate. The lower contents of MDA and H₂O₂ under moderate stresses (compared to these under severe stresses) in spite of the strong upregulation of photorespiration indicate efficient detoxification of photorespiration-generated H₂O₂ as shown by efficient upregulation of catalase (CAT) and peroxidase (POD). It is thus concluded that photorespiration may not be major contributor to the oxidative load under salt and drought stress.

Trifolium alexandrinum L. was transformed with the Arabidopsis HARDY gene that belongs to the stress-related AP2/ERF (APETALA2/ethylene responsive element binding factors) superfamily of transcription factors. The fresh weights of the transgenic lines L2 and L3 were improved by 42 and 55% under drought stress and by 38 and 95% under salt stress compared to the wild type, respectively. The dry weights were similarly improved. Overexpression of HARDY improved the instantaneous water use efficiency (WUE) under drought stress by reducing transpiration (E) and under salt stress by improving photosynthesis (A), through reducing Na+ accumulation in leaves, and reducing E. However, HARDY improved the growth of drought-stressed transgenic plants as compared to the wild type by delaying water depletion from soil and preventing rapid decline in A. L2 and L3 had thicker stems and in case of L3, more xylem rows per vascular bundle, which may have made L3 more resistant to lodging in the field. Field performance of L2 and L3 under combined drought and salt stress was significantly better than that of the wild type in terms of fresh and dry weights (40%, 46% and 31%, 40%, respectively). The results provide further evidence for the efficiency of overexpression of a single gene in improving tolerance to abiotic stress under field conditions.

In the present study, Na+ manipulating genes could contribute not only to ion homeostasis but also to growth stimulation with exposing the halophyte Atriplex halimus L. to moderate NaCl concentration. The stimulation of growth was attributed to Na+ accumulation inside the vacuole leading to increase leaf cell size as well as accelerate leaf cell division. Increasing the assimilatory surface could result in enhancing the photosynthetic rate. The reduction of A. halimus growth compared to optimum growth at 50 and 200 mM NaCl could be attributed to osmotic effect rather than the ionic one of salt stress. The inhibition of photosynthesis seemed to be resulted from limitation of CO2 due to the osmotic effect on stomatal conductance rather than the activity loss of photosynthetic machinery. The depletion of starch content along with the increase in sucrose content could imply that photosynthesis may be a limiting for A. halimus growth. The fast coordinate induction of Na+ manipulating genes could reveal that the tolerance of A. halimus to high concentrations evolved from its ability to regulate and control Na+ influx and efflux. V-H+-PPase may play a vital role in A. halimus tolerance to osmotic and/or ionic stress due to its kinetics of induction. It seemed that H+-ATPase plays a pivotal role in A. halimus tolerance to stress due to the increase in its protein level was detected with all NaCl concentrations as well as with PEG treatments. Both of these genes might be useful in improving stress tolerance in transgenic crops.

Studying the regulation of stress inducible genes can lead to understanding of the mechanisms by which halophytes maintain growth and thrive under abiotic stress. Verifying whether ionic or osmotic components of salt stress control the regulation of Dehydration Responsive Element- binding transcription factor (DREB) was investigated in the present study. DREB belongs to AP2/EREB group that is induced under abiotic stress and regulates many stress inducible genes that contain DRE binding sites in their promoters. DREB in Atriplex halimus was regulated by the osmotic component but not by the ionic one of salt stress. It seemed that DREB was not involved in the regulation of sodium manipulating genes like NHX1, SOS1 or H +-PPase. Moreover, DREB could be involved directly of indirectly in CMO regulation because of timing of induction. Also, DREB was the most upregulated gene under salt (fivefold) and drought (twofold) conditions, which reinforced the importance of this gene in A. halimus tolerance to stress. Moreover, its constitutive expression under normal conditions also indicated its involvement in other growth and developmental programs. The tolerance of A. halimus and of halophytes, in general, could be attributed to the constitutive expression of its genes and differences in protein structures between halophytes and glycophytes.

In this study, the physiological and molecular defects leading to growth reduction under salt stress in Egyptian clover (Trifolium alexandrinum L.) were investigated. Time-course response of growth to salt stress with 200 mM Na+ and/or Cl− showed that significant reduction in the growth of the stressed plants was delayed until the sixth day of stress indicating that the plant is more resistant to the osmotic component of salt stress. The rate of photosynthesis started to decrease significantly from the third day of stress although the rate of transpiration decreased to 18.4% of the control after 2 h indicating that reduction in photosynthetic rate may have not been essentially due to CO2 limitation. The mutual relationships of photosynthesis and growth are discussed and evidence is provided that growth reduction is largely a consequence rather than a cause of inhibition of photosynthesis. Data also shows that inhibition of photosynthesis could have resulted from excessive accumulation of Na+ in the leaves along with downregulation of Na+-sequestering genes (NHX1, H+-PPase and H+-ATPase) that may have led to loss of the efficiency of Na+ sequestration into the vacuole and subsequent damage to photosynthesis. The role of HRD gene in regulating transpiration is discussed.

Salt tolerance is a complex trait involving the coordinated action of many gene families that perform a variety of functions such as control of water loss through stomata, ion sequestration, metabolic adjustment, osmotic adjustment and antioxidative defense. In spite of the large number of publications on the role of antioxidative defense under salt stress, the relative importance of this process to overall plant salt tolerance is still a matter of controversy. In this article, the generation and scavenging of reactive oxygen species (ROS) under normal and salt stress conditions in relation to the type of photosynthesis is discussed. The CO2 concentrating mechanism in C4 and CAM plants is expected to contribute to decreasing ROS generation. However, the available data supports this hypothesis in CAM but not in C4 plants. We discuss the specific roles of enzymatic and non enzymatic antioxidants in relation to the oxidative load in the context of whole plant salt tolerance. The possible preventive antioxidative mechanisms are also discussed.

In this study we describe the selection and characterization of barnyard grass (Echinochloa crusgalli L.) mutants (fows B) with vegetative salt tolerance as compared to a previously described mutant with salt tolerant germination (fows A3). Salt tolerance of both types of mutants was characterized in two distinctive stages of plant development, germination and vegetative growth. About 46% of fows A3 seeds germinated in 300 mM NaCl but none of the seeds of the wild type or fows B mutants were able to germinate in this salt concentration. However, fows B mutants showed significantly higher fresh weights compared to the wild type and the fows A3 mutant when grown in the presence of 200 mM NaCl for 25 days. This indicated that fows B mutants are more salt tolerant than fows A3 mutant as well the wild type. The vegetative salt tolerance of the fows B mutants depended mainly on maintaining more efficient photosynthetic machinery, by keeping significantly higher chlorophyll and Rubisco contents and accumulating soluble sugars particularly sucrose. In addition, fows B mutants had significantly lower malondialdehyde (MDA) contents than did fows A3 and the wild type. This was apparently the result of higher activities of catalase (CAT) and peroxidase (POD) in fows B mutants compared to the wild type and fows A3, indicating that more efficient control of reactive oxygen species correlates with salt tolerance. However, proline accumulation and K+/Na+ ratio did seem to be essential to vegetative salt tolerance. The vegetative salt tolerance mechanisms in fows B mutants were weakly expressed in the wild type and fows A3 mutant. The results provide evidence that salt tolerance during germination and vegetative growth could involve different mechanisms.

Trifolium alexandrinum L. (Egyptian clover) is one of the most important forage crops in the world. Its regeneration in tissue culture has been described in a few reports but the efficiency, accurate time scales and applicability to various genotypes of the described procedures are uncertain. Therefore their suitability for genetic transformation is unclear. In this study, were report new fast procedures for regeneration of Egyptian clover that are applicable to the regeneration of various genotypes (Mescawi-ahaly, Sakha3 and Sakha4). Shoots were regenerated from intact and wounded cotyledons as well as hypocotyls of Mescawi-ahaly on naphthaleneacetic acid/benzyladenine (NAA/BA) and naphthaleneacetic acid/thidiazuron (NAA/TDZ) media. The highest shoot regeneration frequencies were obtained from intact cotyledons on NAA/BA (0.05 mg l−1 NAA combined with 2.0 mg l−1 BA) and NAA/TDZ (0.05 mg l−1 NAA combined with 1.0 mg l−1 TDZ) media (66.2 and 43.1% respectively) compared to 18.4 and 10.1% for wounded cotyledons on NAA/BA and NAA/TDZ respectively. 21.0% shoot regeneration frequency was observed for hypocotyls on NAA/BA (2.0 mg l−1 NAA combined with 0.5 mg l−1 BA) medium but no regeneration was obtained on NAA/TDZ medium. Rooting of the regenerated shoots was induced on indole butyric acid (IBA: 0.24 mg l−1) or NAA (2.0 mg l−1) media where IBA medium supported significantly higher frequencies of rooting as well as survival of the whole plantlets after transfer to soil. However, the rooting and survival frequencies also depended on the type of explant and the medium used for shoot regeneration. The two cultivars Sakha3 and Sakha4 were regenerated using the culture conditions optimized for Mescawi-ahaly with comparable efficiencies, indicating that the described procedure is not genotype dependent. The time scale of whole plantlet regeneration ranged from 7.5 weeks for intact and wounded cotyledons to 10 weeks for hypocotyl explants.

Improving salt tolerance of economically important plants is imperative to cope with the increasing soil salinity in many parts of the world. Mutation breeding has been widely used to improve plant performance under salinity stress. In this study, we have mutagenized Echinochloa crusgalli L. with sodium azide and three selected mutants (designated fows A) with salt tolerant germination. Their vegetative growth was compared to that of the wild type after short-term and long-term salt stress. The germination of the three fows A mutants in the presence of inhibitory concentrations of NaCl, KCL, and mannitol was better than that of the wild type. Early growth of the mutants in the presence of 200 mM NaCl was also better than that of the wild type perhaps due to improved K+ uptake and enhanced accumulation of sugars particularly sucrose at least in two mutants. But the three mutants and the wild type responded similarly to long-term salt stress. The tolerance mechanisms during short-term and long-term salt stress are discussed.

Rice has shallow, weak roots, but it is unknown how much increase in yield potential could be achieved if the root/shoot ratio is corrected. Removing all tillers except the main one, in a japonica (Sakha 101) and an indica (IR64) rice cultivar, instantly increased the root/shoot ratio from 0.21 to 1.16 in Sakha 101 and from 0.16 to 1.46 in IR64. Over 30 days after detillering, the root/shoot ratios of the detillered plants decreased to 0.49 in Sakha 101 and 0.46 in IR64 but remained significantly higher than in the controls. The detillered plants showed two- or fourfold increase in the main tiller fresh weight, as a consequence of more positive midday leaf relative water content (RWC), and consistently higher rates of stomatal conductance and photosynthesis, but not transpiration, compared with the controls. The enhanced photosynthesis in Sakha 101 after detillering resulted from both improved water status and higher Rubisco contents whereas in IR64, increasing the Rubisco content did not contribute to improving photosynthesis. Detillering did not increase the carbohydrate contents of leaves but prevented starch depletion at the end of grain filling. The leaf protein content during vegetative and reproductive stages, the grain filling rate, the number of filled grains per panicle were greatly improved, bringing about 38.3 and 35.9% increase in the harvested grain dry weight per panicle in Sakha 101 and IR64, respectively. We provide evidence that improving the root performance by increasing the root/shoot ratio would eliminate the current limitations to photosynthesis and growth in rice.

This study aimed at specifying the reasons of unbalanced water relations of rice in the field at midday which results in slowing down photosynthesis and reducing water use efficiency (WUE) in japonica and indica rice under well-watered and droughted conditions. Leaf relative water content (RWC) decreased in the well-watered plants at midday in the field, but more dramatically in the droughted indica (75.6 and 71.4%) than japonica cultivars (85.5 and 80.8%). Gas exchange was measured at three points during the day (9:00, 13:00 and 17:00). Leaf internal CO2 (Ci) was not depleted when midday stomatal depression was highest indicating that Ci was not limiting to photosynthesis. Most aquaporins were predominantly expressed in leaves suggesting higher water permeability in leaves than in roots. The expression of leaf aquaporins was further induced by drought at 9:00 without comparable responses in roots. The data suggest that aquaporin expression in the root endodermis was limiting to water uptake. Upon removal of the radial barriers to water flow in roots, transpiration increased instantly and photosynthesis increased after 4h resulting in increasing WUE after 4h, demonstrating that WUE in rice is largely limited by the inadequate aquaporin expression profiles in roots.

HCV is a major etiological agent of liver disease with a high rate of chronic evolution. The virus possesses 6 genotypes with many subtypes. The rate of spontaneous clearance among HCV infected individuals denotes a genetic determinant factor. The current study was designed in order to estimate the rate of HCV infection and ratio of virus clearance among a group of infected patients in Saudi Arabia from 2008 to 2011. It was additionally designed to determine the genotypes of the HCV in persistently infected patients. HCV seroprevalence was conducted on a total of 15,323 individuals. Seropositive individuals were tested by Cobas AmpliPrep/Cobas TaqMan HCV assay to determine the ratio of persistently infected patients to those who showed spontaneous viral clearance. HCV genotyping on random samples from persistently infected patients were conducted based on the differences in the 5′untranslated region (5′UTR). Anti-HCV antibodies were detected in 7.3% of the totally examined sera. A high percentage of the HCV infected individuals experienced virus clearance (48.4%). HCV genotyping revealed the presence of genotypes 1 and 4, the latter represented 97.6% of the tested strains. Evidences of the widespread of the HCV genotype 4 and a high rate of HCV virus clearance were found in Saudi Arabia.

The growth of the wild-type and three salt tolerant mutants of barnyard grass (Echinochloa crusgalli L.) under salt stress was investigated in relation to oxidative stress and activities of the antioxidant enzymes superoxide dismutase (SOD: EC 1.15.1.1), catalase (CAT: EC 1.11.1.6), phenol peroxidase (POD: EC 1.11.1.7), glutathione reductase (GR: EC 1.8.1.7) and ascorbate peroxidase (APX: EC 1.11.1.1). The three mutants (fows B17, B19 and B21) grew significantly better than the wild-type under salt stress (200 mM NaCl) but some salt sensitive individuals were still detectable in the populations of the mutants though in smaller numbers compared with the wild-type. The salt sensitive plants had slower growth rates, higher rates of lipid peroxidation and higher levels of reactive oxygen species (ROS) in their leaves compared with the more tolerant plants from the same genotype. These sensitivity responses were maximized when the plants were grown under high light intensity suggesting that the chloroplast could be a main source of ROS under salt stress. However, the salt sensitivity did not correlate with reduced K(+)/Na(+) ratios or enhanced Na(+) uptake indicating that the sensitivity responses may be mainly because of accumulation of ROS rather than ion toxicity. SOD activities did not correlate to salt tolerance. Salt stress resulted in up to 10-fold increase in CAT activity in the sensitive plants but lower activities were found in the tolerant ones. In contrast, the activities of POD, APX and GR were down regulated in the sensitive plants compared with the tolerant ones. A correlation between plant growth, accumulation of ROS and differential modulation of antioxidant enzymes is discussed. We conclude that loss of activities of POD, APX and GR causes loss of fine regulation of ROS levels and hence the plants experience oxidative stress although they have high CAT activities.

Proline is an important component of salt-stress responses of plants. In this study the role of proline as part of salt-stress signalling in the desert plant Pancratium maritimum L. was examined. The data showed that salt-stress brought about a reduction of the growth and protein content, particularly at 300 mM NaCl, that was significantly increased by exogenous proline. In the leaves, salt-stress up-regulated ubiquitin, a small protein targeting damaged proteins for degradation via the proteasome, up to 5-fold as detected by western blotting. This change was also affected by proline even in non-stressed leaves. However, salt-stress resulted in a decrease in the amount of ubiquitin-conjugates, particularly in the roots, and this effect was reversed by exogenous proline. Severe salt-stress resulted in an inhibition of the antioxidative enzymes catalase and peroxidase as revealed by spectrophotometric assays and activity gels, but the activity of these enzymes was also maintained significantly higher in the presence of proline. Salt-stress also up-regulated several dehydrin proteins, analysed by western blotting, even in non-stressed plants. It is concluded that proline improves the salt-tolerance of Pancratium maritimum L. by protecting the protein turnover machinery against stress-damage and up-regulating stress protective proteins.