Elicitation-Based Modulation of Shelf Life in Fruits: Physiological and Molecular Insights

The process of ripening involves physiological and biochemical events that become a concern during postharvest storage.We have documented different approaches for the preservation and maintenance of fruit quality during the postharvest period that are biocompatible and fully safe for consumption.Chemical residues that sustain sensory characteristics,such as color,flavor,aroma,and texture,are considered.In fruit ripening,both physical and chemical elicitors are described that regulate ethylene biosynthesis or its signaling for gene expression.The key regulatory enzymes,such as ACC synthase and ACC oxidase,for ethylene biosynthesis,are important for both climacteric and non-climacteric fruits.Anti-oxidizing genes that retain sensory characteristics are concerns in this respect.Chemical elicitors,including chitosan,polyamine,phenolics,lipopolysaccharide,silver derivatives,and nanocomposites,are described.Gas pressure,light wavelengths,relative humidity,cooling,and other environmental factors are important for improved postharvest storage.These elicitors maintain redox status by inhibiting the generation of reactive oxygen species(ROS)or their lysis.Growth regulators,including abscisic acid,auxin,brassinosteroids,jasmonic acid,and salicylic acid,are important for the regulation of ripening.Mechanical injuries,ionic imbalances,temperature variations,and tissue dehydration can occur irrespective of ripening cate-gories.The use of synthetic physiochemically active compounds is discussed in terms of physiological,metabolic,cellular,and molecular functions.Ethylene-induced autocatalytic processes,antioxidant cascades,epigenetic regulation,and homeodomain gene expression are discussed.Sugar–acid metabolism,dissolution of the cell wall,and direct or indirect production of secondary metabolites related to postharvest storage are mentioned regarding chilling storage.Elicitors and agrochemicals that trigger plant defense to increase secondary metabolite production are discussed for reducing fruit senescence during postharvest storage.

Molecular Evaluation of <i>Garcinia kola</i>Heckel Accessions Using RAPD Markers

The genetic relationships among twenty-five accessions of Garcinia kola using six Random Amplified Polymorphic (RAPD) primers were evaluated in this study. The highest volume of total genomic DNA (2218/μl) was recorded in ON4 from Ikare, while the highest DNA concentration of 1.93 gl was found in OS3 from Ilesa. The highest Polymorphic Information Content (PIC) and gene diversity of 93.77% and 0.94 respectively were revealed by primer OPO2 compared to other primers. The dendogram generated from Unweighted Pair Group with Mean Average (UPGMA) clustering delineated two groups, A and B, consisting of 21 and 4 accessions respectively. This study clearly showed the level of molecular diversity in the accessions and the information provided could be utilized for genetic improvement and conservation of Garcinia kola.

Phylogenetic, phylogeographic and divergence time analysis of Anopheles subpictus species complex using ITS2 and COI sequences

Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Transcriber Spacer 2(ITS2)and cytochrome C oxidase I(COI)sequences deposited at the GenBank.Methods:Seventy-five ITS2,210 COI and 26 concatenated sequences available in the NCBI database were used.Phylogenetic analysis was performed using Bayesian likelihood trees,whereas median-joining haplotype networks and time-scale divergence trees were generated for phylogeographic analysis.Genetic diversity indices and genetic differentiation were also calculated.Results:Two genetically divergent molecular forms of An.subpictus species complex corresponding to sibling species A and B are established.Species A evolved around 37-82 million years ago in Sri Lanka,India,and the Netherlands,and species B evolved around 22-79 million years ago in Sri Lanka,India,and Myanmar.Vietnam,Thailand,and Cambodia have two molecular forms:one is phylogenetically similar to species B.Other forms differ from species A and B and evolved recently in the above mentioned countries,Indonesia and the Philippines.Genetic subdivision among Sri Lanka,India,and the Netherlands is almost absent.A substantial genetic differentiation was obtained for some populations due to isolation by large geographical distances.Genetic diversity indices reveal the presence of a long-established stable mosquito population,at mutation-drift equilibrium,regardless of population fluctuations.Conclusions:An.subpictus species complex consists of more than two genetically divergent molecular forms.Species A is highly divergent from the rest.Sri Lanka and India contain only species A and B.

Frequency of the C677T Polymorphism of MTHFR, G20210A of Prothrombin and R506Q of Factor V Leiden in Type 2 Diabetics in Abidjan

In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.

Influence of Hemoglobin S Haplotypes on the Responses to Hydroxyurea Treatment in Children with Sickle Cell Disease in Abidjan, Côte d’Ivoire

Background: In Côte d’Ivoire so far, the circulating haplotypes have been inferred on the phenotypic profiling of SCD patients. The impact of the circulating haplotypes on the use of Hydroxyurea has not been assessed yet. Therefore the objective of this study is to identify in Abidjan the HbS haplotypes that modulate HU treatment responses. Methods: In a cross-sectional descriptive and analytical study, children aged 5 to 15 years with SCD, and carrying the hemoglobin phenotypes SSFA2 and SFA2, were recruited into a HU treatment cohort. Various parameters on the haplotypes and the outcomes of the treatment were analyzed. Results: Thirty nine children with SCD were included. The phenotypic profile of the cohort was 86.6% of SSFA2 and 15.4% of SFA2. Three haplotypes were found, the Benin haplotype, the Senegal haplotype, and an atypical one. The participants belonged to three genotypes, Benin/atypical (64.1%), Benin/Senegal (33.3%) and Senegal/Senegal (2.6%). Overall, HU treatment was successful in all haplotypes with 12 out of 39 patients failing treatment after 12 months in the Benin haplotype group. The association between HU treatment success and the Benin haplotype was found in terms of the decrease in the number of white blood cells and the students missing class. Conclusion: The study revealed that inferring haplotype based on the phenotypic profile could be inaccurate. The proportion of atypical haplotype that were not previously described in Côte d’Ivoire was high. All the haplotypes seemed to be associated with HU treatment success but some patients with Benin haplotype did not respond well.

克氏锥虫的新过氧化物酶基因克隆表达研究(英文)

目的为了探索克氏锥虫的谷胱甘肽依赖的过氧化物酶活性。方法使用基因克隆与表达鉴定的方法学对克氏锥虫谷胱甘肽依赖的过氧化物酶基因克隆和表达。结果一个全新的、18kDa的克氏锥虫单拷贝过氧化物酶基因被完全克隆到E.coli的表达载体pHrcHis上,并测序。蛋白序列分析表明与基因库谷胱甘肽依赖的过氧化物酶有高度的同源性。其表达蛋白被纯化分离,测定其酶活性显示了良好的活性,并能被亚油酸-氢过氧化物饱和。结论结果证实克氏锥虫仍然存在过氧化物酶介导的生物代谢。

Angiopoietin-2/angiopoietin-1 as non-invasive biomarker of cirrhosis in chronic hepatitis C

AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent assays(ELISA) in samples from 179 cirrhotic and non-cirrhotic CHC patients, classified according to the METAVIR system.Groups were compared by non-parametric MannWhitney U test. Subsequently, the association of peripheral concentrations of angiopoietins with the stage of fibrosis was analyzed using Spearman correlation test. Finally, the accuracy, sensitivity and specificity of circulating angiopoietins for cirrhosis diagnosis were determined by the study of the respective area under the curve of receiver operator characteristics(AUC-ROC).RESULTS Peripheral blood concentrations of Ang1 and Ang2 in CHC patients were significantly related to fibrosis. While Ang1 was decreased in cirrhotic subjects compared to non-cirrhotic(P < 0.0001), Ang2 was significantly increased as CHC progressed to the end stage of liver disease(P < 0.0001). Consequently, Ang2/Ang1 ratio was notably amplified and significantly correlated with fibrosis(P < 0.0001). Interestingly, the individual performance of each angiopoietin for the diagnosis of cirrhosis reached notable AUC-ROC values(above 0.7, both), but the Ang2/Ang1 ratio was much better(AUC-ROC = 0.810) and displayed outstanding values of sensitivity(71%), specificity(84%) and accuracy(82.1%) at the optimal cut-off(10.33). Furthermore, Ang2/Ang1 ratio improved the performance of many other previously described biomarkers or scores of liver cirrhosis in CHC.CONCLUSION Ang2/Ang1 ratio might constitute a useful tool for monitoring the progression of chronic liver disease towards cirrhosis and play an important role as therapeutic target.

The role and modulation of autophagy in experimental models of myocardial ischemia-reperfusion injury

A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial ischemia-reperfusion （I/R） injury. This tightly orchestrated cata-bolic cellular‘housekeeping’ process provides cells with a new source of energy to adapt to stressful conditions. This process was first described as a pro-survival mechanism, but increasing evidence suggests that it can also lead to the demise of the cell. Autophagy has been implicated in the pathogenesis of multiple cardiac conditions including myocardial I/R injury. However, a debate persists as to whether autophagy acts as a protec-tive mechanism or contributes to the injurious effects of I/R injury in the heart. This controversy may stem from several factors including the va-riability in the experimental models and species, and the methodology used to assess autophagy. This review provides updated knowledge on the modulation and role of autophagy in isolated cardiac cells subjected to I/R, and the growing interest towards manipulating autophagy to increase the survival of cardiac myocytes under conditions of stress-most notably being I/R injury. Perturbation of this evolutionarily conserved intracellular cleansing autophagy mechanism, by targeted modulation through, among others, mammalian target of rapamycin （mTOR） inhibitors, adenosine monophosphate-activated protein kinase （AMPK） modulators, calcium lowering agents, resveratrol, longevinex, sirtuin activators, the proapoptotic gene Bnip3, IP3 and lysosome inhibitors, may confer resistance to heart cells against I/R induced cell death. Thus, therapeutic ma-nipulation of autophagy in the challenged myocardium may benefit post-infarction cardiac healing and remodeling.

Assessment of heme oxygenase-1 （HO-1） activity in the cavernous tissues of sildenafil citrate-treated rats

Aim： To assess heine oxygenase-1 （HO-1） activity in the cavemous tissue of sildenafil citrate-treated rats. Methods： One hundred and ninety-two Sprague-Dawley male rats, divided into four equal groups, were investigated. Group 1, the control group, received regular animal chow; group 2 received sildenafil citrate by intragastric tube; group 3 received sildenafil and HO inhibitor （zinc protoporphyrin, ZnPP）; and group 4 received sildenafil and nitric oxide synthase （NOS） inhibitor L-nitroarginine methyl ester （L-NAME）. Twelve rats from each group were killed after 0.5 h, 1 h, 2 h and 3 h of drug administration. Then HO-1 activity, cGMP levels and NOS enzymatic activity in the cavernous tissues were estimated. Results： In cavemous tissue, HO-1 activity, NOS enzymatic activity and cGMP concentration increased significantly in sildenafil-treated rats compared to other groups throughout the experiment. Rats receiving either HO or NOS inhibitors showed a significant decrease in these parameters. HO- 1 cavemous tissue activity and NOS enzymatic activity demonstrated a positive significant correlation with cGMP levels （r = 0.646, r = 0.612 respectively; P 〈 0.001）. Conclusion： The actions of PDE5 inhibitor sildenafil citrate in the cavernous tissue are partly mediated through the interdependent relationship between both HO-1 and NOS activities.

Glycoprotein biomarkers for the detection of pancreatic ductal adenocarcinoma

Pancreatic cancer(Pa C) shows a clear tendency to increase in the next years and therefore represents an important health and social challenge. Currently, there is an important need to find biomarkers for PaC early detection because the existing ones are not useful for that purpose. Recent studies have indicated that there is a large window of time for PaC early detection, which opens the possibility to find early biomarkers that could greatly improve the dismal prognosis of this tumor. The present manuscript reviews the state of the art of the existing PaC biomarkers. It focuses on the anomalous glycosylation process and its role in PaC. Glycan structures of glycoconjugates such as glycoproteins are modified in tumors and these modifications can be detected in biological fluids of the cancer patients. Several studies have found serum glycoproteins with altered glycan chains in PaC patients, but they have not shown enough specificity for PaC. To find more specific cancer glycoproteins we propose to analyze the glycan moieties of a battery of glycoproteins that have been reported to increase in PaC tissues and that can also be found in serum. The combination of these new candidate glycoproteins with their aberrant glycosylation together with the existing biomarkers could result in a panel, which would expect to give better results as a new tool for early diagnosis of PaC and to monitor the disease.

Relationship between high sensitivity C-reactive protein and angiographic severity of coronary artery disease

Background Coronary artery disease(CAD)remains a leading cause of morbidity and mortality.Cytokines play a potential role in atherosclerosis pathogenesis and progression.We investigated the association between high sensitive C-reactive protein(hs CRP)and severity of CAD.Methods CAD patients were stratified according to hs CRP cut-off value into high levels hs CRP group(≥8.4 mg/L)and low levels hs CRP group(<8.4 mg/L).Severity of CAD was assessed according to artery stenosis degree and the number of vessel involved.Statistical analysis was performed using Statistical Package for the Social Sciences(SPSS,version 23.0).Results The mean age was 60.3±11.0 years.The level of hs CRP was increased and ranged from 0.2 to 1020.0 mg/L.Biochemical risk factors and severity of CAD didn’t show significant differences between the two groups.In multivariate linear analysis,cardiac troponin I(c Tn I)and serum amyloid A(SAA)were predictors of hs CRP.As shown in receiver operating characteristic(ROC)curve analysis performed in patients with ST-segment elevation myocardial infarction(STEMI)and compared to myonecrosis biomarkers,hs CRP(area under the curve(AUC):0.905;95%CI:0.844-0.966;P<0.001)could be a powerful predictor marker in evaluating the infarct size after myocardial infarction but not better than c Tn I.Conclusions Hs CRP levels were not associated with the severity of CAD but could be useful in the evaluation of myocardial necrosis in patients with STEMI.

Recombinant hybrid protein, Shiga toxin and granulocyte macrophage colony stimulating factor effectively induce apoptosis of colon cancer cells

AIM： To investigate the selective cytotoxic effect of constructed hybrid protein on cells expressing granulocyte macrophage colony stimulating factor （GM-CSF） receptor. METHODS： HepG2 （human hepatoma） and LS174T （colon carcinoma） were used in this study. The fused gene was induced with 0.02% of arabinose for 4 h and the expressed protein was detected by Western blotting. The chimeric protein expressed in E..coli was checked for its cytotoxic activity on these cells and apoptosis was measured by comet assay and nudear staining. RESULTS： The chimeric protein was found to be cytotoxic to the colon cancer cell line expressing GM-CSFRs, but not to HepG2 lacking these receptors. Maximum activity was observed at the concentration of 40 ng/mL after 24 h incubation. The IC50 was 20 ± 3.5 ng/mL. CONCLUSION： Selective cytotoxic effect of the hybrid protein on the colon cancer cell line expressing GMCSF receptors （GM-CSFRs） receptor and apoptosis can be observed in this cell line. The hybrid protein can be considered as a therapeutic agent.

Genetic biomarkers for hepatocellular cancer risk in a caucasian population

AIM To uncover novel genetic markers that could contribute to predicting hepatocellular carcinoma(HCC)susceptibility in Caucasians. METHODS The present retrospective case-control study compared genotype frequencies between a cohort of HCC cases and two,independent,HCC-free,age/sex-matched control groups.The HCC cohort comprised 192 homogeneous patients that had undergone orthotopic liver transplantation.The first control group comprised167 patients that were matched to the HCC cohort for the percentage of hepatitis B(HBV)and/or hepatitis C(HCV)infections.A second control group included192 virus-free,healthy individuals that were used to evaluate the generalizability of the identified predictive markers.All cases and controls were Caucasian.The three study populations were characterized with a panel of 31 markers derived from 21 genes that encoded key proteins involved in hepatocarcinogenesis-related pathways.The study end-point was to assess the association between genetic variants and HCC onset. RESULTS Five genetic markers were identified as risk factors for HCC in high-risk patients infected with HBV/HCV.According to a dominant model,reduced HCC risk was associated with three polymorphisms:ERCC1rs3212986(OR=0.46,95%CI:0.30-0.71,P=0.0005),GST-P1 rs1138272(OR=0.41,95%CI:0.21-0.81,P=0.0097),and CYP17A1 rs743572(OR=0.50,95%CI:0.31-0.79,P=0.0032).Conversely,according to a recessive model,increased HCC risk was associated with two polymorphisms:XRCC3 rs1799794(OR=3.70,95%CI:1.02-13.39,P=0.0461)and ABCB1 rs1128503(OR=2.06,95%CI:1.18-3.61,P=0.0111).These associations remained significant in a subgroup analysis,where patients were stratified according to viral status(HBV-or HCV-positive serology).Two variants exhibited a serology-specific effect:ABCB1 rs1128503(OR=4.18,95%CI:1.55-11.29,P=0.0048)showed an effect in the HBV-positive subgroup;and ERCC1 rs3212986(OR=0.33,95%CI:0.18-0.60,P=0.0003)showed an effect in the HCV-positive subgroup.Among the five markers identified,ERCC1 rs3212986(OR=0.43,P<0.0001)and CYP17A1 rs743572(OR=0.73,P=0.0310)had a different distribution in patients with HCC compared to healthy individuals.With a recursive partitioning approach,we also demonstrated that significant gene-gene interactions between ERCC1rs3212986,CYP17A1 rs743572,GST-P1 rs1138272,and the previously described UGT1A7*3 predictive marker,played a role in the complex trait of HCC susceptibility.CONCLUSION We identified five polymorphisms and interactions that contributed crucially to predicting HCC risk.These findings represented an important step towards improving HCC diagnosis and management.

Assessment of Some Biomarkers under Submergence Stress in Some Rice Cultivars Varying in Responses

Three rice varieties, significantly differed in their ability, when subjected to submergence have been studied in relation to physiological attributes. On account of oxidative stress, MDA content and carbonyl content were measured. The MDA content was maximally decreased in FR13A and minimally decreased in Swarna irrespective of shoots and roots. A higher increase in carbonyl content was found in Swarna followed by FR13A and Swarna Sub1A in both shoots and roots. The activity of antioxidant moieties like total phenolics content and flavonoid content were more increased under submergence than that in air except for Swarna. FR13A showed maximum increase in Phenolics and flavonoid content in both shoots and roots when subjected to submergence. A sharp increase in guaiacol peroxidase and glutathione reductase characterized the plants’ response to sub-mergence irrespective of varieties. The expression of Guaiacol peroxidase was increased in FR13A followed by Swarna Sub1A and Swarna. Glutathione reductase was measured in terms of oxidation of NADP(H) and both FR13A and Swarna Sub1A recorded maximum oxidation than Swarna under submergence. With regards to isozymic variation plants were differed to the intensities of poly-peptide, however not in numbers and may be suggestive for concomitant gene expression to sub-mergence. The analysis clarification for possible biomarkers with regards to cellular responses of rice plants under submergence has been anticipated.

Physio-Biochemical and Genetic Exploration for Submergence Tolerance in Rice (<i>Oryza sativa</i>L.) Landraces with Special References to <i>Sub</i>1 Loci

In the present study a group of four indigenous and less popular rice genotypes (Meghi, Panibhasha, Jabra and Sholey) reported by growers as submergence tolerant lines from flood prone areas of south Bengal were explored through study of nodal anatomy, physio-biochemical screening under submergence and genotyping with submergence tolerance linked rice microsatellite loci (RM loci). To identify the different allelic forms of different Sub1 compnents (Sub1A, Sub1B and Sub1C) among the studied lines, the genomic DNA of individual genotypes was amplified with three ethylene response factor like genes from Sub1 loci, located on rice chromosome 9. From the different physio-biochemical experiments performed in this investigation, it has been shown that Meghi and Jabra are the two probable potent genotypes which share common properties of both submergence tolerant and deep water nature whereas rest two genotypes (Sholey and Panibhasha) behave like typical deep water rice. The submergence tolerance property of Meghi was also confirmed from submergence tolerance linked SSR based genotyping by sharing with FR13A for some common alleles as reflected in fingerprint derived dendrogram. The rest of the genotypes shared a number of alleles and were included in a separate cluster. The common behaviour of Meghi and FR13A under submergence was also confirmed from genetic study of Sub1 loci through sharing of some common alleles for three Sub1 components (Sub1A, Sub1B and Sub1C loci). One SSR loci (RM 285) was identified as a potent molecular marker for submergence tolerance breeding programme involving these two selected rice lines (Meghi and Jabra) as donor plant through marker assisted selection.

An Exploratory Study on Allelic Diversity for Five Genetic Loci Associated with Floral Organ Development in Rice

Allelic diversity for five genetic loci (DL, FON4, OsMADS24, OsMADS45 and Spw1) associated with floral organ development were investigated among a small heterogeneous rice population which included one wild species (O. rufipogon Griffiths), one indigenous less popular natural floral organ mutant (O. sativa var. indica cv. Jugal), one indigenous normal line (O. sativa var. indica cv. Bhutmoori) and one improved high yielding line (O. sativa var. indica cv. IR 36). Detailed spikelet morphology showed that var. Jugal had variable number (1 - 3) of carpels within a single spikelet which was unique and resulted in variable (1 - 3) number of kernels within a single matured spikelet (grain). The genomic DNA of each investigated line was amplified with primer sequences designed from the selected genetic loci and the derived polymorphism profiles were used for study of allelic diversity for the studied loci. The derived genetic distances among the rice lines were used for dendrogram construction. In constructed dendrogram, the mutant genotype (Jugal) showed highest similarity with the wild rice (O. rufipogon) instead of the rice lines. To verify this finding, the genomic DNA of each studied line was also amplified with four SSR loci, tightly linked to saltol QTL, mapped to rice chromosome 1. The amplified products were screened for polymorphism and another dendrogram was constructed to reveal the genetic distance among the lines for selected salt tolerance linked SSR loci. In SSR derived dendrogram, the wild rice (O. rufipogon) got totally separated from the all three rice genotypes though all the studied four lines showed equal sensitivity for salt sensitivity in a physiological screening experiment. From the combined experiment, it can be concluded that genetic architecture of floral organ development loci in var. Jugal may have some uniqueness which is not present in normal rice but common to O. rufipogon, a species which is regarded as immediate progenitor of present day modern rice (O. sativa). Though this uniqueness was not confirmed by second set genetic loci associated with salt tolerance in rice, the information resulted from this experiment was preliminary and based only on allelic size (molecular weight of amplicon), which should be confirmed through sequence analysis for further analysis.

Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation. It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield. The detrimental effects of the complete submergence were recorded in generation of sucrose, starch, sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control （i.e. non-submerged） condition. The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity. Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity. However, under normal or control condition, there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity. Still, photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield. Finally, plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues. It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity （number of panicles, in this case） as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

Gene Expression Profiling during Wilting in Chickpea Caused by <i>Fusarium oxysporum</i>F. sp. <i>Ciceri</i>

Fusarium oxysporum f. sp. ciceri (Foc), one of the most important fungal pathogen of chickpea, is a constant threat to this crop plant. In the present study gene expression analysis of chickpea roots during Foc infection was performed using various approaches. cDNAs derived from total mRNA during infection process of susceptible (JG62)and resistant (Digvijay) cultivars, were amplified using random oligonucleotides. Sequence characterization of differentially expressed transcripts revealed their homology with many plant genes essential for various metabolic functions including defense. Further, expression patterns of specific candidate gene transcripts were analyzed in the Foc inoculated and uninoculated resistant and susceptible chickpea cultivars, on day 6 of infection. Semiquantitative RT-PCR analysis of defense related genes was performed using gene specific oligonucleotides in resistant and susceptible chickpea cultivars. The expression of fungal pathogenesis related genes and their race specific response was determined throughout the course of chickpea-Foc interaction. Temporal expression and race specific response of plant defense related and fungal virulence genes were studied in the resistant and susceptible cultivars of chickpea inoculated with three races of Foc highlighting the host-pathogen interactions. Few genes, involved in chickpea defense against Fusarium wilt which were not reported previously were unveiled in this study.

2,4-D Hyper Accumulation Induced Cellular Responses of Azolla pinnata R. Br. to Sustain Herbicidal Stress

In the present experiment with ongoing concentration(0µM,100µM,250µM,500µM and 1000µM)of 2,4-D,the responses of Azolla pinnata R.Br.was evaluated based on cellular functions.Initially,plants were significantly tolerated up to 1000µM of 2,4-D with its survival.This was accompanied by a steady decline of indole acetic acid(IAA)concentration in tissues with 78.8%over the control.Membrane bound H^(+)-ATPase activity was over expressed within a range of 1.14 to 1.25 folds with activator(KCl)and decreased within a range of 57.3 to 74.6%in response to inhibitor(Vanadate)application.With regards to IAA metabolism,plants recorded a linear increase with wall bound oxidase activity up to maximum concentration of 2,4-D.The variations were more moderated when wall bound IAA-oxidase recorded a linear increase proportionate to the 2,4-D concentrations.This was more extended with the presence of different isoforms of IAA-oxidase which was much more pronounced with distinct polymorphisms of expressed proteins,however,not independent to the 2,4-D concentrations.Polyamines like spermine,spermidine and putrescine(spm,spd and put)were not consistent in concentration with the dosages of 2,4-D.Besides these,plants were induced to apoplastic NAD(P)H oxidase activity maximally by 1.6 folds under 500µM 2,4-D over control.Still,putrescine responded more or less consistently and recorded maximally 11.9 folds at 500µM 2,4-D as compared to the control.NAD(P)H oxidase activity recorded maximally 1.6 folds against control and remain consistent throughout the concentrations of 2,4-D.GPX along with APX were more linear in responses through the concentration of 2,4-D except CAT as compared to control.On enzymatic antioxidative activity,peroxidases(GPX and APX)were overexpresed in a similar manner except for catalase with a non-significant rise.In stabilization of cellular redox,glutathione reductase attended maximum value by 2.45 folds at 1000µM evidenced with significant variations in protein polymorphism.The sensitivity of 2,4-D also appeared in Azolla with a maximum loss of nucleic acids as documented by the comet assay.Moreover,the Azolla might have some DNA damage protective activity as evident using frond extract with plasmid nick assay.Therefore,Azolla plants with its cellular responses is evident to sustain against the 2,4-D herbicidal stress and may be granted in bio remediation process for the contaminated soil.

Pb-Stress Induced Oxidative Stress Caused Alterations in Antioxidant Efficacy in Two Groundnut (<i>Arachis hypogaea</i>L.) Cultivars

Lead (Pb) is an important environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, a pot culture experiment was carried out using two groundnut cultivars (Arachis hypogaea L. cultivar K6 and cultivar K9) on plant growth, ROS levels, lipid peroxidation, and antioxidant metabolism using biochemical, histochemical methods. Plants were grown in pots for 14 days, in the botanic garden, and subjected to Pb-stress (0, 100, 200, 400 and 800 ppm) by adding Pb (NO3)2 solution and further allowed to grow for 10 days. The results showed that cultivar K6 registered lower Pb accumulation than cultivar K9, however, localization of Pb was greater in roots than leaves in both groundnut cultivars. The Pb-stress results in an increase in free radicals (O2?- and H2O2) generation in both groundnut cultivars, but more significantly in cultivar K9 than K6. Pb-stress also caused significant changes in the rate of peroxidation as shown in the levels of malondialdehyde (MDA) content in roots and leaves of both groundnut cultivars. Free proline, ascorbic acid (AsA) and non-protein thiol (NP-SH) contents were increased in cultivar K6 due to Pb-stress, but less in cultivar K9. Pb treated plants showed increased levels of antioxidant enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) glutathione reductase (GR) and glutathione S-transferase (GST). Isozyme band intensities of SOD, GPX and APX were more consistent with the respective changes in antioxidative enzyme activities. These results indicate that cultivar K6 possesses greater tolerance potential for Pb toxicity than cultivar K9.