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Maize, a moderately salt sensitive crop, first experiences osmotic stress that cause reduction in plant growth under salt stress. Fluctuation in cell wall elongation is one of the reasons of this reduction. Along with others, two important proteins expansins and xyloglucan endotransglucosylase are involved in regulation of cell wall elasticity, but the role of epigenetic mechanisms in regulating the cell wall related genes is still elusive. The present study was conducted with the aim of understanding the role of DNA methylation in regulating ZmEXPB2 and ZmXET1 genes. One salt sensitive and one salt tolerant maize cultivar was grown under hydroponic conditions at different levels of salt stress: T1 = 1 mM (control), T2 = 100 mM and T3 = 200 mM in three replicates. DNA and RNA were extracted from roots. After bisulfite treatment, Methyl Sensitive PCR was used for the DNA methylation analysis. It was revealed that fragment in promoter of ZmEXPB2 gene showed high level of DNA methylation under T1 in both varieties. Comparison of different stress treatments revealed decrease in DNA methylation with the increase in salt stress, significantly lower methylation appearing in T3. Similarly, the fragment in promoter of ZmXET1 gene also showed high levels of DNA methylation in T1. When different treatments were analysed, this gene significantly hypomethylated at T2 which continued to decrease in T3 in sensitive variety but remain stable in tolerant variety. Although, further in-depth analysis is required, our results demonstrate region-specific and genotype-specific methylation shift in the promoter of the ZmEXPB2 and ZmXET1 genes when subjected to the salt stress confirming the epigenetic regulation of these genes under stress conditions.

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Stomatal conductance is an important heat avoidance mechanism and its association with higher yield and heat resistance has been established in Pima cotton. Experiments were carried out on upland cotton under heat-stressed and non-stressed greenhouse and field regimes, to understand the impact of heat-stressed and non-stressed environments on the genetic and combining ability variations for stomatal conductance. The experimental material comprised 8 upland cotton cultivars and their 15 F 1 cross combinations obtained in a line × tester mating arrangement. The results showed high genetic variability for stomatal conductance in a single environment, but low genetic variability across environments, due to the higher magnitude of the environmental interaction, especially that caused by temperature regimes. The interaction effect of temperature regimes also substantially modified general and specific combining ability variations for stomatal conductance. The relative contributions of general and specific combining abilities to total phenotypic variation for stomatal conductance also underwent a great change across field temperature regimes. The non-stressed regime favoured the expression of genes causing the additive type of genetic variability. The heat-stressed field regime, however, favoured the expression of both additive and non-additive types of genetic variation for stomatal conductance in upland cotton. Recurrent selection for the accumulation of favourable genes for general combining ability under non-stressed conditions was suggested for improving stomatal conductance in applied cotton breeding programmes.

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European Journal of Microbiology and Immunology
Abdul Malik Tareen
M. Rafique
A. Wadood
M. Qasim
H. Rahman
S. H. Shah
K. Khan
, and
G. S. Pirkani


Malaria is a serious global health challenge, which is responsible for more than one million deaths a year. Malarial infection is more prevalent in developing countries including Pakistan. Significant efforts have been made to control malaria; however, due to socio-environmental factors, it remains a frequent problem in Quetta. The present study was undertaken to determine the malarial incidence, species prevalence, and its demographic evaluation in human population of Quetta, Pakistan. A total of 1831 subjects, comprising 1072 male and 759 female presenting symptoms of malaria, were included in this study. Blood samples from clinically suspected individuals were subjected to the standard immunochromatographic and malaria parasite smear analysis for malaria diagnosis. Out of 1831 subjects, 338 (18.45%) patients were positive for malarial parasite while the species prevalence was found as 276 (81.66%) and 62 (18.34%) for Plasmodium vivax, and Plasmodium falciparum, respectively. Furthermore, seasonal variations gradual increase in the prevalence rate. The age group of 21–30 years (30.47%) was found more prone to malaria. The suspected malaria cases were found more frequent in rural (72.1%) as compared to urban (27.9%). In addition, the malaria burden was high in urban area (22.89%) population as compared to the rural area (16.74%) population. It was observed that the highest disease occurrence was caused by P. vivax, which reflects a serious threat for public health. The current findings will be helpful to plan effective strategies to prevent and control malaria in this area.

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