S. K. Yadav

Drought stress responses in crops

Among the effects of impending climate change, drought will have a profound impact on crop productivity in the future. Response to drought stress has been studied widely, and the model plant Arabidopsis has guided the studies on crop plants with genome sequence information viz., rice, wheat, maize and sorghum. Since the value of functions of genes, dynamics of pathways and interaction of networks for drought tolerance in plants can only be judged by evidence from field performance, this mini-review provides a research update focussing on the current developments on the response to drought in crop plants. Studies in Arabidopsis provide the basis for interpreting the available information in a systems biology perspective. In particular, the elucidation of the mechanism of drought stress response in crops is considered from evidence-based outputs emerging from recent omic studies in crops.

Overview of Plant Stresses: Mechanisms, Adaptations and Research Pursuit

Biotic and abiotic stresses in crops are a major hurdle in attaining potential yield worldwide. Finding an approach to sustain high yields of crop plants under biotic and abiotic stresses is an important goal of agriculture researchers and stakeholders alike. Among the abiotic stresses, drought, salinity, temperature and heavy metal accumulation are the major environmental stresses, which adversely affect plant growth and productivity. In addition, biotic stresses primarily, plant diseaseses are a significant constraint to the production of about 25 important food and fiber crops. Changing climate compounds these adverse effects of stresses on crops. To cope with biotic and abiotic stress it is of paramount significance to understand plant responses to these stresses that disturb the homeostatic equilibrium at cellular and molecular level in order to identify a common mechanism for multiple stress tolerance at least in the case of abiotic stresses. An integrated systems approach is essential in the study of complex quantitative traits governing tolerance to multiple biotic and abiotic stresses. A detailed account of specially abiotic stresses and combating strategies to effectively counter them are discussed in this chapter.

In silico targeted genome mining and comparative modelling reveals a putative protein similar to an Arabidopsis drought tolerance DNA binding transcription factor in Chromosome 6 of Sorghum bicolor genome.

Arabidopsis Thaliana HARDY (AtHRD) is a gene with an APETELA 2 / Ethylene Responsive Factor (AP2/ERF) domain linked to improved performance under drought in rice. We hypothesized that the sorghum genome could possess a similar gene product and were motivated to conduct a computational genome scale mining for the protein and analyse its structural and functional properties. AtHRD sequence was used as a query to BLAST against the sorghum genome dataset followed by multiple alignment analysis. A homology model of the target was built using a template detected based on the pair-wise comparison of hidden Markov models for alignments. DNA docking with a matrix of homologous interface contacts was done. Functional and structural analysis of the query and target was conducted using various online servers.A High-scoring segment pair from Chromosome 6 of the sorghum genome in the region between 54948120 and 54948668 had 68 amino acid similarities out of the 184 residues and was 1.4% above twilight zone threshold. The homology model showed 86.8% residues in most favoured regions. The target protein which had an AP2/ERF domain when docked with GCC box DNA motif had conserved residues involved in binding; it had a long unstructured region beyond the AP2 domain with several motifs for the recognition of serine/threonine protein kinase group. The protein model showed that it could bind to a GCC box which is present in several drought responsive genes. The presence of possible signalling domains and intrinsic disorder in the target protein suggest that this could play a role in drought tolerance which is an inherent character of sorghum. These results offer a jumpstart for validation experiments which could pave the way for cis/trans genic improvement of a range of crops.

Physiological and Biochemical Basis of Extended and Sudden Heat Stress Tolerance in Maize

Effects of extended and sudden heat stress on various physiological and biochemical processes have been investigated in ten inbred lines of maize (Zea mays L.) at seedling stage. Among the various parameters studied, a significant decrease was observed in membrane stability, chlorophyll fluorescence and chlorophyll concentration under extended heat stress and sudden heat shock in sensitive genotypes which indicated their susceptibility to high temperature. However, heat tolerant genotypes exhibited less impact on these parameters which could be attributed to lesser oxidative stress injury. The free radical scavenging system in heat tolerant genotypes was observed to be better established as compared to heat sensitive genotypes. These findings suggested that the genotypes which performed better both under extended and sudden heat stress conditions could be partly due to their superior ability to cope up with oxidative damage caused by heat stress in maize.

Genotypic Variation in Physiological Traits Under High Temperature Stress in Maize

AbstractnMaize (Zea mays L.) is a major cereal crop in India and worldwide whose production and productivity are greatly affected by high temperature stress. Twenty-one maize genotypes were staggered sown and evaluated for the variations in different physiological traits under high temperature stress. Observations were recorded for net photosynthetic rate, transpiration rate, stomatal conductance, leaf temperature, canopy temperature, maximum quantum yield PSII photochemistry (Fv/Fm), SPAD, ASI, stover and grain yield. Meteorological data of cropping season for first and second date of sowings showed maximum and mean day time temperature of 37.6, 37.2 and 41.4, 37.5xa0°C, respectively, during reproductive stage. These temperatures were optimal for photosynthesis, fertilization and grain filling in early sown crop, while for the late sown crop, it was optimal for photosynthesis but above threshold and detrimental for fertilization and grain filling. Combined analysis of ANOVA showed that all the parameters were found significant with respect to genotypes (G), date of sowings (T) and their interaction (Gxa0*xa0T) except leaf temperature. The high temperature stress increased the plant stover weight due to increased photosynthesis coupled with maximum quantum yield PSII photochemistry which may improve the total plant growth. Results revealed that high temperature promoted the growth of vegetative plant parts but affected yield-related parameters. Higher temperatures during vegetative growth improved net photosynthetic rate resulting in higher total stover yield (28xa0%) at maturity. It impacted pollen viability and source to sink supply of photosynthates leading to reduced grain yield (13xa0%) in all genotypes.

An assessment of community participation in control and prevention of Japanese encephalitis in rural Uttar Pradesh

Background: Mosquito-borne disease poses a great burden to the society. It can be easily prevented through appropriate knowledge, positive attitude, and good practices. Japanese encephalitis (JE) is among one of these diseases, transmitted by culex mosquito. It is a major public health problem in India. n nObjective: The objective of this study was to assess the level of community participation in control and prevention of JE in rural area of Uttar Pradesh (UP). n nMaterials and Methods: It was a cross-sectional observation study. The study area was selected purposively. Non-probability consecutive sampling was done. A pre-designed and semi-structured questionnaire used for this study. Cronbach’s reliability test applied to access the internal consistency of various domains of knowledge, attitude, and practice (KAP). Assessment was done using a scoring system. Respondent level was defined as “goodâ€x9d and “poor.â€x9d A 60% cutoff point was taken for this. The sociodemographic characteristics, KAP of the sample was described using frequency and percentage table. KAP scores were calculated and categorized as “goodâ€x9d and “poorâ€x9d as abovementioned criteria. n nResults: A total of 401 households were interviewed during study period. Most of the respondents were aged between 21 and 35 years (60.1%). Almost 70.1% have pucca house. In 67.3% of houses, water drainage was unsatisfactory. Only 52.9% of respondents heard about JE. Knowledge about symptoms of JE was fair, while about its spread, reservoir of virus, breeding place of mosquito, and biting habit were poor. Attitude of one-third of respondent was satisfactory for all items asked. Practices were comparatively good. Although nearby stagnant water was a major issue. 80.5% respondents never removed this water. Correlation between knowledge and attitude was very strong (rs = 0.880). A bivariate logistic analysis revealed the sociodemographic variables such as gender, age, education, occupation, and category has no significant effect on KAP level of respondents. n nConclusion: There was a felt need of mass communication and education program specifically oriented for mosquito-borne disease. This can enhance positive attitude and good practices further.

SUNFLOWER TRAITS RESPONSE TO ELEVATED CO2 LEVELS UNDER COOL AND WARM SEASON CONDITIONS

SUMMARY A study was conducted in the Open Top Chambers (OTCs) to assess the influence of cool and warm season conditions on the response of sunflower (KBSH-1) to two elevated CO2 levels (550 and 700 ppm) and compare them with the response to an ambient level (390 ppm). The effect of elevated CO2 levels on biomass accumulation, seed yield and yield components were quantified in two seasons. Apart from the main effects of CO2 and different seasons, a significant interaction effect between CO2 levels and seasons was also observed. The CO2 levels differed significantly in influencing biomass accumulation, seed yield and number of seeds. Four Principal Components (PC) based on PC analysis explained about 85% of the variability in the response of traits influenced by CO2 levels in winter and summer seasons. In order to predict total dry weight, seed yield and harvest index obtained in winter and summer seasons, regression models of these variables were also calibrated and used through PC scores of different components. The analysis indicated that significant predictions could be made at ambient level with 550 ppm, compared to 700 ppm of CO2 level. The plant traits with a significantly higher loading of more than ± 0.70 on PCs were identified and have been recommended for future research in genetic improvement of sunflower, taking into account the change of climate due to elevated CO2 and temperature levels.

CA 19-9 in various gastrointestinal malignancies in an Indian population.

Mean (u/mL) 2B.33± 29.02 64.33 ± 73.47 151.93±7B.10 130.94 ± 79.06 13.BO± 12.47 B7.20±B7.57 23.75± 1B.50 195.50 ± 3.53 65.66±99.B1 16.79± 1B.57 Type of malignancy (n) CAoesophagus (6) CAstomach (24) CApancreas (30) CAgallbladder (3B) CAcolon (19) CArectum (20) CAanal canal (B) 110 in liver with unknown primary (4) Acute pancreatitis (12) Control (26) Box 1 Mean value of CA19-9 (carbohydrate antigen 19-9)