Mechanisms of partial plant resistance to diamondback moth (Plutella xylostella) in brassicas

Artificial diet studies were used to differentiate among physical and chemical mechanisms affecting the suitability to diamondback moth (Plutella xylostella L.), of 16 food substrates obtained by growing four different brassicas in the glasshouse or field and measuring the pest's performance on either leaf discs or a diet incorporating leaf powders. Leaves of Chinese cabbage and the cabbage cultivar 'Minicole' were, respectively, the most and least suitable leaves for the insect, but this ranking was reversed on artificial diet. Leaves of glasshouse-grown plants were more suitable than those of plants grown in the fields. Differences in the suitability of leaves to diamondback moth appeared to be largely determined by leaf toughness and surface wax load. Concentrations of individual glucosinolates in the brassicas probably acted as phagostimulants, so increasing their intrinsic susceptibility to diamondback moth, but the effect of the physical factors appeared more important

Ecobiology and behavioural aspects of the pink bollworm, Pectinophora gossypiella (Saund.) (Lepidoptera: Gelechiidae) infesting cotton

The ecobiology of pink bollworm, Pectinophora gossypiella (Saunders) infesting cotton (cv. NHH 44) was studied at fluctuating ambient temperatures and also on artificial diet. No significant differences were observed in life-cycle. However, the influence of declining temperature was evident in extending the life-cycle period. This was supplemented with an increse in the duration of life-cycle, vit, 38.95,42.01 and 42.68 days during Oct-Nov, Nov-Dec and Dec-Jan, respectively. The lawa passed through 5 stadia and showed geometric increase in the width of the head capsule at each moult. The moths fed with honey produced an average of 129 eggs as compared to 20.6 eggs when raised on water alone. There was a significant increase in the pupal weight when reared on artificial diet than on cotton bolls for two consequent generations. Sex ratio of the moths reared on artificial diet was in consonance (60.3:29.7 and 53.3:46.7) with those reared on cotton bolls (50.8:49.2). The artificial diet proved to be suitable in rearing pink bollworm across two generations without affecting its fecundity. Among the different foods offered, significantly higher adult longevity was recorded on honey, followed by sugar syrup, fresh cotton flowers, water alone, and without food and wate

Flowering events in sorghum in relation to expression of resistance to sorghum midge, Stenodiplosis sorghicola

Sorghum midge (Stenodiplosis sorghicola Coquillett) is an important pest of grain sorghum, and host plant resistance is one of the most effective means of controlling this pest. Several studies have shown that resistance to sorghum midge is associated with short and tight glumes, faster rate of grain development, and tannins. However, some recent studies suggested that time of flowering is the principal component of resistance to sorghum midge. Therefore, we conducted a series of experiments under laboratory and field conditions on the flowering behaviour of a diverse array of midge-resistant and midge-susceptible genotypes to quantify the contribution of time of flowering in genotypic resistance to sorghum midge. Time of flowering under field and laboratory conditions did not show any differences between midge-resistant and midge-susceptible genotypes. Time to maximum flowering varied considerably between the rainy and the post-rainy seasons. Under field conditions, most of the spikelets in the midge-resistant lines opened between 0000 and 0400 h, while most of the spikelets in the susceptible check, CSH 1, opened at 0200 h. Under light and dark conditions in the laboratory, most of the spikelets opened at 0300 h in all genotypes, irrespective of their level of resistance to the sorghum midge. However, flowering events continued for a longer period under dark conditions outside the laboratory. There were no differences in oviposition in panicles on the midge-resistant genotype, ICSV 745, infested between 0200 and 0600 h, and significantly more eggs were laid in spikelets of the susceptible check, CSH 1, than in the midge-resistant, ICSV 745, at all infestation times. The peak oviposition was recorded at 0945 h irrespective of the level of resistance to sorghum midge, and significantly more eggs were laid in the spikelets of CSH 1 and Swarna than in ICSV 745 and ICSV 197. There was no evidence of change in the susceptibility of sorghum midge-resistant genotypes when infested at different times in relation to time of flowering. Therefore, flowering behaviour of sorghum genotypes seems to play little role in genotypic susceptibility to sorghum midge

Ssr-based molecular profiling of selected donors of wide compatibility, elongated uppermost internode, stigma exsertion and submergence tolerance traits and parental lines of commercial rice (o. Sativa l.) Hybrids

Molecular breeding plays an important role in sustainable agriculture development. Hybrid rice technology aims to increase the yield potential of rice beyond the level of inbred high-yielding varieties (HYVs) by exploiting the phenomenon of hybrid vigour or heterosis. Improvement of hybrid rice parental line is necessary to meet the food security problem. Parental polymorphism was carried with 215 SSR markers between five recurrents and ten donors. During the foreground selection, both reported markers (S5-Indel and BF-S5) were validated for wide compatibility, 2 out of 14 (ART5 and SC3) validates for submergence tolerance, one out of two (RM5) validate for stigma exsertion, whereas 2 of 3 markers (RM5970, RM3476) validated for elongated uppermost internode traits between recurrents and donors. For background selection, maximum polymorphic markers (112) between IR58025eB i.e improved maintainer line with elongated uppermost internode and Oryza meridionalis and minimum polymorphic markers (42) between IR79156B and IR91-1591-3 were found. Marker-assisted backcrossing accelerate, the transfer of gene of interest in desirable genetic background. Genotypes IR58025B and IR58025eB emerged as genetically most similar with a value of 97%. The genotypes IR64 Sub1 and Oryza meridionalis were found most divergent showing 33% genetic similarity. Dissimilarity coefficient of the generated information obtained on genetic relatedness would be supportive in further rice breeding program

Evaluation of very high- and very low-dose intravitreal aflibercept in patients with neovascular age-related macular degeneration.

PURPOSE: To determine bioactivity and duration of effect of intravitreal aflibercept injection (also known as vascular endothelial growth factor Trap-Eye) for neovascular age-related macular degeneration (AMD). METHODS: In this double-masked, phase 1 study, 28 patients with lesions ≤12 disc areas, ≥50% active choroidal neovascularization (CNV), and best corrected visual acuity (BCVA) ≤20/40 were randomized 1:1 to a single intravitreal injection of aflibercept 0.15 or 4 mg. The primary end point was the change from baseline in central retinal/lesion thickness (CR/LT) at week-8. Secondary outcomes were the change from baseline BCVA, the change in CNV lesion size and area of leakage, and proportion of patients requiring repeat injection at 8 weeks. RESULTS: Mean percent decrease in CR/LT for the 4-mg and 0.15-mg groups was, respectively, 34.2 versus 13.3 at week 4 (P=0.0065), 23.8 versus 5.9 at week 6 (P=0.0380), and 25.2% versus 11.3% at week 8 (P=0.150). The 4-mg group gained a mean of 4.5 letters in BCVA (6/14 patients gaining ≥10 letters) versus 1.1 letters in 0.15-mg group (1/14 gaining ≥10 letters) at week 8. Fewer patients needed retreatment in the 4-mg group at week 8. No serious adverse event or ocular inflammation was reported in either group. CONCLUSIONS: Intravitreal aflibercept 4 mg had a safety profile similar to that of the very low dose 0.15 mg, and was well-tolerated. The 4-mg dose significantly reduced foveal thickening at weeks 4 and 6, significantly improved BCVA at weeks 6, and reduced the need for repeat injection after 8 weeks compared with intravitreal aflibercept 0.15 mg in neovascular AMD patients

Microstructural evolution in solution heat treatment of gas- atomised Al alloy (7075) powder for cold spray

Cold gas dynamic spray is being explored as a repair technique for high-value metallic components, given its potential to produce pore and oxide-free deposits of between several micrometers and several millimeters thick with good levels of adhesion and mechanical strength. However, feedstock powders for cold spray experience rapid solidification if manufactured by gas atomization and hence can exhibit non-equilibrium microstructures and localized segregation of alloying elements. Here, we used sealed quartz tube solution heat treatment of a precipitation hardenable 7075 aluminum alloy feedstock to yield a consistent and homogeneous powder phase composition and microstructure prior to cold spraying, aiming for a more controllable heat treatment response of the cold spray deposits. It was shown that the dendritic microstructure and solute segregation in the gas-atomized powders were altered, such that the heat-treated powder exhibits a homogeneous distribution of solute atoms. Micro-indentation testing revealed that the heat-treated powder exhibited a mean hardness decrease of nearly 25% compared to the as received powder. Deformation of the powder particles was enhanced by heat treatment, resulting in an improved coating with higher thickness (* 300 lm compared to * 40 um for untreated feedstock). Improved particle–substrate bonding was evidenced by formation of jets at the particle boundaries

Rice biofortification: breeding and genomic approaches for genetic enhancement of grain zinc and iron contents

Rice is a highly consumed staple cereal cultivated predominantly in Asian countries, which share 90% of global rice production. Rice is a primary calorie provider for more than 3.5 billion people across the world. Preference and consumption of polished rice have increased manifold, which resulted in the loss of inherent nutrition. The prevalence of micronutrient deficiencies (Zn and Fe) are major human health challenges in the 21st century. Biofortification of staples is a sustainable approach to alleviating malnutrition. Globally, significant progress has been made in rice for enhancing grain Zn, Fe, and protein. To date, 37 biofortified Fe, Zn, Protein and Provitamin A rich rice varieties are available for commercial cultivation (16 from India and 21 from the rest of the world; Fe > 10 mg/kg, Zn > 24 mg/kg, protein > 10% in polished rice as India target while Zn > 28 mg/kg in polished rice as international target). However, understanding the micronutrient genetics, mechanisms of uptake, translocation, and bioavailability are the prime areas that need to be strengthened. The successful development of these lines through integrated-genomic technologies can accelerate deployment and scaling in future breeding programs to address the key challenges of malnutrition and hidden hunger

Inhibition of Protein Aggregation: Supramolecular Assemblies of Arginine Hold the Key

BACKGROUND: Aggregation of unfolded proteins occurs mainly through the exposed hydrophobic surfaces. Any mechanism of inhibition of this aggregation should explain the prevention of these hydrophobic interactions. Though arginine is prevalently used as an aggregation suppressor, its mechanism of action is not clearly understood. We propose a mechanism based on the hydrophobic interactions of arginine. METHODOLOGY: We have analyzed arginine solution for its hydrotropic effect by pyrene solubility and the presence of hydrophobic environment by 1-anilino-8-naphthalene sulfonic acid fluorescence. Mass spectroscopic analyses show that arginine forms molecular clusters in the gas phase and the cluster composition is dependent on the solution conditions. Light scattering studies indicate that arginine exists as clusters in solution. In the presence of arginine, the reverse phase chromatographic elution profile of Alzheimer's amyloid beta 1-42 (Abeta(1-42)) peptide is modified. Changes in the hydrodynamic volume of Abeta(1-42) in the presence of arginine measured by size exclusion chromatography show that arginine binds to Abeta(1-42). Arginine increases the solubility of Abeta(1-42) peptide in aqueous medium. It decreases the aggregation of Abeta(1-42) as observed by atomic force microscopy. CONCLUSIONS: Based on our experimental results we propose that molecular clusters of arginine in aqueous solutions display a hydrophobic surface by the alignment of its three methylene groups. The hydrophobic surfaces present on the proteins interact with the hydrophobic surface presented by the arginine clusters. The masking of hydrophobic surface inhibits protein-protein aggregation. This mechanism is also responsible for the hydrotropic effect of arginine on various compounds. It is also explained why other amino acids fail to inhibit the protein aggregation

Influence of non-nucleoside reverse transcriptase inhibitors (efavirenz and nevirapine) on the pharmacodynamic activity of gliclazide in animal models

<p>Abstract</p> <p>Background</p> <p>Type 2 diabetes may occur as a result of HIV infection and/or its treatment. Gliclazide is a widely used drug for the treatment of type 2 diabetes. Efavirenz and nevirapine are widely used non-nucleoside reverse transcriptase inhibitors for the treatment of HIV infection. The role of Efavirenz and nevirapine on the pharmacodynamic activity of gliclazide is not currently known. The objective of this study was to examine the effect of oral administration of efavirenz and nevirapine on blood glucose and investigate their effect on the activity of gliclazide in rats (normal and diabetic) and rabbits to evaluate the safety and effectiveness of the combination.</p> <p>Methods</p> <p>Studies in normal and alloxan induced diabetic rats were conducted with oral doses of 2 mg/kg bd. wt. of gliclazide, 54 mg/kg bd. wt. of efavirenz or 18 mg/kg bd. wt. of nevirapine and their combination with adequate washout periods in between treatments. Studies in normal rabbits were conducted with 5.6 mg/1.5 kg bd. wt. of gliclazide, 42 mg/1.5 kg bd. wt. of efavirenz or 14 mg/1.5 kg bd. wt. of nevirapine and their combination given orally. Blood samples were collected at regular time intervals in rats from retro orbital puncture and by marginal ear vein puncture in rabbits. All the blood samples were analysed for blood glucose by GOD/POD method.</p> <p>Results</p> <p>Efavirenz and nevirapine alone have no significant effect on the blood glucose level in rats and rabbits. Gliclazide produced hypoglycaemic/antidiabetic activity in normal and diabetic rats with peak activity at 2 h and 8 h and hypoglycaemic activity in normal rabbits at 3 h. In combination, efavirenz reduced the effect of gliclazide in rats and rabbits, and the reduction was more significant with the single dose administration of efavirenz than multiple dose administration. In combination, nevirapine has no effect on the activity of gliclazide in rats and rabbits.</p> <p>Conclusion</p> <p>Thus, it can be concluded that the combination of efavirenz and gliclazide may need dose adjustment and care should be taken when the combination is prescribed for their clinical benefit in diabetic patients. The combination of nevirapine and gliclazide was safe. However, further studies are warranted.</p