Effect of post flowering foliar sprays of nutrients on fruit growth of kokum (Garcinia indica Choisy)

A study was undertaken at Dapoli (Maharashtra) to find out the effect of application of postflowering foliar nutrients on growth of kokum (Garcinia indica Choisy) fruits. Various concentrations and combinations of urea 1.0%, potassium nitrate 3.0%, monopotassium phosphate 0.5% and 19 N:19 P:19 K (1.0%) were applied at fruit set and repeated 20 days after fruit (DAF) set. The results indicated that weight of fruit increased consistently up to 90 days of fruit set and decreased slightly at harvest irrespective of treatments. The increase in fruit length and fruit circumference was linear till harvest. All foliar nutrient treatments improved the growth rate over control with respect to fruit weight, fruit length and fruit circumference at all stages of fruit growth. T4 [potassium nitrate 3.0% twice], T5 [potassium nitrate 3.0% + monopotassium phosphate 0.5%] and T6 [19 N: 19 P:19 K (1.0%) twice] were at par with each other and recorded significantly higher yield over control. Among the treatments T2 [Urea 1.0% + potassium nitrate 3.0%] was the best for improvement in fruit weight and fruit circumference of kokum fruit. All foliar nutrient sprays improved the quality of kokum fruit with respect to total soluble solids, acidity, ascorbic acid and sugar content. Among the treatments, T4 and T5 were at par with each other and significantly improved acidity and sugar content. &nbsp

Effect of post flowering foliar sprays of nutrients on fruit growth of kokum (Garcinia indica Choisy)

A study was undertaken at Dapoli (Maharashtra) to find out the effect of application of postflowering foliar nutrients on growth of kokum (Garcinia indica Choisy) fruits. Various concentrations and combinations of urea 1.0%, potassium nitrate 3.0%, monopotassium phosphate 0.5% and 19 N:19 P:19 K (1.0%) were applied at fruit set and repeated 20 days after fruit (DAF) set. The results indicated that weight of fruit increased consistently up to 90 days of fruit set and decreased slightly at harvest irrespective of treatments. The increase in fruit length and fruit circumference was linear till harvest. All foliar nutrient treatments improved the growth rate over control with respect to fruit weight, fruit length and fruit circumference at all stages of fruit growth. T4 [potassium nitrate 3.0% twice], T5 [potassium nitrate 3.0% + monopotassium phosphate 0.5%] and T6 [19 N: 19 P:19 K (1.0%) twice] were at par with each other and recorded significantly higher yield over control. Among the treatments T2 [Urea 1.0% + potassium nitrate 3.0%] was the best for improvement in fruit weight and fruit circumference of kokum fruit. All foliar nutrient sprays improved the quality of kokum fruit with respect to total soluble solids, acidity, ascorbic acid and sugar content. Among the treatments, T4 and T5 were at par with each other and significantly improved acidity and sugar content. &nbsp

Design and implementation of an instrumented pedal for cycling biomechanics research

Cycling is a common, low-impact activity used for recreation, exercise, and rehabilitation. Knee joint loading can be predicted using inverse dynamic analyses of pedal load cell and kinematic data measured during cycling biomechanics experiments. Several studies have successfully measured foot loading at the pedals, e.g. by using custom instrumented pedal spindles outfitted with strain gauges and a potentiometer to measure crank angle [1-3]. Such designs are relatively complex, requiring difficult machining and component fabrication, and require post-processing of strain gauge data. The long-term goal of this study is to calculate knee joint loading and, ultimately, cartilage tissue stress to provide evidence-based prescriptions for rehabilitative and fitness sustainment exercises for those who are at high risk for knee osteoarthritis. The objective of this project was to design, fabricate, and implement an instrumented pedal system using existing load cells for use in cycling biomechanics research. Measured data retrieved from the load cells during cycling experiments will be compared to similar studies to verify that this project was successful

Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles. Identification of the crucial role of a threonine residue for enzyme activity

Volatile esters, a major class of compounds contributing to the aroma of many fruit, are synthesized by alcohol acyl-transferases (AAT). We demonstrate here that, in Charentais melon (Cucumis melo var. cantalupensis), AAT are encoded by a gene family of at least four members with amino acid identity ranging from 84% (Cm-AAT1/Cm-AAT2) and 58% (Cm-AAT1/Cm-AAT3) to only 22% (Cm-AAT1/Cm-AAT4). All encoded proteins, except Cm-AAT2, were enzymatically active upon expression in yeast and show differential substrate preferences. Cm-AAT1 protein produces a wide range of short and long-chain acyl esters but has strong preference for the formation of E-2-hexenyl acetate and hexyl hexanoate. Cm-AAT3 also accepts a wide range of substrates but with very strong preference for producing benzyl acetate. Cm-AAT4 is almost exclusively devoted to the formation of acetates, with strong preference for cinnamoyl acetate. Site directed mutagenesis demonstrated that the failure of Cm-AAT2 to produce volatile esters is related to the presence of a 268-alanine residue instead of threonine as in all active AAT proteins. Mutating 268-A into 268-T of Cm-AAT2 restored enzyme activity, while mutating 268-T into 268-A abolished activity of Cm-AAT1. Activities of all three proteins measured with the prefered substrates sharply increase during fruit ripening. The expression of all Cm-AAT genes is up-regulated during ripening and inhibited in antisense ACC oxidase melons and in fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. The data presented in this work suggest that the multiplicity of AAT genes accounts for the great diversity of esters formed in melon

Wall teichoic acid structure governs horizontal gene transfer between major bacterial pathogens

Mobile genetic elements (MGEs) encoding virulence and resistance genes are widespread in bacterial pathogens, but it has remained unclear how they occasionally jump to new host species. Staphylococcus aureus clones exchange MGEs such as S. aureus pathogenicity islands (SaPIs) with high frequency via helper phages. Here we report that the S. aureus ST395 lineage is refractory to horizontal gene transfer (HGT) with typical S. aureus but exchanges SaPIs with other species and genera including Staphylococcus epidermidis and Listeria monocytogenes. ST395 produces an unusual wall teichoic acid (WTA) resembling that of its HGT partner species. Notably, distantly related bacterial species and genera undergo efficient HGT with typical S. aureus upon ectopic expression of S. aureus WTA. Combined with genomic analyses, these results indicate that a ‘glycocode’ of WTA structures and WTA-binding helper phages permits HGT even across long phylogenetic distances thereby shaping the evolution of Gram-positive pathogens

Mechanism of gallic acid biosynthesis in bacteria (Escherichia coli) and walnut (Juglans regia)

Gallic acid (GA), a key intermediate in the synthesis of plant hydrolysable tannins, is also a primary anti-inflammatory, cardio-protective agent found in wine, tea, and cocoa. In this publication, we reveal the identity of a gene and encoded protein essential for GA synthesis. Although it has long been recognized that plants, bacteria, and fungi synthesize and accumulate GA, the pathway leading to its synthesis was largely unknown. Here we provide evidence that shikimate dehydrogenase (SDH), a shikimate pathway enzyme essential for aromatic amino acid synthesis, is also required for GA production. Escherichia coli (E. coli) aroE mutants lacking a functional SDH can be complemented with the plant enzyme such that they grew on media lacking aromatic amino acids and produced GA in vitro. Transgenic Nicotianatabacum lines expressing a Juglans regia SDH exhibited a 500% increase in GA accumulation. The J. regia and E. coli SDH was purified via overexpression in E. coli and used to measure substrate and cofactor kinetics, following reduction of NADP+ to NADPH. Reversed-phase liquid chromatography coupled to electrospray mass spectrometry (RP-LC/ESI–MS) was used to quantify and validate GA production through dehydrogenation of 3-dehydroshikimate (3-DHS) by purified E. coli and J. regia SDH when shikimic acid (SA) or 3-DHS were used as substrates and NADP+ as cofactor. Finally, we show that purified E. coli and J. regia SDH produced GA in vitro