Physiochemical response of papaya genotypes exposed to low temperature regimes

Susceptibility to low temperature stress is the major threat to papaya cultivation. Here, we studied a low temperature stress tolerance in papaya plant. We have investigated the effect of different low temperature regimes, 28°/18°C (day/night) to 16°/06°C (day/night) with a gradual decrease of 2°C on every two days and one set with direct exposure to the low temperature of 18°/08°C (day/night), called the acclimatized plant, in five diverse papaya genotypes (Pusa Nanha, Red Lady P-7-2, P-7-9, and P-7-14) and cold tolerant wild relative of cultivated papaya genotype (Vasconcellea cundinamarcensis V.M. Badillo) under controlled regulated conditions. It was observed that there were significant variations in the physiological and biochemical parameters like photosynthetic gas exchange parameters, chlorophyll content, fluorescence parameters, relative water content (RWC), membrane stability index (MSI), total sugars content, total soluble proteins content, lipid peroxidation, and proline accumulation in leaf tissues. Maximum stomatal conductance, chlorophyll fluorescence, RWC, MSI, total sugars, total soluble proteins, proline and lowest MDA contents were observed in Vasconcellea cundinamarcensis followed by inbred P-7-9 as compared to other genotypes under low temperature stress. Among all the papaya genotypes, P-7-9 showed more adaptability to low temperature stress and it further give new insights for developing low temperature tolerant papaya genotypes, especially under changing climate situations.

Pattern of Ear Diseases in the Patients Attending Ear Outpatient Department of a Tertiary Center in Eastern Nepal.

Introduction: The prevalence of disabling hearing loss for adults and children is greatest in South Asia followed by Asia Pacific and Sub-Saharan Africa. Nepal is one of the least developed nation where hearing loss and ear diseases is very common. Objective: To find out the pattern of ear diseases in the patients attending Ear outpatient department (OPD) of Biratnagar Eye Hospital. Materials and Methods: A retrospective, descriptive review of data retrieved from the medical record section of the Hospital between January 1, 2014 to December 31, 2014 was done. The data were tabulated and analysed. The results are expressed in number and percentage. Results: Chronic suppurative otitis media, mucosal (42.64%) and ear wax/otomycosis (24.39%) were the commonest ear diseases found. Eustachian tube dysfunction (12.89%), acute otitis media (0.74%), acute suppurative otitis media (2.9%), otitis media with effusion (0.54%) were other common diseases. Presbyacusis (10.09%) was found to be a common problem in adults. Various other external auditory canal problems and those of inner ear were also detected. Conclusions: Ear diseases are one of the major health problems in Nepal. This study has found chronic otitis media and ear wax/otomycosis to be commonest problems in children and adults attending the Ear OPD of Biratnagar eye hospital.

Evaluation of analgesic activity of Emblica officinalis in albino rats.

Background: Amla is one of the most often used herbs in indigenous medicine, whose all parts including fruit, seed, leaves, root, bark, and fl owers are used in various Ayurvedic/Unani medicines. However, studies to establish analgesic potential of amla were limited, so the purpose of the present study was to evaluate analgesic activity of amla, if it possesses any. Methods: Albino rats were divided randomly in three groups of six rats each. Group 1 (control) received distilled water orally, Group 2 (test) received Emblica offi cinalis extract in dose of 600 mg/kg orally and Group 3 (standard) received Pentazocine in dose 10 mg/kg intraperitoneally. Results: Emblica offi cinalis extract did not produced statistically signifi cant (p>0.05) analgesia when compared with the control group in hot plate latency, but produced a statistically signifi cant reduction in 6% NaCl induced abdominal writhing (p<0.05). Conclusions: Since the plant extract signifi cantly reduced the number of writhes in abdominal writhing model, but do not increase hot plate latency, the commercially available crude extract of Emblica offi cinalis exhibit analgesic activity involving peripheral mechanisms.

Denaturing gradient gel electrophoresis profiling of bacterial communities composition in Arabian Sea.

Denaturing gradient gel electrophoresis (DGGE) was used to elucidate spatial and temporal variations in bacterial community composition (BCC) from four locations along the central west coast of India. DNA extracts from 36 water samples collected from surface, mid-depth (~10 m) and close to bottom (~20 m) during premonsoon, postmonsoon, monsoon were analyzed by PCR for amplifying variable region of 16S rRNA gene and subsequently through DGGE. Prominent bands were excised, cloned and sequenced indicated the preponderance of gammaproteobacteria, bacteroidetes and cyanobacteria. Non-metric dimensional scaling of the DGGE gels indicated that the spatial variations in BCC were prominent among the sampling locations. Temporal variations in the BCC appear to be influenced by monsoonal processes. The canonical correspondence analyses suggest that the concentration of chlorophyll a and nitrate are two important environmental factors for both spatial and temporal variations in BCC. Chlorophyll a seems to be impart a top-down control of BCC while nitrate, the bottom-up control. Our results also suggest that BCC can vary over a small geographic distance in highly dynamic, seasonally predisposed tropical coastal waters.

An insight into the sequential, structural and phylogenetic properties of banana 1-aminocyclopropane-1-carboxylate synthase 1 and study of its interaction with pyridoxal-5'-phosphate and aminoethoxyvinylglycine.

In banana, ethylene production for ripening is accompanied by a dramatic increase in 1-aminocyclopropane-1- carboxylate (ACC) content, transcript level of Musa acuminata ACC synthase 1 (MA-ACS1) and the enzymatic activity of ACC synthase 1 at the onset of the climacteric period. MA-ACS1 catalyses the conversion of S-adenosyl- L-methionine (SAM) to ACC, the key regulatory step in ethylene biosynthesis. Multiple sequence alignments of 1- aminocyclopropane-1-carboxylate synthase (ACS) amino acid sequences based on database searches have indicated that MA-ACS1 is a highly conserved protein across the plant kingdom. This report describes an in silico analysis to provide the fi rst important insightful information about the sequential, structural and phylogenetic characteristics of MA-ACS1. The three-dimensional structure of MA-ACS1, constructed based on homology modelling, in combination with the available data enabled a comparative mechanistic analysis of MA-ACS1 to explain the catalytic roles of the conserved and non-conserved active site residues. We have further demonstrated that, as in apple and tomato, banana- ACS1 (MA-ACS1) forms a homodimer and a complex with cofactor pyridoxal-5′-phosphate (PLP) and inhibitor aminoethoxyvinylglycine (AVG). We have also predicted that the residues from the PLP-binding pocket, essential for ligand binding, are mostly conserved across the MA-ACS1 structure and the competitive inhibitor AVG binds at a location adjacent to PLP.