Reproductive performance of four aphidophagous ladybirds on cowpea aphid, Aphis craccivora Koch

Abstract:  This study investigated prey consumption, egg production, percent progeny loss, reproductive, pre- and post-reproductive periods, reproductive time ratio, reproductive rate and bioconversion efficiency of four aphidophagous ladybirds, viz. Cheilomenes sexmaculata (Fabricius), Coccinella septempunctata Linnaeus, Coccinella transversalis Fabricius and Propylea dissecta (Mulsant) on Dolichos lablab Linnaeus infested with cowpea aphid, Aphis craccivora Koch. C. sexmaculata had the highest bioconversion efficiency, reproductive rate and reproductive time ratio followed in rank order by P. dissecta , C. transversalis and C. septempunctata . This study indicates that C. sexmaculata has a narrow ecological relationship with A. craccivora . The increased allocation of resources to reproduction as indicated through a high reproductive time ratio and high bioconversion efficiency of C. sexmaculata and P. dissecta suggest that they may be better adapted to compete for this prey with larger species like C. transversalis and C. septempunctata .     

Phosphate solubilization and growth promotion by <Emphasis Type="Italic">Pseudomonas fragi</Emphasis> CS11RH1 (MTCC 8984), a psychrotolerant bacterium isolated from a high altitude Himalayan rhizosphere

Phosphate solubilization and growth promotion by Pseudomonas fragi CS11RH1 (MTCC 8984), a psychrotolerant bacterium isolated from a high altitude garlic rhizosphere from the Indian Himalayas, are reported here. The identity of the isolate was arrived on the basis of its biochemical features and sequencing of the 16S rRNA gene. The isolate grew and solubilized phosphate at temperatures ranging from 4 to 30°C. Besides solubilizing P it produced indole acetic acid (IAA) and hydrogen cyanide (HCN). Seed bacterization with the isolate significantly increased the percent germination, rate of germination, plant biomass and nutrient uptake of wheat seedlings. While Pseudomonas fragi is normally associated with the spoilage of dairy products stored at cold temperatures, this is an early report on the plant growth promoting ability of the bacterium.     

Phylogenetic Study of Methanol Oxidizers from Chilika-Lake Sediments Using Genomic and Metagenomic Approaches

Group-wise diversity of sediment methylotrophs of Chilika lake (Lat. 19°28′–19°54′N; Long. 85°06′–85°35′E) Odisha, India at various identified sites was studied. Both the culturable and unculturable (metagenome) methylotrophs were investigated in the lake sediments employing both mxaF and 16S rRNA genes as markers. ARDRA profiling, 16S rRNA gene sequencing, PAGE profiling of HaeIII, EcoRI restricted mxaF gene and the mxaF gene sequences using culture-dependent approach revealed the relatedness of α-proteobacteria and Methylobacterium, Hyphomicrobium and Ancyclobacter sp. The total viable counts of the culturable aerobic methylotrophs were relatively higher in sediments near the sea mouth (S3; Panaspada), also demonstrated relatively high salinity (0.1 M NaCl) tolerance. Metagenomic DNA from the sediments, amplified using GC clamp mxaF primers and resolved through DGGE, revealed the diversity within the unculturable methylotrophic bacterium Methylobacterium organophilum, Ancyclobacter aquaticus, Burkholderiales and Hyphomicrobium sp. Culture-independent analyses revealed that up to 90 % of the methylotrophs were unculturable. The study enhances the general understandings of the metagenomic methylotrophs from such a special ecological niche.

Electronic supplementary material

The online version of this article (doi:10.1007/s12088-015-0510-3) contains supplementary material, which is available to authorized users.     

Microprojectile bombardment mediated genetic transformation of embryo axes and plant regeneration in cumin (<Emphasis Type="Italic">Cuminum cyminum</Emphasis> L.)

Pre-cultured cumin embryos were bombarded under 27 inches Hg vacuum, 25 mm distance from rupture disc to macrocarrier, 10 mm macrocarrier flight distance using 1100 psi rupture disc and 9 cm microprojectile travel distance. An average of 110 embryos was used per shot and 91% embryos showed transient GUS expression after 24 h. Shoot tips and roots of T₀ plantlets exhibited GUS expression done after 3 months of bombardment. Transformation was confirmed with PCR amplification of 0.96 and 1.3 kb band of hptII and gus genes respectively from T₀ transgenics and southern blot analysis using PCR amplified DIG labeled hptII gene as probe. It is the first successful attempt of transformation of cumin plant through direct gene transfer using particle gene gun and adequately exhibiting the possibility of stable transformation in cumin.     

A study of oxidative stress in cervical cancer- an institutional study

Cervical cancer is the second most common cause of cancer-related death among women worldwide, especially in developing countries. Oxidative stress has been associated with cervical cancer. Many studies demonstrated that the low level of antioxidants induces the production of free radicals that cause lipid peroxidation, DNA, and protein damage leading to mutations that favors malignant transformation. This is a case-control institutional study conducted to evaluate the level of oxidative stress in cervical cancer patients and the age-matched healthy controls. We measured level of TBARS expressed as MDA, activity of SOD and GSH level by the spectrophotometric method, and level of 8-OHdG was estimated using a competitive sandwich ELISA assay. Our results showed a significant increase in the level of lipid peroxidation in group IV when compared to the control, group II and group III (p < 0.001). The activity of SOD was also significantly higher in group IV when compared to the control group (p < 0.001), group II (p < 0.001), and group III (p < 0.001). The level of GSH was also significantly lower in group IV when compared to the control group (p < 0.01), group II (p < 0.01), and group III (p < 0.01). The level of 8-OHdG was significantly higher in group IV than in the other groups (p < 0.01). The results suggest that oxidative stress is involved in the pathogenesis of cervical cancer, which is demonstrated by an increased level of lipid peroxidation and higher levels of 8-OHdG and an altered antioxidant defense system.     

Effect of freezing and freeze-drying on the viability and storage of Lilium longiflorum L. and Zea mays L. pollen

The freeze-preservation of pollen is dependent on the interaction of several factors such as freezing rate, thawing rate, freeze-drying temperature and duration, storage temperature and environment and rehydration rates. Changes in any of these variables affects the others directly or indirectly.Rapid freezing of pollen at rates of approximately 200 °C/min maintains the highest degree of viable pollen in combination with rapid thawing rates of 218 °C/min. Rapid cooling and slow rewarming resulted in a substantial loss of pollen viability. This might indicate that intracellular ice crystals formed during rapid cooling perhaps grow into larger ice masses during slow rewarming or storage at temperatures above ?50 °C.The germinability of pollen freeze-dried at temperatures below ?50 °C was also prolonged over that of the controls. Germination values for unfrozen pollen stored for 30 days at 0–5 °C averaged 50% for lily and 20% for corn. Freeze-dried pollen stored for 30 days at the same temperature yielded considerably higher viability percentages for both lily and corn pollen. Drying time is an important factor, perhaps indicating that residual moisture is critical. Freeze-dried pollen can be stored at higher temperatures than frozen and control pollen. Freeze-dried material stored for five months at 0–5 °C, upon slow rehydration yielded intact grains which has average germination percentages of 25 for lily and 15 for corn. The same pollen upon rapid rehydration showed rupturing of 20–40% of the cells and practically no germination.     

Peroxiredoxins: a less studied component of hydrogen peroxide detoxification in photosynthetic organisms

Peroxiredoxins (Prx) are ubiquitous thiol-dependent peroxidases capable of reducing a broad range of toxic peroxides and peroxinitrites. A cysteinyl residue of peroxiredoxins reacts with the peroxides as primary catalytic center and oxidizes to sulfenic acid. The regeneration of the reduced form of Prx is required as a next step to allow its entry into next catalytic cycle. Several proteins, such as thioredoxin, glutaredoxin, cyclophilin, among others, are known to facilitate the regeneration of the reduced (catalytically active) form of Prx in plants. Based on the cysteine residues conserved in the deduced amino acid sequence and their catalytic mechanisms, four groups of peroxiredoxins have been distinguished in plants, namely, 1-Cys Prx, 2-Cys Prx, Type II Prx and Prx Q. Peroxiredoxins are known to play an important role in combating the reactive oxygen species generated at the level of electron transport activities in the plant exposed to different types of biotic and abiotic stresses. In addition to their role in antioxidant defense mechanisms in plants, they also modulate redox signaling during development and adaptation. Besides these general properties, peroxiredoxins have been shown to protect DNA from damage in vitro and in vivo. They also regulate metabolism in thylakoids and mitochondria. The present review summarizes the most updated information on the structure and catalysis of Prx and their functional importance in plant metabolism.     

Sequence analysis of UTR and coding region of kappa-casein gene of Indian riverine buffalo (Bubalus bubalis).

In this study, complete nucleotide as well as derived amino acid sequence characterization of water buffalo (Bubalus bubalis) kappa-casein gene has been presented. Kappa-casein cDNA clones were identified and isolated from a buffalo lactating mammary gland cDNA library. Sequence analysis of kappa-casein cDNA revealed 850 nucleotides with an open reading frame (ORF) of 573 nucleotides, encoding mature peptide of 169 amino acids. The 5' untranslated region (UTR) comprised 71 nucleotides, while 3' UTR was of 206 nucleotides. A total of 11 nucleotide and seven amino acid changes were observed in, buffalo (Bubalus bubalis) as compared to cattle (Bos taurus), sheep (Ovis aries) and goat (Capra hircus). Among these nucleotide changes, eight were unique in buffalo as they were fully conserved in cattle, sheep and goat. Majority of the nucleotide changes and all the amino acid changes; 14 (Asp-Glu), 19(Asp/Ser-Asn), 96(Ala-Thr), 126(Ala-Val), 128(Ala/Gly-Val), 156(Ala/Pro-Val) and 168(Ala/Glu-Val) were limited to exon IV. Three glycosylation sites, Thr 131, Thr 133 and Thr 142 reported in cattle and goat kappa-casein gene were also conserved in buffalo, however, in sheep Thr 142 was replaced by Ala. Chymosin hydrolysis site, between amino acids Phe 105 and Met 106, important for rennet coagulation process, were found to be conserved across four bovid species. Buffalo kappa-casein with the presence of amino acids Thr 136 and Ala 148 seems to be an intermediate of "A" and "B" variants of cattle. Comparison with other livestock species revealed buffalo kappa-casein sharing maximum nucleotide (95.5%) and amino acid (92.6%) similarity with cattle, whereas with pig it showed least sequence similarity of 76.0% and 53.2%, respectively. Phylogenetic analysis based on both nucleotide and amino acid sequence indicated buffalo kappa-casein grouping with cattle, while sheep and goat forming a separate cluster close to them. The non-ruminant species viz. camel, horse and pig were distantly placed, in separate lineages.