Comparative Growth Rate of Cyanobacteria from “Usar” Soil (saline/alkaline soils) with Respect to Pigments

The pigment content in Blue-green algae is a specific feature of each species. The pigment variation is specific features among microalgae. The paper aim to analyze cyanobacterial extracts of different Usar soil of Azamgarh and Varanasi, Uttar Pradesh. The main object here is the importance of the blue green algae especially because of the pigments present in this class of algae. Pigments from natural sources are gaining more importance mainly due to health and environmental issues. Algae contain a wide range of pigments. Three major classes of pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins (Phycocyanin and phycoerythrin). Our present study investigates the efficiency for phycobiliprotein pigment production from four different cyanobacteria Hapalosiphon sp., Phormidium sp., Anabaena sp. and Nostoc sp. The harvested and dried biomass was subjected to extract pigments using different solvents. Thin Layer Chromatography was performed from extracted pigments using Acetone as extraction solvents. And running solvent especially for phycocyanin pigment was optimized and concluded that Petroleum ether and Acetone in the ratio of 7:3. This paper presents the information about the natural pigments of cyanobacteria and how they can be extracted and identified using different procedures and spectrophotometry. It emphasizes that the principal algal pigments are Phycobilins, Chlorophylls and Carotenoids.

Contribution of opsins and chromophores to cone pigment variation across populations of Lake Victoria cichlids

Adaptation to heterogeneous sensory environments has been implicated as a key parameter in speciation. Cichlid fish are a textbook example of divergent visual adaptation, mediated by variation in the sequences and expression levels of cone opsin genes (encoding the protein component of visual pigments). In some vertebrates including fish, visual sensitivity is also tuned by the ratio of Vitamin A1/A2-derived chromophores (i.e. the light-sensitive component of the visual pigment, bound to the opsin protein), where higher proportions of A2 cause a more red-shifted wavelength absorbance. Here, we explore variation in chromophore ratios across multiple cichlid populations in Lake Victoria, using as a proxy the enzyme CYP27C1 that catalyses the conversion of Vitamin A1- into A2. We focus on sympatric Pundamilia cichlids, where species with blue or red male coloration co-occur at multiple islands, but occupy different depths and consequently different visual habitats. In the red species, we found higher cyp27c1 expression in populations from turbid-water than from clear-water locations, but there was no such pattern in the blue species. Across populations, differences between the sympatric species in cyp27c1 expression had a consistent relationship with species differences in opsin expression patterns, but the red/blue identity reversed between clear- and turbid-water locations. To assess the contribution of heritable versus environmental causes of variation, we tested whether light manipulations induce a change in cyp27c1 expression in the laboratory. We found that cyp27c1 expression was not influenced by experimental light conditions, suggesting that the observed variation in the wild is due to genetic differences. Establishing the biological importance of this variation requires testing the link between cyp27c1 expression and A1/A2 ratios in the eye, as well as its consequences for visual performance.

A nonsense mutation in TFEC is the likely cause of the recessive piebald phenotype in ball pythons (Python regius)

Captive-bred ball pythons (Python regius) represent a powerful model system for studying the genetic basis of colour variation and Mendelian phenotypes in vertebrates. Although hundreds of Mendelian phenotypes (colour morphs) affecting colouration and patterning have been described for ball pythons, the genes causing these colour morphs remain unknown. Here, we used crowdsourcing of samples from commercial ball python breeders to investigate the genetic basis of a classic phenotype found in the pet trade, the piebald [characterized by dorsolateral patches of unpigmented (white) skin]. We used whole-genome sequencing of pooled samples followed by population genetic methods to delineate the genomic region containing the causal gene. We identified TFEC of the MIT-family of transcription factors as a candidate gene. Functional annotation of SNPs identified a nonsense mutation in TFEC, which we conclude is the likely causal variant for the piebald phenotype. Our work shows that ball python colour morphs have the potential to be an excellent model system for studying the genetic basis of pigment variation in vertebrates, and highlights how collaborations with commercial breeders can accelerate discoveries.

Genetic Analysis of Walnut (Juglans regia L.) Pellicle Pigment Variation Through a Novel, High-Throughput Phenotyping Platform

Walnut pellicle color is a key quality attribute that drives consumer preference and walnut sales. For the first time a high-throughput, computer vision-based phenotyping platform using a custom algorithm to quantitatively score each walnut pellicle in L* a* b* color space was deployed at large-scale. This was compared to traditional qualitative scoring by eye and was used to dissect the genetics of pellicle pigmentation. Progeny from both a bi-parental population of 168 trees (‘Chandler’ × ‘Idaho’) and a genome-wide association (GWAS) with 528 trees of the UC Davis Walnut Improvement Program were analyzed. Color phenotypes were found to have overlapping regions in the ‘Chandler’ genetic map on Chr01 suggesting complex genetic control. In the GWAS population, multiple, small effect QTL across Chr01, Chr07, Chr08, Chr09, Chr10, Chr12 and Chr13 were discovered. Marker trait associations were co-localized with QTL mapping on Chr01, Chr10, Chr14, and Chr16. Putative candidate genes controlling walnut pellicle pigmentation were postulated.

An antioxidant function for dimethylsulfonopropionate (DMSP) and dimethylsulfoxide (DMSO) within three different phytoplankton groups

<p>Dimethylsulfonopropionate (DMSP) and dimethylsulfoxide (DMSO) are two compounds involved in the carbon and sulfur cycle and are the precursors of the climate cooling gas dimethylsulfide (DMS). Despite decades of research, their role as osmoregulator, cryoprotector or antioxidant within the phytoplankton cells remains uncertain in some part. Since the antioxidant cascade system from the DMSP reported by Sunda & al. (2002), more investigation need to be conducted to confirm or accurate these interactions. This study aims to improve the knowledge about DMSP and DMSO and their hypothetic role of antioxidant on three different classes of phytoplankton (Dinophyceae – Prymnesiophyceae – diatom) and one diatom no-DMSP producer Chaetoceros sp. as negative control. Laboratory cultures were submitted to three oxidative stress to produce Reactive Oxygen Species (ROS) with (1) increasing light intensity from 100 to 600 and up to 1200 µmole/m²s for a global and natural oxidative stress; (2) using the menadone bisulfite (MSB) to generate ·O<sub>2</sub> and (3) using 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) to inhibit the photosystem II (PSII). The PSII activity, the Chlorophyll a concentration (Chl a), the lipidic peroxidation (LOP), the ROS production and the pigment variation were analysed after 6h of incubation and related to the evolution of the DMSP and DMSO concentrations to better understand the cellular oxidative stress and its impact on the phytoplankton cell and DMSP and DMSO production.</p>

Alteration of photosynthetic pigments and antioxidant systems in tomato under drought with Tebuconazole and Hexaconazole applications

Present investigation was focused on the response and regulation of the antioxidant defense system and photosynthetic pigment variation effect of two important fungicides or plant growth regulators Hexaconazole (HEX) and Tebuconazole (TBZ) on drought stressed tomato (Lycopersicon esculentum Mill.) plants. Drought stress was imposed for 30 Days after sowing (DAS) of tomato plant. The water was irrigated by 4 Days Interval Drought (DID) and the control plants were regularly irrigated. Triazole treatment like HEX at 15 mg L-1 and TBZ at 10 mg L-1 imposed on 30, 40 and 50 DAS. The plant samples were collected on 40, 50 and 60 DAS. The photosynthetic pigments like chlorophyll – a, chlorophyll – b and total chlorophyll were estimated. The drought stress reduced the photosynthetic pigments and increased the antioxidant contents and antioxidant enzymes activities. The combined drought stress with triazole treatments increased the photosynthetic pigments then reduced the ascorbic acid (AA), α-tocopherol, catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) activities, when compared to drought stressed plants. It can be concluded that the triazole treatment partially mitigated the adverse effects of drought stress in L. esculentum.