Influence of Media Gelling Agents on Root Biomass and in Vitro Va-mycorrfflzal Symbiosis of Carrot with Gigaspora Margarita

An in vitro study with Ri-TDNA transformed roots of carrot (Daucus carota) was carried out to evaluate the role of macro-elements contributed as impurities in the gelling agent (phytagel) over and above those present in the minimal (M) medium. Production of root biomass was taken as a measure to quantify the influence of macro-elements added to the minimal medium. The levels of phosphorus when adjusted to 1.19 mg/1 and 1.09 mg/l, lead to dry root biomass production at par with the control. Attempts made to lower the amount of impurities in phytagel by de-ionization using different alkalies, proved NaOH to give the best results in terms of relatively high amount of root biomass. In an in vitro dual culture system with carrot as host and Gigaspora margarita as the vesicular-arbuscular mycorrhizal fungus, phytagel impurities helped to produce maximum number of infection units and auxiliary cells when phytagel was added to the minimal medium

A novel in vitro whole plant system for analysis of polyphenolics and their antioxidant potential in cultivars of Ocimum basilicum

Plants are an important source for medicinal compounds. Chemical screening and selection is critical for identification of compounds of interest. Ocimum basilicum (Basil) is a rich source of polyphenolics and exhibits high diversity, therefore bioprospecting of a suitable cultivar is a necessity. This study reports on the development of a true to type novel "in vitro system" and its comparison with a conventional system for screening and selection of cultivars for high total phenolics, individual polyphenolics, and antioxidant content. We have shown for the first time using online acidic potassium permanganate chemiluminescence that extracts from Ocimum basilicum showed antioxidant potential. The current study identified the cultivar specific composition of polyphenolics and their antioxidant properties. Further, a distinct relationship between plant morphotype and polyphenolic content was also found. Of the 15 cultivars examined, "Holy Green", "Red Rubin", and "Basil Genovese" were identified as high polyphenolic producing cultivars while "Subja" was determined to be a low producer. The "in vitro system" enabled differentiation of the cultivars in their morphology, polyphenolic content, and antioxidant activity and is a cheap and efficient method for bioprospecting studies

In vitro and in situ screening systems for morphological and phytochemical analysis of Withania somnifera germplasms

We report, for the first time for Withania somnifera, the use of a modified in vitro system for morphological and phytochemical screening of true to type plants as compared with those grown in a conventional in situ system. Eleven germplasms of cultivated W. somnifera from different regions of India were collected to examine chemotypic variation in withaferin A (WA). Methods were developed to optimize WA extraction. The maximum concentration of WA was extracted from manually ground leaf and root material to which 60 % methanol was added followed by sonication in a water bath sonicator. Variation in WA concentration in whole plants was observed amongst the different germplasms. In the in vitro system, the concentration of WA ranged between 0.27 and 7.64 mg/g dry weight (DW) and in the in situ system, the range in concentration was between 8.06 and 36.31 mg/g DW. The highest amount of WA found in leaves was 7.37 and 41.42 mg/g DW in the in vitro and the in situ systems respectively. In roots, the highest WA concentration was 0.27 mg/g DW in the in vitro and 0.60 mg/g DW in the in situ system. There are distinct advantages in using the in vitro grown plants rather than those grown in the in situ system including the simplicity of design, efficient use of space and nutrition and a system which is soil and contaminant free. The proposed in vitro system is therefore ideal for utilization in molecular, enzymatic and biochemical studies

Draft genome sequence of Aspergillus flavus isolate TERIBR1, a highly tolerant fungus to chromium stress

Objectives: Aspergillus flavus isolate TERIBR1 was isolated from tannery sludge highly contaminated with chromium. During characterization process, it exhibited capability to adapt and grow in fungal growth media amended with chromium concentration as high as 250 mg/l. In order to understand the genetic underpinnings of the chromium tolerance trait, whole genome sequencing of the TERIBR1 genome was carried out. Information from the current genome will facilitate an understanding of the mechanisms underlying fungal adaptation to heavy metal stress and also heavy metal bioremediation. Data description: Here, we report the draft genome sequence along with the assembly and annotation methods used for genome sequence of the A. flavus isolate TERIBR1. The draft genome assembly size is estimated at 37.7 Mb coding for 13,587 genes and has high similarity to the reference genome of A. flavus strain NRRL3357

Phylogenetic analyses reveal molecular signatures associated with functional divergence among Subtilisin like Serine Proteases are linked to lifestyle transitions in Hypocreales

Background: Subtilisin-like serine proteases or Subtilases in fungi are important for penetration and colonization of host. In Hypocreales, these proteins share several properties with other fungal, bacterial, plant and mammalian homologs. However, adoption of specific roles in entomopathogenesis may be governed by attainment of unique biochemical and structural features during the evolutionary course. Due to such functional shifts Subtilases coded by different family members of Hypocreales acquire distinct features according to respective hosts and lifestyle. We conducted phylogenetic and DIVERGE analyses and identified important protein residues that putatively assign functional specificity to Subtilases in fungal families/species under the order Hypocreales. Results: A total of 161 Subtilases coded by 10 species from five different families under the fungal order Hypocreales was included in the analysis. Based on the presence of conserved domains, the Subtilase genes were divided into three subfamilies, Subtilisin (S08.005), Proteinase K (S08.054) and Serine-carboxyl peptidases (S53.001). These subfamilies were investigated for phylogenetic associations, protein residues under positive selection and functional divergence among paralogous clades. The observations were co-related with the life-styles of the fungal families/species. Phylogenetic and Divergence analyses of Subtilisin (S08.005) and Proteinase K (S08.054) families of proteins revealed that the paralogous clades were clear-cut representation of familial origin of the protein sequences. We observed divergence between the paralogous clades of plant-pathogenic fungi (Nectriaceae), insect-pathogenic fungi (Cordycipitaceae/Clavicipitaceae) and nematophagous fungi (Ophiocordycipitaceae). In addition, Subtilase genes from the nematode-parasitic fungus Purpureocillium lilacinum made a unique cluster which putatively indicated that the fungus might have developed distinctive mechanisms for nematode-pathogenesis. Our evolutionary genetics analysis revealed evidence of positive selection on the Subtilisin (S08.005) and Proteinase K (S08.054) protein sequences of the entomopathogenic and nematophagous species belonging to Cordycipitaceae, Clavicipitaceae and Ophiocordycipitaceae families of Hypocreales. Conclusions: Our study provided new insights into the evolution of Subtilisin like serine proteases in Hypocreales, a fungal order largely consisting of biological control species. Subtilisin (S08.005) and Proteinase K (S08.054) proteins seemed to play important roles during life style modifications among different families and species of Hypocreales. Protein residues found significant in functional divergence analysis in the present study may provide support for protein engineering in future

Polymer - Metal Nanocomplexes Based Delivery System: A Boon for Agriculture Revolution.

Metal nanoparticles are well known for their antimicrobial properties. The use of metalbased nanoparticles in the agricultural field has considerably increased globally by both direct and indirect means for the management of plant diseases. In this context, the development of controlled delivery systems for slow and sustained release of metal nanoparticles is crucial for prolonged antimicrobial activity. Polymers have emerged as a valuable carrier for controlled delivery of metal nanoparticles as agrochemicals because of their distinctive properties. The most significant benefits of encapsulating metal nanoparticles in a polymer matrix include the ability to function as a protector of metal nanoparticles and their controlled release with prolonged efficacy. This review focuses on loading strategies and releasing behavior of metal nanoparticles in the polymer matrix as antimicrobial agents for plant diseases. The Polymer-metal nanocomplexes (PMNs) comprise a biocompatible polymeric matrix and metal nanoparticles as active components of an antimicrobial agent, pesticides and plant growth regulators used to enhance the crop productivity