Oleosomes in some nitrogen-fixing root nodules

The high energy-demanding process of nitrogen fixation in symbiotic root nodules is generally supported by a supply of carbon compounds derived from current photosynthate of the host plant. However, in Arachis hypogaea L (peanut) nodules, which have oleosomes (lipid bodies) in the infected cells, the lipid catabolism may supplement the energy supply in case of photosynthate stress. The present investigation was undertaken to further study oleosomic metabolism in Arachis hypogaea and four other legumes: A. pintoi L., A. duranensis L., A. batizocoi L. and Lathyrus maritimus L. (Bigel) (beach pea) nodules where oleosomes are present. -- The oleosomes of A. hypogaea root nodules contained diacylglycerol (DAG), triacylglycerol (TAG), phospholipids (PL) and oleosins. The oleosomes varied in size, electron density and in the width of a less electron-dense peripheral layer. Four oleosin bands having molecular weights 66.0 KD, 61.1 KD, 56.3 KD and 10.0 KD could be resolved by polyacrylamide gel electrophoresis. -- The development of symbiosis and oleosome distribution was studied in three wild species of Arachis i.e. A. pintoi, A. duranensis and A. batizocoi. Oleosomes were present in the infected cells of A. pintoi during the infection process and before establishment of symbiosis. In A. duranensis and A. batizocoi oleosomes persisted during symbiosis in mature nodules. A.pintoi mature nodules were devoid of oleosomes in infected cells, but reappeared during senescence. Another interesting feature in this species was the reversion of spherical bacteroids into rod-forms within the confines of the senescent nodule tissue. -- Studies on the distributional pattern of oleosomes in the root nodules of naturally growing L. maritimus (beach pea) revealed that the pre-winter nodules were filled with large numbers of oleosomes and amyloplasts in uninfected interstitial and parenchyma cells. These storage organelles could not be seen in the cells of nodule sampled during post- winter periods before aerial shoots emerged. The results indicate that either the oleosomes are catabolized slowly during the winter months, to allow the nodules to survive the extreme cold temperatures or they are rapidly mobilized just before the growing season. The olesomes in beach pea nodules seem to serve as storage organelles in the uninfected and parenchyma cells and not directly related to nitrogen fixation per se. The overwintered nodules are capable of resuming nitrogen fixation due to the presence of persistent infection threads with rhiozobia and many rod-shaped Rhizobium among the senescent infected cells

Indole: A novel signaling molecule and its applications

297-310  A variety of intercellular signal molecules, such as, the most studied N-acyl-homoserinelactones (AHLs) in Gram-negative bacteria, autoinducer (AI-2) in both Gram-negative and Gram-positive bacteria, and signal peptides in Gram-positive bacteria, have been discovered over the last 20 years. Although it has been known for over 100 years that many bacteria produce indole, the real biological roles of this molecule are only now beginning to be explored. Recently, indole has been identified as signaling molecule in diverse functions and those attributed to indole include extracellular signal, drug resistance, plasmid stability, virulence control and biofilm formation<i style="mso-bidi-font-style: normal">. Indole is widespread in the natural environment and a variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole. To date, approx 85 bacterial species are known to produce indole. Both natural and synthetic indole derivatives are being used as antimicrobial agents.   Understanding indole signaling will help to develop effective antimicrobial or antivirulence strategies and their biotechnological applications. Indole works at both high and low cell density. Though it does not behave as quorum sensing molecule, but some mode of its action is like quorum sensing molecule. Current postgenomic studies already indicate a role for IAA (indole acetic acid) signaling in bacteria and microorganism-plant interactions. Indole signaling appears to be important in microbial consortia and may influence the digestive and immune systems in humans. Recently, synthetic indole <span style="background:white; mso-bidi-font-weight:bold">7-fluoroindole (7FI) has been reported as a potential candidate for use in an antivirulence approach against persistent Pseudomonas aeruginosa infection. The present review aims to address the role of indole as novel signaling molecule in diverse bacterial genes. </span

Synergism study of Bacopa monnieri and Piriformospora indica and its impact on Biomass and metabolite

Abstract Background A symbiotic connection between Piriformospora indica and Bacopa monnieri (L.) Wettest, obtained through co-cultivation synergism, was found to improve growth, biomass production, and bacoside content in the plants. Brahmi (B. monnieri L.), a well-known Indian plant prized for its memory-boosting properties, has a lengthy history and a premium price tag. Because of its remarkable ability to colonize a wide variety of plant species, the axenically cultivable mycorrhiza-like endophytic fungus P. indica has gained a lot of interest recently. Methods In the current study, fungal spores from recently revived cultures were added to jam bottles next to rooted Brahmi plants for in vitro co-cultivation. The control plants were left without fungal discs. Pre-rooted micro-propagated Brahmi plants were treated with agar discs containing actively growing hyphae. For a period of 3 months, both trials were conducted with a fully randomized setup. Microscopy of the treated and control plant roots verified co-cultivation. Results Microscopic examination of the roots of co-cultivated plants reveals a high degree of colonization with host plants. These endophytic fungal structures include intracellular chlamydospores, and arbuscules, an intercellular and intracellular hyphae network, and a mycelial network on the root surface. In both in vitro and in vivo co-cultivation studies, the plant extended the host plant’s lifespan in 3 months by displaying continuous regeneration; in contrast, the control plant displayed signs of senescence. With biomass exceeding the control by 1.18 times in vivo and 1.28 times in vitro. In vitro, co-cultivation circumstances also led to an increase in the rate of utilization of nutritional medium. In comparison to the control, the amount of bacoside increases to 100% in vivo after a month of co-cultivation and 33% in vitro after 3 months. Conclusions In the present investigation, in vivo co-cultivation showed a favorable interaction effect on biomass production as well as bacoside content, which can satisfy the raw material demands of Brahmi plants in pharmaceutical industries

Novel Di-Tertiary-Butyl Phenylhydrazones as Dual Cyclooxygenase-2/5- Lipoxygenase Inhibitors: Synthesis, COX/LOX Inhibition, Molecular Modeling, and Insights into Their Cytotoxicities

Although dual inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipoxygenase (5-LOX) enzymes is highly effective than targeting COX or LOX alone, there are only a few reports of examining such compounds in case of colorectal cancers (CRC). In the present work we report that the novel di-tert-butyl phenol-based dual inhibitors DTPSAL, DTPBHZ, DTPINH, and DTPNHZ exhibit significant cytotoxicity against human CRC cell lines. Molecular docking studies revealed a good fit of these compounds in the COX-2 and 5-LOX protein cavities. The inhibitors show significant inhibition of COX-2 and 5-LOX activities and are effective against a panel of human colon cancer cell lines including HCA-7, HT-29, SW480 and intestinal Apc10.1 cells as well as the hyaluronan synthase-2 (Has2) enzyme over-expressing colon cancer cells, through inhibition of the Hyaluronan/CD44v6 cell survival pathway. Western blot analysis and qRT-PCR analyses indicated that the di-tert-butyl phenol-based dual inhibitors reduce the expression of COX-2, 5-LOX, and CD44v6 in human colon cancer HCA-7 cells, while the combination of CD44v6shRNA and DTPSAL has an additional inhibitory effect on CD44v6 mRNA expression. The synergistic inhibitory effect of Celecoxib and Licofelone on CD44v6 mRNA expression suggests that the present dual inhibitors down-regulate cyclooxygenase and lipoxygenase enzymes through CD44v6. The compounds also exhibited enhanced antiproliferative potency compared to standard dual COX/LOX inhibitor, viz. Licofelone. Importantly, the HA/CD44v6 antagonist CD44v6shRNA in combination with synthetic compounds had a sensitizing effect on the cancer cells which enhanced their antiproliferative potency, a finding which is crucial for the anti-proliferative potency of the novel synthetic di-tert-butyl phenol based dual COX-LOX inhibitors in colon cancer cells