Plant growth-promoting traits of Streptomyces with biocontrol potential isolated from herbal vermicompost

Three strains of Streptomyces (CAI-21, CAI-26 and MMA-32) were earlier reported by us as having potential for biocontrol of charcoal rot of sorghum, caused by Macrophomina phaseolina (Tassi) Goid., and plant growth promotion (PGP) of the plant. In the present investigation, the three Streptomyces were characterised for their physiological traits (tolerance of salinity, temperature, pH and resistance to antibiotics) and further evaluated in the field for their PGP of rice, grown by a system of rice intensification methods. All three Streptomyces were able to grow in NaCl concentrations of up to 12% (except MMA-32), at pH values between 5 and 13 and temperatures between 20 and 40°C. They were highly resistant to ampicillin and trimethoprim (>800 ppm), sensitive to chloramphenicol, kanamycin and nalidixic acid (50–100 ppm) and highly sensitive to streptomycin and tetracycline (5–25 ppm). When evaluated for their PGP activity on seedlings of rice, % germination and shoot and root lengths were significantly enhanced over the control. In the field, the Streptomyces strains significantly enhanced the panicle length, filled grain numbers and weight, panicle weight, 1000 seed weight, tiller numbers, total dry matter, root length (39–65%), root volume (13–30%), root dry weight (16–24%), grain yield (9–11%) and stover yield (11–22%) over the control. In the rhizosphere soil (0–15 cm from root) at harvest, the population of actinomycetes was significantly enhanced as was microbial biomass carbon (27–83%) and nitrogen (24–43%), dehydrogenase activity (34–152%), available P (13–34%) and N (30–53%) and % organic carbon (26–28%). This study further confirms that the selected Streptomyces have PGP properties.     

Interaction of two fragments of cibacron blue F3GA having anthraquinone chromophores with basic polypeptides.

The interaction of two anthraquinone dyes, bromaminic acid 1-amino-4-bromo anthraquinone-2-sulphonic acid (BA) and 1-amino-4-(4'-aminophenylamino)-anthraquinone-2,3'-disulphonic acid (ASSO), with poly-L-lysine (PLL), poly-L-ornithine (PLO) and poly-L-arginine (PLA) has been studied. The flexibility of the side chain (chain length) and the geometry of the charge centre (tetrahedral/planar) of the polypeptide were found to affect the interaction. Further, both dyes induce ordered conformation (alpha or beta) for the three polypeptides, but the final conformation was found to depend on the polypeptide as well as the number of anionic sites on the ligand. While the bidentate ASSO-polypeptide complexes acquire beta-conformation, the monodentate BA distinguished between the three substrates and induces beta-conformation only for PLO.     

Regulation of aromatase induction by nuclear receptor coregulator PELP1

Estradiol (E2), estrogen receptor (ER), ER-coregulators have been implicated in the development and progression of breast cancer. In situ E2 synthesis is implicated in tumor cell proliferation through autocrine or paracrine mechanisms, especially in post-menopausal women. Several recent studies demonstrated activity of aromatase P450 (Cyp19), a key enzyme that plays critical role in E2 synthesis in breast tumors. The mechanism by which tumors enhance aromatase expression is not completely understood. Recent studies from our laboratory suggested that PELP1 (Proline, Glutamic acid, Leucine rich Protein 1), a novel ER-coregulator, functions as a potential proto-oncogene and promotes tumor growth in nude mice models without exogenous E2 supplementation. In this study, we found that PELP1 deregulation contributes to increased expression of aromatase, local E2 synthesis and PELP1 cooperates with growth factor signaling components in the activation of aromatase. PELP1 deregulation uniquely up-regulated aromatase expression via activation of aromatase promoter I.3/II. Analysis of PELP1 driven mammary tumors in xenograft as well as in transgenic mouse models revealed increased aromatase expression. PELP1-mediated induction of aromatase requires functional Src and PI3K pathways. Chromatin immuno precipitation (ChIP) assays revealed that PELP1 is recruited to the Aro 1.3/II aromatase promoter. HER2 signaling enhances PELP1 recruitment to the aromatase promoter and PELP1 plays a critical role in HER2-mediated induction of aromatase expression. Mechanistic studies revealed that PELP1 interactions with orphan receptor ERRα, and histone demethylases play a role in the activation of aromatase promoter. Accordingly, ChIP analysis showed alterations in histone modifications at the aromatase promoter in the model cells that exhibit local E2 synthesis. Immunohistochemical analysis of breast tumor progression tissue arrays suggested that deregulation of aromatase expression occurs in advanced-stage and node-positive tumors, and that cooverexpression of PELP1 and aromatase occur in a sub set of tumors. Collectively, our results suggest that PELP1 regulation of aromatase represent a novel mechanism for in situ estrogen synthesis leading to tumor proliferation by autocrine loop and open a new avenue for ablating local aromatase activity in breast tumors.     

1-Benzyl-1,2,3,4-tetrahydroisoquinoline-6,7-diols as novel affinity and photoaffinity probes for beta-adrenoceptor subtypes

Trimetoquinol (TMQ, 1) is a potent non-selective beta-adrenoceptor (beta-AR) agonist possessing a tetrahydroisoquinoline (THI) structure. The binding site for 1-trimethoxybenzyl group of 1, which distinguishes it from classical catecholamines, is unknown. Affinity and photoaffinity labeled compounds are good tools to determine the exact interaction between a ligand and a specific amino acid(s) in a receptor. In this study, we designed and synthesized a series of affinity 6, 12, 18, and photoaffinity 24, 29 labeled analogues of TMQ. All of these compounds were full agonists and demonstrated an equal or greater binding affinity and functional activity as compared to TMQ on beta1-, beta2-, and beta3-AR. Washout experiments on Chinese hamster ovary (CHO) cells expressing hu beta2-AR were helpful in identifying the isothiocyanate 18 and the azide 24 as very effective affinity and photoaffinity labels at this receptor subtype.     

Molecular evidence for species-level distinctions in clouded leopards

Among the 37 living species of Felidae, the clouded leopard (Neofelis nebulosa) is generally classified as a monotypic genus basal to the Panthera lineage of great cats. This secretive, mid-sized (16-23 kg) carnivore, now severely endangered, is traditionally subdivided into four southeast Asian subspecies (Figure 1A). We used molecular genetic methods to re-evaluate subspecies partitions and to quantify patterns of population genetic variation among 109 clouded leopards of known geographic origin (Figure 1A, Tables S1 ans S2 in the Supplemental Data available online). We found strong phylogeographic monophyly and large genetic distances between N. n. nebulosa (mainland) and N. n. diardi (Borneo; n = 3 individuals) with mtDNA (771 bp), nuclear DNA (3100 bp), and 51 microsatellite loci. Thirty-six fixed mitochondrial and nuclear nucleotide differences and 20 microsatellite loci with nonoverlapping allele-size ranges distinguished N. n. nebulosa from N. n. diardi. Along with fixed subspecies-specific chromosomal differences, this degree of differentiation is equivalent to, or greater than, comparable measures among five recognized Panthera species (lion, tiger, leopard, jaguar, and snow leopard). These distinctions increase the urgency of clouded leopard conservation efforts, and if affirmed by morphological analysis and wider sampling of N. n. diardi in Borneo and Sumatra, would support reclassification of N. n. diardi as a new species (Neofelis diardi).