Seed priming with co-flocs of Azospirillum and Pseudomonas for effective management of rice blast

A modified approach was adopted to develop co-flocs consisting of Azospirillum brasilense MTCC-125 and Pseudomonas fluorescens MTCC-4828. The results of our study revealed that both Azospirillum and Pseudomonas strains exhibited a higher survivability when embedded in the flocs. The survivability of the strains in co-floc was found to be higher when compared to the log phase vegetative cells in different inoculant carriers, spermosphere rhizoplane and rhizosphere. The co-floc treatment has also significantly increased the germination percentage and vigour index of rice. In the present study flocculation was found to play a major role in enhancing adhesion of both the strains to rice roots. The co-flocs were studied for their efficiency to induce resistance in rice crop against rice blast. The relative role of Azospirillum and Pseudomonas co-flocs in the induction of resistance against the phytopathogen was evaluated. It was found that when the activities of polyphenol oxidase, peroxidase and phenol were high and when the relative amounts of the sugars were low, the disease infestation was less and vice versa. The association of these compounds strongly implies their role as casual agents of induced resistance against Pyricularia oryzae.     

Lower Cerebrospinal Fluid/Plasma Fibroblast Growth Factor 21 (FGF21) Ratios and Placental FGF21 Production in Gestational Diabetes

Objectives

Circulating Fibroblast Growth Factor 21 (FGF21) levels are increased in insulin resistant states such as obesity, type 2 diabetes mellitus and gestational diabetes mellitus (GDM). In addition, GDM is associated with serious maternal and fetal complications. We sought to study human cerebrospinal fluid (CSF) and corresponding circulating FGF21 levels in women with gestational diabetes mellitus (GDM) and in age and BMI matched control subjects. We also assessed FGF21 secretion from GDM and control human placental explants.

Design

CSF and corresponding plasma FGF21 levels of 24 women were measured by ELISA [12 GDM (age: 26–47 years, BMI: 24.3–36.3 kg/m²) and 12 controls (age: 22–40 years, BMI: 30.1–37.0 kg/m²)]. FGF21 levels in conditioned media were secretion from GDM and control human placental explants were also measured by ELISA.

Results

Glucose, HOMA-IR and circulating NEFA levels were significantly higher in women with GDM compared to control subjects. Plasma FGF21 levels were significantly higher in women with GDM compared to control subjects [234.3 (150.2–352.7) vs. 115.5 (60.5–188.7) pg/ml; P<0.05]. However, there was no significant difference in CSF FGF21 levels in women with GDM compared to control subjects. Interestingly, CSF/Plasma FGF21 ratio was significantly lower in women with GDM compared to control subjects [0.4 (0.3–0.6) vs. 0.8 (0.5–1.6); P<0.05]. FGF21 secretion into conditioned media was significantly lower in human placental explants from women with GDM compared to control subjects (P<0.05).

Conclusions

The central actions of FGF21 in GDM subjects maybe pivotal in the pathogenesis of insulin resistance in GDM subjects. The significance of FGF21 produced by the placenta remains uncharted and maybe crucial in our understanding of the patho-physiology of GDM and its associated maternal and fetal complications. Future research should seek to elucidate these points.     

Bioactive Sulforaphane from in vitro Propagated Brassica Seedlings

Sulforaphane is a biologically active phytochemical found abundantly in Brassica species. Sulforaphane from eighteen samples of three‐day‐old in vitro seedlings from Brassicas, the Brassica oleracea and Brassica rapa varieties were analyzed by HPLC. San Martino, cavolfiore Alverda, cavolo verza riccio d'Asti and cavolfiore Minaret (4.57; 4.54; 4.53 and 4.53 [mg/g d.w], respectively) seedlings showed the highest level of sulforaphane. The presented data may be applicable to choose sulforaphane‐rich Brassica varieties for functional foods. A higher sulforaphane content in functional foods might offer health benefits or desirable physiological effects.     

Alkyladenine DNA glycosylase (Aag) in somatic hypermutation and class switch recombination

Somatic hypermutation (SHM) and class switch recombination (CSR) of immunoglobulin (Ig) genes require the cytosine deaminase AID, which deaminates cytosine to uracil in Ig gene DNA. Paradoxically, proteins involved normally in error-free base excision repair and mismatch repair, seem to be co-opted to facilitate SHM and CSR, by recruiting error-prone translesion polymerases to DNA sequences containing deoxy-uracils created by AID. Major evidence supports at least one mechanism whereby the uracil glycosylase Ung removes AID-generated uracils creating abasic sites which may be used either as uninformative templates for DNA synthesis, or processed to nicks and gaps that prime error-prone DNA synthesis. We investigated the possibility that deamination at adenines also initiates SHM. Adenosine deamination would generate hypoxanthine (Hx), a substrate for the alkyladenine DNA glycosylase (Aag). Aag would generate abasic sites which then are subject to error-prone repair as above for AID-deaminated cytosine processed by Ung. If the action of an adenosine deaminase followed by Aag were responsible for significant numbers of mutations at A, we would find a preponderance of A:T>G:C transition mutations during SHM in an Aag deleted background. However, this was not observed and we found that the frequencies of SHM and CSR were not significantly altered in Aag-/- mice. Paradoxically, we found that Aag is expressed in B lymphocytes undergoing SHM and CSR and that its activity is upregulated in activated B cells. Moreover, we did find a statistically significant, albeit low increase of T:A>C:G transition mutations in Aag-/- animals, suggesting that Aag may be involved in creating the SHM A>T bias seen in wild type mice.     

Single-amino-acid deletion in the RYR1 gene, associated with malignant hyperthermia susceptibility and unusual contraction phenotype

Malignant hyperthermia (MH) is an anesthetic-drug-induced, life-threatening hypermetabolic syndrome caused by abnormal calcium regulation in skeletal muscle. Often inherited as an autosomal dominant trait, MH has linkage to 30 different mutations in the RYR1 gene, which encodes a calcium-release-channel protein found in the sarcoplasmic reticulum membrane in skeletal muscle. All published RYR1 mutations exclusively represent single-nucleotide changes. The present report documents, in exon 44 of RYR1 in two unrelated, MH-susceptible families, a 3-bp deletion that results in deletion of a conserved glutamic acid at position 2347. This is the first deletion, in RYR1, found to be associated with MH susceptibility. MH susceptibility was confirmed among some family members by in vitro diagnostic pharmacological contracture testing of biopsied skeletal muscle. Although a single-amino-acid deletion appears to be a subtle change in the protein, the deletion of Glu2347 from RYR1 produces an unusually large electrically evoked contraction tension in MH-positive individuals, suggesting that this deletion produces an alteration in skeletal-muscle calcium regulation, even in the absence of pharmacological agents.     

Proline suppresses Rubisco activity by dissociating small subunits from holoenzyme

Proline caused irreversible inhibition (involving reduction in V(max) without altering K(m) for RuBP) in Rubisco activity. Proline-induced suppression in Rubisco activity did not exceed beyond approximately 65% of the original activity even upon exposure to higher levels of proline for prolonged duration. However, NaCl-induced reduction in Rubisco activity was reversible. Native PAGE analysis of Rubisco-incubated with proline showed the presence of two distinct bands corresponding to approximately 430 and approximately 28 kDa, but that incubated with NaCl showed a single band. SDS-PAGE analysis revealed that the approximately 430- and approximately 28-kDa bands represent octamers of large subunits and dimers of small subunits, respectively. These results demonstrated for the first time that proline suppresses Rubisco activity by bringing about dissociation of the small subunits from the octamer core of large subunits, probably by weakening hydrophobic interactions between them.