Drought response of Mucuna pruriens (L.) DC. inoculated with ACC deaminase and IAA producing rhizobacteria.

Drought is one of the major constraints limiting agricultural production worldwide and is expected to increase in the future. Limited water availability causes significant effects to plant growth and physiology. Plants have evolved different traits to mitigate the stress imposed by drought. The presence of plant growth-promoting rhizobacteria (PGPR) could play an important role in improving plant performances and productivity under drought. These beneficial microorganisms colonize the rhizosphere of plants and increase drought tolerance by lowering ethylene formation. In the present study, we demonstrate the potential to improve the growth of velvet bean under water deficit conditions of two different strains of PGPR with ACCd (1-Aminocyclopropane-1-Carboxylate deaminase) activity isolated from rainfed farming system. We compared uninoculated and inoculated plants with PGPR to assess: a) photosynthetic performance and biomass; b) ACC content and ethylene emission from leaves and roots; c) leaf isoprene emission. Our results provided evidence that under drought conditions inoculation with PGPR containing the ACCd enzyme could improve plant growth compared to untreated plants. Ethylene emission from roots and leaves of inoculated velvet bean plants was significantly lower than uninoculated plants. Moreover, isoprene emission increased with drought stress progression and was higher in inoculated plants compared to uninoculated counterparts. These findings clearly illustrate that selected PGPR strains isolated from rainfed areas could be highly effective in promoting plant growth under drought conditions by decreasing ACC and ethylene levels in plants.

Inducing mutations through γ-irradiation in seeds of Mucuna pruriens for developing high L-DOPA-yielding genotypes.

PURPOSE: To develop elite genotypes in Mucuna pruriens (L.) DC with high L-DOPA (L-3, 4 dihydroxyphenylalanine) yields, with non-itching characteristics and better adaptability by applying γ-irradiation. Molecular and chemical analysis was performed for screening based on specific characteristics desired for developing suitable genotypes. MATERIALS AND METHODS: Developed, mutant populations were analyzed for L-DOPA % in seeds through TLC (thin layer chromatography), and the results obtained were validated with the HPLC (High performance liquid chromatography). The DNA (Deoxyribonucleic acid) was isolated from the leaf at the initial stage and used for DNA polymorphism. RNA (Ribonucleic acid) was isolated from the leaf during maturity and used for expression analysis. RESULTS: The selected mutant T-I-7 showed 5.7% L-DOPA content compared to 3.18% of parent CIM-Ajar. The total polymorphism obtained was 57% with the molecular marker analysis. The gene expression analysis showed higher fold change expression of the dopadecarboxylase gene (DDC) in control compared to selected mutants (T-I-7, T-II-23, T-IV-9, T-VI-1). CONCLUSION: DNA polymorphism was used for the screening of mutants for efficient screening at an early stage. TLC was found suitable for the large-scale comparative chemical analysis of L-DOPA. The expression profile of DDC clearly demonstrated the higher yields of L-DOPA in selected mutants developed by γ-irradiation in the seeds of the control.

Lipid-lowering properties of protein-rich mucuna product

BACKGROUND: The objective of this study is to evaluate the effect of protein-rich mucuna product (PRMP) on lipid parameters of hyperlipidemic rats. METHODS: Hyperlipidemia was induced in male rats for 3 weeks through high-fat diet. After induction, 30 hyperlipidemic rats were divided into five groups of six rats: control group (CG) received casein and four groups received PRMP as protein source at different proportions: 8.2, 16.4, 24.6, and 32.8 % corresponding, respectively, to 25, 50, 75, and 100 %substitution of casein in the diet for 3 weeks. Lipid and oxidative stress parameters of rats were assessed. RESULTS: There were no significant differences in food intake and body weight loss among the experimental groups. The concentrations of the serum low-density lipoprotein cholesterol, total cholesterol, and triglycerides were lower in groups fed on PRMP 50, 75, and 100 % than in the CG group (p< 0.05). Histological analysis of the liver revealed that animals fed on PRMP diets presented a lower level of steatosis than the CG group. The most significant reduction of lipid parameters was obtained when PRMP was used as unique source of protein (PRMP 100 %). PRMP also influenced oxidative stress parameters as evidenced by a decrease in malondialdehyde and an increase in catalase and superoxide dismutase. CONCLUSIONS: These findings demonstrated that PRMP exerts hypolipidemic effect; it has a metabolic effect on endogenous cholesterol metabolism and a protector effect on the development of hepatic steatosis. Our results also suggest that PRMP could manage metabolic diseases associated with oxidative stress.

Central centrifugal cicatricial alopecia severity is associated with cowhage-induced itch.

BACKGROUND: Patients with central centrifugal cicatricial alopecia (CCCA) often suffer from varying degrees of itch, pain and burning sensations. However, the neural component of these skin sensations has not been assessed. OBJECTIVE: To conduct a comprehensive analysis of C nerve fibre function relating to itch and pain perception in patients with CCCA using thermosensory testing and experimental itch models. METHODS: Fifteen healthy African-American women and 16 African-American female patients with CCCA participated in the study and underwent quantitative computerized thermosensory testing to assess warmth and heat pain thresholds. Itch was induced using histamine iontophoresis and application of cowhage spicules, and the intensity of each itch was assessed. The association between itch intensity and CCCA severity score was examined. RESULTS: A positive correlation between CCCA severity score and peak itch ratings of cowhage on the lesional scalp (crown) was observed (P = 0·023, r = 0·562). Notably, the histamine peak itch rating was not found to have a significant correlation with CCCA severity score (P = 0·913). The crown also had significantly higher warmth and pain thresholds than the occiput in both healthy subjects and patients with CCCA. CONCLUSIONS: Our results suggest a putative role for the protease-activated receptor (PAR)-2, which is activated by cowhage, in the pathogenesis of CCCA. Future studies should examine PAR-2-directed therapeutics for patients with CCCA. Examining for itch and other dysaesthesias in patients with CCCA is of vital importance to dermatologists in assessing disease severity.

Separate peripheral pathways for pruritus in man.

Recent findings suggest that itch produced by intradermal insertion of cowhage spicules in human is histamine independent. Neuronal mechanisms underlying nonhistaminergic itch are poorly understood. To investigate which nerve fibers mediate cowhage induced itch in man, action potentials were recorded from cutaneous C-fibers of the peroneal nerve in healthy volunteers using microneurography. Mechano-responsive and -insensitive C-nociceptors were tested for their responsiveness to cowhage spicules, histamine, and capsaicin. Cowhage spicules induced itching and activated all tested mechano-responsive C-units (24/24), but no mechano-insensitive C-fibers (0/17). Histamine also induced itch, but in contrast to cowhage, it caused lasting activation only in mechano-insensitive units (8/12). In mechano-responsive C-units, histamine caused no or only short and weak responses unrelated to the time course of itching. Capsaicin injections activated four of six mechano-responsive fibers and three of four mechano-insensitive C-fibers. Cowhage and histamine activate distinctly different nonoverlapping populations of C-fibers while inducing similar sensations of itch. We hypothesize that cowhage activates a pathway for itch that originates peripherally from superficial mechano-responsive (polymodal) C-fibers and perhaps other afferent units. It is distinct from the pathway for histamine-mediated pruritus and does not involve the histamine-sensitive mechano-insensitive fibers.

Reduced allelopathic inhibition of lettuce (Lactuca sativa) growth caused by velvet bean (Mucuna pruriens) under 3D-clinorotation.

Allelopathy between Mucuna pruriens (velvet bean) and Lactuca sativa (lettuce) was studied under 3D-clinorotation. Growth of both roots and shoots of lettuce seedlings was suppressed by the presence of velvet bean. The degree of suppression was less on the clinostat compared to the normal static earth gravity. L-DOPA (L-3, 4-dihydroxyphenylalanine) is known to be a major substance in allelopathy of velvet bean. Amount of L-DOPA diffused out from a sintered filter paper into agar medium was compared between clinorotation and control group, and found no significant difference. It was concluded that some factors related to release, transport, and sensing phenomena of allelopathic substances may be responsible to the new findings in this study.

[Research plan to study allelopathy under microgravity].

Living organisms interact each others and form ecological system on the earth. Such interactions between organisms and species have been long known, and studied at a global scale. Allelopathy is a phenomenon observed in many plants that emit specific chemicals acting on other organisms, including animals and microorganisms, in either inhibitory or excitatory ways. We propose to study whether phenomena of allelopathy are modified under altered gravity or not. If biosynthesis, emission and sensing mechanism of allelopathic substances would be affected by gravity, many organisms and ecological system might show different behaviors based on the inter-organisms and species interactions under microgravity. In the macroscopic scale, transport of the substances between organisms is largely affected by convection induced by gravity. Furthermore, the fate of allelopathic substances in confined environment differs from that seen on the earth, because of lacking sink compartment for removal and producing exotic bio-active substances by man-made system. We design basic ground experiment to evaluate gravitational effects on allelopathy applying pseudo-microgravity. Our study contributes to the synthesis of ecological system and its control on spacecrafts and extraterrestrial bodies. It also makes possible to sustain qualitative human life even on the ground under confined artificial environment that dominates in many scenes.