Identification and characterization of jasmonic acid- and linolenic acid-mediated transcriptional regulation of secondary laticifer differentiation in Hevea brasiliensis.

Hevea brasiliensis remains the primary crop commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. Here, we described the transcriptional events related to jasmonic acid (JA)- and linolenic acid (LA)-induced secondary laticifer differentiation (SLD) in H. brasiliensis clone RRIM 600 based on RNA-seq approach. Histochemical approach proved that JA- and LA-treated samples resulted in SLD in H. brasiliensis when compared to ethephon and untreated control. RNA-seq data resulted in 86,614 unigenes, of which 2,664 genes were differentially expressed in JA and LA-induced secondary laticifer harvested from H. brasiliensis bark samples. Among these, 450 genes were unique to JA and LA as they were not differentially expressed in ethephon-treated samples compared with the untreated samples. Most transcription factors from the JA- and LA-specific dataset were classified under MYB, APETALA2/ethylene response factor (AP2/ERF), and basic-helix-loop-helix (bHLH) gene families that were involved in tissue developmental pathways, and we proposed that Bel5-GA2 oxidase 1-KNOTTED-like homeobox complex are likely involved in JA- and LA-induced SLD in H. brasiliensis. We also discovered alternative spliced transcripts, putative novel transcripts, and cis-natural antisense transcript pairs related to SLD event. This study has advanced understanding on the transcriptional regulatory network of SLD in H. brasiliensis.

Phytochemical and Biological Characteristics of Mexican Chia Seed Oil.

The purpose of this research was to investigate the chemical profile, nutritional quality, antioxidant and hypolipidemic effects of Mexican chia seed oil (CSO) in vitro. Chemical characterization of CSO indicated the content of α-linolenic acid (63.64% of total fatty acids) to be the highest, followed by linoleic acid (19.84%), and saturated fatty acid (less than 11%). Trilinolenin content (53.44% of total triacylglycerols (TAGs)) was found to be the highest among seven TAGs in CSO. The antioxidant capacity of CSO, evaluated with ABTS•+ and DPPH• methods, showed mild antioxidant capacity when compared with Tocopherol and Catechin. In addition, CSO was found to lower triglyceride (TG) and low-density lipoprotein-cholesterol (LDL-C) levels by 25.8% and 72.9%respectively in a HepG2 lipid accumulation model. As CSO exhibits these chemical and biological characteristics, it is a potential resource of essential fatty acids for human use.

A thin-layer chromatography autographic method for the detection of inhibitors of the Salmonella PhoP-PhoQ regulatory system.

INTRODUCTION: The PhoP-PhoQ system from Salmonella enterica serovar Typhimurium controls the expression of factors that are critical for the bacterial entry into host cells and the bacterial intramacrophage survival. Therefore it constitutes an interesting target to search for compounds that would control Salmonella virulence. Localisation of such compounds in complex matrixes could be facilitated by thin-layer chromatography (TLC) bioautography. OBJECTIVE: To develop a TLC bioautography to detect inhibitors of the PhoP-PhoQ regulatory system in complex matrixes. METHODS: The TLC plates were covered by a staining solution containing agar, Luria-Bertani medium, 5-bromo-4-chloro-3-indolyl-ß-D-galactopyranoside (X-gal), kanamycin and a S. typhimurium strain that harbours a reporter transcriptional lacZ-fusion to an archetypal PhoP-activated gene virK. After solidification, the plate was incubated at 37°C for 16 h. RESULTS: A bioautographic assay suitable for the localisation of inhibitors of the PhoP-PhoQ system activity in S. enterica serovar Typhimurium present in a complex matrix is described. The assay was used to analyse a series of hydrolysed extracts prepared by alkaline treatment of crude plant extracts. Bioassay-guided analysis of the fractions by NMR spectroscopy and MS led to the identification of linolenic and linoleic acids as inhibitory input signals of the PhoP-PhoQ system. CONCLUSION: A practical tool is introduced that facilitates detection of inhibitors of the Salmonella PhoP-PhoQ regulatory system. The assay convenience is illustrated with the identification of the first naturally occurring organic compounds that down-regulate a PhoP-PhoQ regulatory system from a hydrolysed extract.

Comparative study of antioxidant and anti-inflammatory activities and genotoxicity of alcoholic and aqueous extracts of four Fabiana species that grow in mountainous area of Argentina.

ETHNOPHARMACOLOGICAL RELEVANCE: Fabiana species (Solanaceae family) extracts have long been used in Argentinean traditional medicine as anti-inflammatories, antiseptic, bone fractures and others diseases, but there is no scientific evidence which supports their use. AIM OF THE STUDY: The present study was conducted to evaluate the ability of aqueous and ethanolic extracts of four Fabiana species (Fabiana bryoides Phil., Fabiana punensis A.C. Arroyo, Fabiana densa J. Rèmy and Fabiana patagonica Speg.) to inhibit key enzymes in inflammatory processes, free radical scavenging properties and genotoxic effects. MATERIALS AND METHODS: HPLC-DAD of aqueous and ethanolic extracts from four Fabiana species was established. All Fabiana extracts were evaluated on their ability to inhibit hyaluronidase and lipoxygenase enzymes to assess their activity against inflammatory mediators. Antioxidant capacity was determined using the 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assays and ß-carotene-linolenic acid assay. Genotoxicity was evaluated by the Ames assay. RESULTS: The results indicated that the chromatographic patterns of four Fabiana species were different in quantity and absorption intensity of peaks. The alcoholic extract of Fabiana punensis was the most active scavenger of DPPH and ABTS(+) radicals (SC(50) values of 3.85 ± 0.24 and 2.56 ± 0.10 µgGAE/mL, respectively). Fabiana patagonica extracts exhibited the highest peroxyl radical scavenging activity compared with the other three taxa (IC(50) values between 1.00 ± 0.04 and 4.46 ± 0.40 µg GAE/mL for all extracts) and anti-lipoxygenase activity with IC(50) values between 12.5 and 15.5 µg GAE/mL. The absence of mutagenicity indicates that the DNA does not seem to be a relevant target for these extracts. Fabiana bryoides ethanolic extract showed an interesting effect: it inhibited spontaneous mutagenesis, which could be considered as an antimutagenic effect in the TA98 (+S9) and TA100 (+S9/-S9) strains. The potency differences found between the species could be consequence of the different phytochemical pattern observed by HPLC. CONCLUSIONS: The inhibitory effects on lipoxygenase and hyaluronidase, free radical scavenging activities and lack of genotoxicity of Fabiana extracts may support the folk use of Fabiana punensis, Fabiana patagonica, Fabiana bryoides and Fabiana densa as inhibitor of inflammatory mediators.

Characterisation of recombinant Hevea brasiliensis allene oxide synthase: effects of cycloxygenase inhibitors, lipoxygenase inhibitors and salicylates on enzyme activity.

Mechanical wounding and jasmonic acid (JA) treatment have been shown to be important factors in controlling laticifer differentiation in Hevea brasiliensis (rubber tree). With the long-term aim of potentially modifying the endogenous levels of JA in H. brasiliensis by gene transfer, we describe in this paper the molecular cloning of a H. brasiliensis allene oxide synthase (AOS) cDNA and biochemical characterisation of the recombinant AOS (His(6)-HbAOS) enzyme. The AOS cDNA encodes a protein with the expected motifs present in CYP74A sub-group of the cytochrome P450 super-family of enzymes that metabolise 13-hydroperoxylinolenic acid (13-HPOT), the intermediate involved in JA synthesis. The recombinant H. brasiliensis AOS enzyme was estimated to have a high binding affinity for 13-HPOT with a K(m) value of 4.02+/-0.64 microM. Consistent with previous studies, mammalian cycloxygenase (COX) and lipoxygenase (LOX) inhibitors were shown to significantly reduce His(6)-HbAOS enzyme activity. Although JA had no effect on His(6)-HbAOS, salicylic acid (SA) was shown to significantly inhibit the recombinant AOS enzyme activity in a dose dependent manner. Moreover, it was demonstrated that SA, and various analogues of SA, acted as competitive inhibitors of His(6)-HbAOS when 13-HPOT was used as substrate. We speculate that this effect of salicylates on AOS activity may be important in cross-talking between the SA and JA signalling pathways in plants during biotic/abiotic stress.