Production of antimicrobial metabolites known as phytoalexins is considered as one of the initial and main barriers to inhibit pathogen development in local infected aerial tissues. Capsidiol is the main bicyclic sesquiterpene phytoalexin in tobacco (Nicotiana tabacum) and chili pepper (Capsicum annuum). Production of 5-epi-aristolochene by the corresponding sesquiterpene cyclase enzymes is considered the critical step in capsidiol biosynthesis. To analyze the transcriptional activation of chili pepper 5-epi-aristolochene synthase gene expression in response to several pathogen-associated molecular patterns, a 1,455 bp promoter fragment upstream start codon was fully sequenced and fused to β-glucuronidase reporter gene. Analyses of spatial and temporal patterns of hybrid gene expression were carried out in transgenic tobacco plants. Surprisingly β-glucuronidase was detected in both, the locally treated and the phylotactically adjacent leaves. A particular systemic gene expression was localized in the immediate vascular tissue. The activation patterns of 5-epi-aristolochene synthase transcripts and detection of capsidiol in corresponding tobacco and pepper systemic leaves confirmed these results. This expression pattern might be mediated by reactive oxygen species. This is the first report of a highly localized systemic gene expression of enzymes directly involved in sesquiterpene phytoalexin biosynthesis in leaves, elicited by pathogen-associated molecular patterns.

is a traditional edible plant consumed and commercialized in the northern highlands of Puebla, México. The present study reports the seasonal variation in proximate analysis as well as organic acids, carotenoids and flavonoids content in both leaves and stalks of this plant. The stalks contained low concentrations of protein (~3%), fiber (~1.5%) and nitrogen free extract (~0.26%) during the time of study. Both organs showed contents of oxalic acid (91-103 mg 100 g FW), ascorbic acid (50-65 mg 100 g FW), lutein (1-2.5 mg 100 g FW), β-carotene (1-3 mg 100 g FW), quercetin (1.3-2.7 mg 100 g DW) and rutin (0.5-1.7 mg 100 g DW). Antioxidant activity against DPPH was observed by the stalk extracts from 30% methanol (IC, 0.21-0.37 mg L), pure methanol (IC, 0.14-0.21 mg L) and hexane: acetone (IC, 0.77-1.21 mg L). In vitro anti-HMG-CoA reductase (IC, 0.07-0.36 mg L) and anti-alpha-glucosidase (IC, 0.28-0.43 mg L) activities were observed in extracts from the edible stalks from pure methanol and 30% methanol. The leaf extracts from 30% methanol inhibited the growth of pv. tabaci TBR2004 (MIC, 254 µg mL), pv. tomato DC3000 (MIC, 423 µg mL), pv. glycinea (MIC, 605 µg mL) and AB299158 (MIC, 162 µg mL). contained valuable phytochemicals associated to nutraceutical and biological properties. However, the consumption of the fresh stalks must be carefully considered because of the high oxalate content.

We report the results of in vitro anti-lipase and antioxidant assays using crude ethanolic extracts from 30 plants grown in Oaxaca, México. Anti-lipase tests were performed by using porcine pancreatic lipase (PPL) [EC 3.1.1.3] from Affymetrix/USB. The extracts of Solanum erianthum, Salvia microphylla, Brungmansia suaveolens and Cuphea aequipetala showed up to 60% PPL inhibition. The effect of these extracts on the kinetic parameters of PPL (Km= 0.36 mM, and Vmax=0.085 mM min -1) revealed that the alcoholic preparations of S. erianthum and C. aequipetala engendered a non-competitive inhibition (Vmax=0.055 mM min -1; Vmax= 0.053 mM min -1), whereas those of S. microphylla and B. suaveolens produced a mixed inhibition (Km= 0.567 mM, Vmax=0.051 mM min _1; Km=0.643 mM, Vmax= 0.042 mM min ¹). In addition to these findings, seven extracts from different plants were able to inhibit PPL in the range of 30-50%. Antioxidant tests against 2,2-Diphenyl-1-picryl hydrazyl (DPPH) confirmed that Arctostaphylos pungens, Gnaphalium roseum, Crotalaria pumila, Cuphea aequipetala, Rhus chondroloma, and Satureja laevigata possess relevant antioxidant activity (IC(5)0=50-80 μg mL¹). The general composition of the most effective ethanolic extracts was obtained in order to confirm their known chemistry reported by previous works. Comprehensive chemical analysis of the ethanolic extracts and their poisoning effects suggests that S. microphylla, C. aequipetala and A. pungens could be considered as the best sources with both desired properties.

Introduction Nicotiana tabacum is a plant model intensively used in the bio‐engineering pharmaceutical industry as a platform to produce drugs and therapeutic agents. Currently, no information regarding the non‐targeted metabolome of transgenic tobacco containing recombinant regulatory sequences is available. Objective To compare the proton nuclear magnetic resonance (1H‐NMR) metabolomics profiling of a recombinant Nicotiana tabacum strain containing a promoter of a sesquiterpene cyclase from Capsicum annuum driving GUS expression, versus wild‐type samples. Methodology The non‐targeted 1H‐NMR metabolome was obtained and processed by principal component analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS‐DA). The differential metabolites were quantified by quantitative NMR. Results PCA and OPLS‐DA revealed 37 metabolites including 16 discriminant compounds for transgenic samples. Ethanol (0.4 mg g‐1), the main differential compound, was exclusively detected in transgenic tobacco; however, high levels of formate (0.28 mg g‐1) and acetate (0.3 mg g‐1) were simultaneously observed in the same group of samples. Cembratriene‐4,6‐diol, an antitumour and neuroprotective compound, and capsidiol, a known phytoalexin, increased by about 30% in transgenic samples. In addition, the endogenous levels of the antioxidant caffeoylquinic acid isomers increased by 50% in comparison to those of wild‐type tobaccos. Conclusion Our results support the occurrence of metabolic differences between wild type and transgenic tobacco containing a promoter of a Capsicum sesquiterpene cyclase gene. Interestingly, the recombinant transgenic strain studied accumulated high amounts of added value compounds with biological activity.

No abstract