Evaluation of DNA markers for molecular identification of three Piper species from Brazilian Atlantic Rainforest.

Piper is one of two large genera in the Piperaceae, and with ca. 2600 species, is one of the largest plant genera in the world. Species delimitation and evaluation of genetic diversity among populations are important requisites for conservation and adequate exploitation of economically important species. DNA barcoding has been used as a powerful tool and a practical method for species characterization and delimitation. The present work aims to evaluate molecular markers for barcoding three Piper species native to Brazil: P. gaudichaudianum ("jaborandi" or "pariparoba"), P. malacophyllum ("pariparoba-murta") and P. regnellii ("caapeba" or "pariparoba"). A reference DNA barcode library was developed using sequences of three candidate regions: ITS2, trnH-psbA and rbcL. Transferability of the microsatellite (SSR) primers Psol 3, Psol 6 and Psol 10, designed originally for Piper solmsianum, to the three Piper species was also evaluated. The discriminatory power of the markers was based on the determination of inter- and intraspecific distances, phylogenetic reconstruction, and clustering analysis, as well as BLASTn comparison. Sequences of ITS2 enabled efficient species identification by means of the BLASTn procedure. Based on these sequences, intraspecific divergence was lower than interspecific variation. Maximum Parsimony analyses based on ITS2 sequences provided three resolved clades, each corresponding to one of the three analysed species. Sequences of trnH-psbA and rbcL had lower discriminatory value. Analyses combining sequences of these regions were less effective toward the attainment of resolved and strongly supported clades of all species. In summary, robustly supported clades of P. regnellii were obtained in most of the analyses, based either on isolated or combined sequences. The SSRs primers Psol 3, Psol 6 and Psol 10 were shown to be transferable to P. gaudichaudianum and P. regnellii, but not to P. malacophyllum. Preliminary cluster analyses based on the polymorphism of the amplified products suggested that Psol 3 has lower potential than Psol 6 and Psol 10 for discrimination of Piper species.

Origin and evolution of the genus Piper in Peninsular India.

The evolution of Peninsular Indian biodiversity has been a fascinating topic of research due to historical connections of this region to the ancient Gondwanaland. We investigated the phylogeny and historical biogeography of nearly all extant species of the genus Piper reported from the region to assess the biogeographical origins and test mechanisms of lineage diversification (dispersal, vicariance and in situ radiation) of this highly diverse genus of angiosperms commonly found in the understory of evergreen forests. The phylogeny of 21 species of Piper reported from Peninsular India was reconstructed for the first time, which included three new putative species from the Western Ghats. We used BEAST for the divergence time estimations (using three constraints), and ancestral range estimations were performed with the dated phylogenetic tree using BIOGEOBEARS. Divergence dating analysis revealed that the genus Piper originated during lower Cretaceous around 110 Ma [95% highest posterior density (HPD): 116-105 Ma] and colonized Peninsular India five times independently, from Southeast Asia starting from the Oligocene. The two major dispersals into India occurred during the periods of 27.3 Ma (95% HPD: 35.8-19.9.) and 15.5 Ma (95% HPD: 24.9-7.11). This was followed by rapid radiations in some lineages with subsequent back dispersals to Southeast Asia. Our study indicates that dispersals from Southeast Asia led to the arrival of Piper to Indian subcontinent following the Indo-Eurasian collision. Members of Piper have colonized and diversified within the climatically stable habitats of Peninsular India. Furthermore, the present study provides evidence for the Miocene overland dispersal of Piper species to Africa from South Asia.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications.

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

Ethnomedical uses and pharmacological activities of most prevalent species of genus Piper in Panama: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Piperaceae is the fifth largest family of plants in Panama. This review focuses on the ethnomedical uses of the most prevalent Panamanian species and biological activities of their extracts and/or constituents both in Panama and worldwide. Many species have a plethora of ethnomedical uses such as antibacterial, antifungal, anti-inflammatory, anticancer, antidiabetic, anti-Helicobacter pylori, antiulcer, antiprotozoal, estrogenic, insecticidal, local anesthetic, diuretic, and for women's health conditions. AIM OF THE REVIEW: The aim of this review is to compile all ethnomedical uses of most prevalent species of Piper in Panama, and their extracts or phytoconstituents worldwide, through a complete literature search, so that it may allow selection of potential unexplored Piper species for future research and development of phytotherapeuticals for important ailments. METHODOLOGY: This review conducted a thorough search in books and databases such as Google Scholar, PubMed, Sci-Finder, Scopus, ACS publications, Science Direct, and Reaxys (Elsevier), until October of 2017. The information provided in this review is based on peer-reviewed papers only in English. The key words used to search were: "Piper", "Piperaceae", "Panama", "Pharmacological activity", "Chemistry," "Toxicity," and "Clinical studies". Scientific names of the plants were validated through www.tropicos.org. Potential full-texts of eligible papers, irrespective of database, were identified. Study selection and data extraction were conducted by one author (AIS) and confirmed by others (MPG, ADA). The extracted data were summarized in tabular form and a narrative description was used to provide a summary of updated information. RESULTS: The ethnomedical uses of most prevalent 23 Panamanian species of Piper both in Panama as well in the world are provided. Of these species only Piper arboreum, Piper auritum, Piper cordulatum, Piper hispidum, Piper dariense, Piper multiplinervium and Piper umbellatum have ethnomedical uses in Panama. Some of the uses are by native Amerindians of Panama. These include ailments such as liver pains, common colds, skin infections, insecticidal, as a bath to alleviate colds, snakebites, different types of pains, skin ailments, wound healing, rheumatism, women's health, antipyretic, and anti-inflammatory. Other Panamanian species are widely used in many countries of the world. Of all the Piper species, P. aduncum has the most ethnomedical uses. Panamanian uses are different from the ones in other countries. A total of 61 compounds present in Piper species reported in this review have shown a variety of biological activities in vitro. These compounds belong to different chemical types, such as chromenes, amides, alkaloids, benzopyrans, benzoates, essential oils, pyrrolidines, flavokaines, chalcones, methylenedioxy propiophenones, cinnamates, monoterpenes, sesquiterpenes, phenols, among others. From this review it is evident that extracts and pure compounds isolated from Piper species have shown a wide array of mainly in vitro activity and some ethnomedical uses may be correlated with their activities reported. CONCLUSIONS: Plants of this genus have provided bioactive species, both from crude extracts and pure compounds thus substantiating their efficacy in traditional medicine. In vivo and toxicological studies are still limited, but the results of different activities of Piper reported point out the great potential of these species for obtaining bioactive principles that may be useful in treating diseases. However, a thorough investigation of Piper species relating to chemistry, in vivo pharmacological activities, with emphasis on their mechanism of action, safety and efficacy and toxicity is warranted.

Isolation of Monoterpene Dihydrochalcones from Piper montealegreanum Yuncker (Piperaceae).

Four new compounds were isolated from the branches of Piper montealegreanum Yuncker, a shrub found in the Amazon rainforest, including two new dihydrochalcones named claricine (1) and maisine (2), a cinnamic acid derivative 3 and a phenylalkanoid 4, along with a porphyrin identified as the known compound phaeophytin a (5). The structures were established using spectroscopic experiments, including 1D and 2D NMR and HRESIMS experiments, performed on the two monoterpene dihydrochalcones and their monoacetyl derivatives. The structural diversity of these substances is very important for the Piper genus chemotaxonomy.

PRE-CLINICAL EVALUATION OF EXTRACTS AND ESSENTIAL OILS FROM BETEL-LIKE SCENT PIPER SPECIES IDENTIFIED POTENTIAL CANCER TREATMENT.

BACKGROUND: Nine Piper species with betel-like scents are sources of industrial and medicinal aromatic chemicals, but there is lack of information on cytotoxicity and genotoxicity for human safety, including how these plants impact human cervical cancer cell line. METHODS: Plant leaves were extracted with hexane and hydro-distilled for essential oils. The extracts and oils were pre-clinically studied based on cyto - and genotoxicity using microculture tetrazolium (MTT) and comet assays. RESULTS: The crude extracts showed an IC50 in leukocytes and HeLa cells of 58.59-97.31 mg/ml and 34.91-101.79 mg/ml, the LD50 is higher than 5000 mg/kg. With lower values than the crude extracts, the essential oils showed an IC50 in leukocytes and HeLa cells of 0.023-0.059 µg/ml and 0.025-0.043 µg/ml the LD50 is less than 50 mg/kg. IC50 values showed that the essential oils were highly toxic than the crude extracts. At the level of human genetic materials, the crude extracts of two species, including P. betloides and P. crocatum, showed a significant toxicity (p < 0.05) in leukocytes. The other samples were non-toxic. The crude extracts of all samples showed significant genotoxicity in HeLa cells. The essential oils of all studied Piper species showed insignificant toxicity in leukocytes. For HeLa cells, the eight-studied species showed significant toxicity in HeLa cells, whereas only P. submultinerve showed insignificant toxicity. CONCLUSION: The crude extracts and essential oils should be tested as putative cervical cancer treatments due to less toxicity in human normal cells.

Holopothrips chaconi sp.n. (Thysanoptera: Phlaeothripinae) from leaf-vein galls on Piper species (Piperaceae) in Costa Rica

AbstractMost species of the Neotropical genus Holopothrips are associated with plant galls but very little is known about their biology. Here, we provide observations on the biology of a new species of Holopothrips associated with leaf-vein galls on four species of Piper at a cloud forest site (Zurquí de Moravia) in Costa Rica. This species colonized the galls soon after the gall-inducing cecidomyiid or one of its parasitoids emerged, and several generations of thrips appeared to occupy the empty galls. A total of 175 empty galls from 34 leaves were collected, brought to the laboratory for dissection under the microscope, and the contents quantified. Holopothrips occupied approximately 75 % of the galled leaves and among the latter they occupied about 40 % of the galls. Every combination of adults, nymphs and eggs was found, which implies that adult thrips move in and out of galls, and possibly do not defend their galls from invasion by other members of their species. However, when disturbed, both nymphs and adults raise the tip of their abdomen and emit a distinctive odor, suggesting a defensive reaction against potential predators. Preliminary evidence suggests that they feed on gall tissue lining the inner cavity and spend very little time outside the galls. The thrips is described as a new species, and is one of only four known species of Holopothrips to have the unusual condition of two pairs of epimeral setae on the pronotum. This new species was compared to these other three Holothrips species, and the remarkable variation of the female spermatheca and the male sternal pore plate is illustrated. Further research is needed to confirm that several generations of thrips occupy empty galls, to determine whether adult thrips do indeed move between galls, and to explore in greater detail their possible chemical defense. Rev. Biol. Trop. 63 (4): 1035-1042. Epub 2015 December 01.

ResumenLa mayoría de las especies del género neotropical Holopothrips se asocian a las agallas de plantas pero se sabe muy poco de su biología. Aquí, se provee observaciones sobre la biología de una nueva especie de Holopothrips que se asocia a las agallas de venas foliares en cuatro especies de Piper en un bosque nuboso (Zurquí de Moravia) de Costa Rica. Esta especie coloniza las agallas luego de que el cecidómido inductor o un parasitoide del mismo emerge, y aparentemente varias generaciones de trips ocupan las agallas vacías. Un total de 175 agallas vacías en 34 hojas fueron recolectadas, llevadas al laboratorio para disección bajo el microscopio y se cuantificó su contenido. Holopothrips ocupaba aproximadamente el 75 % de las hojas con agallas y en ellas el 40 % de las agallas. Se encontró toda combinación de adultos, ninfas y huevos, lo cual implica que los trips adultos entran y salen y posiblemente no defienden sus agallas de la invasión de otros miembros de su especie. Sin embargo, adultos y ninfas, levantan la punta del abdomen al ser perturbados, emitiendo un olor distintivo que sugiere una reacción defensiva ante posibles depredadores. La evidencia preliminar indica que se alimentan del tejido interior de la agalla y pasan muy poco tiempo fuera de la misma. Se describe la especie nueva y es una de sólo cuatro especies conocidas de Holopothrips que poseen dos pares de setas epimorales en el pronoto. Al compararla con estas otras especies surge una marcada variación en la espermateca de la hembra y en las placas del poro esternal en el macho, los cuales se ilustran. Se requiere más investigación para confirmar la sugerencia que varias generaciones de trips ocupan las agallas vacias, para determinar si es cierto que los trips adultos se mueven entre agallas, y para explorar en más detalle la supuesta defensa química.

Volatile Constituents of Three Piper Species from Vietnam.

The chemical compositions of the essential oils obtained by hydrodistillation of three Piper plants grown in Vietnam are reported. The analysis was achieved by means of gas chromatography with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main constituents of the leaf oil of Piper majusculum Blume were ß-caryophyllene (20.7%), germacrene D (18.6%) and ß-elemene (11.3%). The quantitatively significant compounds of the volatile oils of P. harmandii C. DC were sabinene (leaves, 14.5%; stems, 16.2%), benzyl benzoate (leaves, 20.0%; stems, 29.40%) and benzyl salicylate (leaves, 14.1%; stems, 24.3%). Also, α-cadinol (17.0%) was identified in large proportion in the leaf oil. However, sabinene (leaves, 17.9%; stems, 13.5%), benzyl benzoate (leaves, 20.5%; stems, 32.5%) and ß-eudesmol (leaves, 13.8%; stems, 8.4%) were the main constituents of P. brevicaule C. DC. This is the first report on the volatile constituents of both P. harmandii and P. brevicaule.

Avaliação da atividade antimicobacteriana da lignana diidrocubebina extraída da Piper cubeba e de seus derivados semissintéticos / Evaluation of antimycobacterial activity of dihydrocubebin lignan extracted from Piper cubeba and its semisynthetic derivatives

RESUMO: A atividade antimicobacteriana de diidrocubebina (1), uma lignana dibenzilbutanodioica obtida a partir de extrato etanólico de sementes da Piper cubeba, e seus derivados foram avaliados in vitro contra três diferentes cepas de Mycobacterium utilizando o método de microdiluição. Dentre as lignanas avaliadas 3 e 4 foram as mais ativas, exibindo valores de CIM de 62,5 µg/mL contra M. avium e M. tuberculosis, respectivamente. Os derivados 2-6 obtidos por síntese parcial possuem diferentes substituintes nos carbonos 9 e 9 ', que alteram polaridade, solubilidade e limitam as rotações livres entre C8-C8' em relação de material (1) de partida. As diferenças estruturais entre estes compostos podem fornecer informações importantes sobre a relação estrutura-atividade antimicobacteriana do esqueleto dibenzilbutanodioico, obtido a partir de fonte natural, como um possível alvo para o desenvolvimento de drogas mais potentes contra a tuberculose

ABSTRACT: Evaluation of antimycobacterial activity of dihydrocubebin lignan extracted from Piper cubeba and its semisynthetic derivatives. The antimycobacterial activity of the dihydrocubebin (1), a dibenzylbutanedioiclignan obtained from ethanolic extract of Piper cubeba seeds, and its derivatives were examined in vitro against three different strains of Mycobacterium using amicrodilution method. Among the lignans evaluated, the 3 and 4 samples were the most active ones, displaying MIC values of 62.5 µg/mL against M. avium and M. tuberculosis, respectively. The derivatives 2-6, obtained for partial synthesis, had different substituents in the carbons 9 and 9', fact thatalters the polarity, solubility and restricts the free rotations between the bonds C8-C8' in relation to the starting material (1). The structural differences among these compounds provide important information about the antimycobacterial structure-activity relationship of the dibenzylbutanodioic skeleton, obtained from natural source, such as a possible target for the development of more powerful drugs against tuberculosis

[Identification of some Piper crude drugs based on Fourier transform infrared spectrometry].

The common peak ratio and variant peak ratio were calculated by FTIR spectroscopy of seven medicinal plants of Piper. The dual index sequence of common peak ratio and variant peak ratio was established, which showed the sibship of the medicinal plants. The common peak ratio of Piper kadsura (Choisy) Ohwi, Piper wallichii (Miq.) Hand.-Mazz. Piper laetispicum (C. DC.) was greater than 77%, and the variant peak ratio was less than 30%. The results showed the near sibship between the three drugs. The common peak ratio of Piper kadsura (Choisy) Ohwi, Piper nigrum L. and Piper boehmeriae folium Wall (Miq.) C. DC. Var. tonkinense (C. DC.) was about 61% which showed the farther sibship. The common peak ratio of Piper kadsura (Choisy) Ohwi and Piper betle (Linn.) was only 44%, which showed the farthest sibship. Piper kadsura (choisy) Ohwi and its adulterants, such as Piper wallichii (Miq.) Hand. -Mazz., Piper boehmeriaefolium Wall (Miq.) C. DC. Var. tonkinense C. DC. , Piper laetispicum C. DC., Piper nigrum L., could be identified by comparing their second order derivative IR spectrum of the samples. FTIR technique is a non-destructive analysis method which provides information of functional group, type and hydrogen bond without complex pretreatment procedures such as extraction and separatioin. FTIR method has some characteristics such as rapid and simple analysis procedure, good reproducibility, non-destructive testing, few amount of required sample and low cost and is environment-friendly. The method solved the problems of limit in resource of Piper kadsura (Choisy) Ohwi, many fakes and difficulties in identification, and brought the security for the clinical medication. FTIR provides a new method for identification of Piper kadsura (choisy) Ohwi and its fakes and meets the requirement for comprehensive analy sis and global analysis of traditional Chinese medicine.

Occurrence of piperidine alkaloids in Piper species collected in different areas.

A simple and convenient method was established for simultaneous quantitative determination of piperine and piperlonguminine in dried fruits of Piper longum and allied plants. The average content of piperine in P. longum (18.26 mg/g, range 12.05-33.23 mg/g) was about one half that of P. nigrum (40.09 mg/g, range 29.57-54.23 mg/g), but the content of piperlonguminine in P. longum was in the range of 0.42-1.82 mg/g, and the average content of piperlonguminne (0.91 mg/g) was about seven times higher than that in P. nigrum (0.13 mg/g). A sample of P. longum from Vietnam and a sample of P. retrofractum collected in Ishigaki, Japan, showed high contents of piperine and piperlonguminine. On the other hand, a sample of P. betle collected in Taiwan showed low content of piperine, and piperlonguminine was not detected.

Ação de extratos de plantas medicinais sobre a motilidade do trato gastrointestinal / Action of medicinal plant extracts on the gastrointestinal tract motility

Muitas plantas são utilizadas pela população para o tratamento e a cura de doenças. Entre elas encontram-se a Persea major Kopp, Piper mollicomum Kunth. e Serjania erecta Radlk. as quais são utilizadas para diversas enfermidades, inclusive para tratar distúrbios do trato gastrointestinal. O objetivo deste trabalho foi estudar os efeitos dos extratos dessas três plantas sobre a motilidade gastrointestinal. Camundongos Swiss foram tratados com os extratos pela via oral 1 hora antes da administração de uma solução semisólida de carboximetilcelulose 1,5% e vermelho de fenol 0,05% e, após 15 minutos, o esvaziamento gástrico e o trânsito intestinal avaliados. O extrato hidroalcoólico da P. major (100 a 1000 mg Kg-1, p.o.) e o extrato hidroalcoólico da P. mollicomum (100 e 300 mg Kg-1, p.o.) aumentaram o trânsito intestinal. No entanto, somente o extrato da P. major (100 e 300 mg Kg-1) também aumentou o esvaziamento gástrico. O extrato etanólico da S. erecta (100 a 1000 mg Kg-1, p.o.) não alterou a motilidade gastrointestinal. Estes resultados sugerem que a Persea major e a Piper mollicomum mereçam estudos mais aprofundados em busca de princípios ativos ou matéria vegetal efetiva para o tratamento de distúrbios do trato gastrointestinal como a constipação.

Many plants are popularly used for the treatment and healing of diseases. The Persea major Kopp, Piper mollicomum Kunth. and Serjania erecta Radlk. are used in several illnesses, including the treatment of disorders of the gastrointestinal tract. The aim of this study was to evaluate the effects of the extracts of these plants on the gastrointestinal motility. Swiss mice were orally treated with extracts one hour before the administration of a semisolid solution of 1.5% carboxymethylcellulose and 0.05% phenol red. After 15 minutes, the gastric emptying and intestinal transit were determined. The hydroalcoholic extract of P. major (100 to 1000 mg Kg-1, p.o.) and the hydroalcoholic extract of P. mollicomum (100 and 300 mg Kg-1, p.o.) increased the intestinal transit. However, only the P. major extract (100 and 300 mg Kg-1) increased the gastric emptying. The ethanolic extract of S. erecta (100 to 1000 mg Kg-1, p.o.) did not alter the gastrointestinal motility. These results suggest that Persea major and Piper mollicomum can be of interest for further studies in the search of active principles or effective plant material for the treatment of disorders of the gastrointestinal tract, such as constipation.

A comparison of leaf crystal macropatterns in the two sister genera Piper and Peperomia (Piperaceae).

PREMISE OF THE STUDY: This is the first large-scale study comparing leaf crystal macropatterns of the species-rich sister genera Piper and Peperomia. It focuses on identifying types of calcium oxalate crystals and their macropatterns in leaves of both genera. The Piper results are placed in a phylogenetic context to show evolutionary patterns. This information will expand knowledge about crystals and provide specific examples to help study their form and function. One example is the first-time observation of Piper crystal sand tumbling in chlorenchyma vacuoles. METHODS: Herbarium and fresh leaves were cleared of cytoplasmic content and examined with polarizing microscopy to identify types of crystals and their macropatterns. Selected hydrated herbarium and fresh leaf punches were processed for scanning electron microscopy and x-ray elemental analysis. Vibratome sections of living Piper and Peperomia leaves were observed for anatomical features and crystal movement. KEY RESULTS: Both genera have different leaf anatomies. Piper displays four crystal types in chlorenchyma-crystal sand, raphides, styloids, and druses, whereas Peperomia displays three types-druses, raphides, and prisms. Because of different leaf anatomies and crystal types between the genera, macropatterns are completely different. Crystal macropattern evolution in both is characterized by increasing complexity, and both may use their crystals for light gathering and reflection for efficient photosynthesis under low-intensity light environments. CONCLUSIONS: Both genera have different leaf anatomies, types of crystals and crystal macropatterns. Based on Piper crystals associated with photosynthetic tissues and low-intensity light, further study of their function and association with surrounding chloroplasts is warranted, especially active crystal movement.

Evaluation of genetic diversity in Piper spp using RAPD and SRAP markers.

Random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analysis were applied to 74 individual plants of Piper spp in Hainan Island. The results showed that the SRAP technique may be more informative and more efficient and effective for studying genetic diversity of Piper spp than the RAPD technique. The overall level of genetic diversity among Piper spp in Hainan was relatively high, with the mean Shannon diversity index being 0.2822 and 0.2909, and the mean Nei's genetic diversity being 0.1880 and 0.1947, calculated with RAPD and SRAP data, respectively. The ranges of the genetic similarity coefficient were 0.486-0.991 and 0.520-1.000 for 74 individual plants of Piper spp (the mean genetic distance was 0.505 and 0.480) and the within-species genetic distance ranged from 0.063 to 0.291 and from 0.096 to 0.234, estimated with RAPD and SRAP data, respectively. These genetic indices indicated that these species are closely related genetically. The dendrogram generated with the RAPD markers was topologically different from the dendrogram based on SRAP markers, but the SRAP technique clearly distinguished all Piper spp from each other. Evaluation of genetic variation levels of six populations showed that the effective number of alleles, Nei's gene diversity and the Shannon information index within Jianfengling and Diaoluoshan populations are higher than those elsewhere; consequently conservation of wild resources of Piper in these two regions should have priority.

Comparative analysis of pepper and tomato reveals euchromatin expansion of pepper genome caused by differential accumulation of Ty3/Gypsy-like elements.

BACKGROUND: Among the Solanaceae plants, the pepper genome is three times larger than that of tomato. Although the gene repertoire and gene order of both species are well conserved, the cause of the genome-size difference is not known. To determine the causes for the expansion of pepper euchromatic regions, we compared the pepper genome to that of tomato. RESULTS: For sequence-level analysis, we generated 35.6 Mb of pepper genomic sequences from euchromatin enriched 1,245 pepper BAC clones. The comparative analysis of orthologous gene-rich regions between both species revealed insertion of transposons exclusively in the pepper sequences, maintaining the gene order and content. The most common type of the transposon found was the LTR retrotransposon. Phylogenetic comparison of the LTR retrotransposons revealed that two groups of Ty3/Gypsy-like elements (Tat and Athila) were overly accumulated in the pepper genome. The FISH analysis of the pepper Tat elements showed a random distribution in heterochromatic and euchromatic regions, whereas the tomato Tat elements showed heterochromatin-preferential accumulation. CONCLUSIONS: Compared to tomato pepper euchromatin doubled its size by differential accumulation of a specific group of Ty3/Gypsy-like elements. Our results could provide an insight on the mechanism of genome evolution in the Solanaceae family.

Synergistic effects of amides from two piper species on generalist and specialist herbivores.

Plants use a diverse mix of defenses against herbivores, including multiple secondary metabolites, which often affect herbivores synergistically. Chemical defenses also can affect natural enemies of herbivores via limiting herbivore populations or by affecting herbivore resistance to parasitoids. In this study, we performed feeding experiments to examine the synergistic effects of imides and amides (hereafter "amides") from Piper cenocladum and P. imperiale on specialist (Eois nympha, Geometridae) and generalist (Spodoptera frugiperda, Noctuidae) lepidopteran larvae. Each Piper species has three unique amides, and in each experiment, larvae were fed diets containing different concentrations of single amides or combinations of the three. The amides from P. imperiale had negative synergistic effects on generalist survival and specialist pupal mass, but had no effect on specialist survival. Piper cenocladum amides also acted synergistically to increase mortality caused by parasitoids, and the direct negative effects of mixtures on parasitoid resistance and pupal mass were stronger than indirect effects via changes in growth rate and approximate digestibility. Our results are consistent with plant defense theory that predicts different effects of plant chemistry on generalist versus adapted specialist herbivores. The toxicity of Piper amide mixtures to generalist herbivores are standard bottom-up effects, while specialists experienced the top-down mediated effect of mixtures causing reduced parasitoid resistance and associated decreases in pupal mass.

Inter- and intraspecific comparisons of antiherbivore defenses in three species of rainforest understory shrubs.

Plants defend themselves against herbivores and pathogens with a suite of morphological, phenological, biochemical, and biotic defenses, each of which is presumably costly. The best studied are allocation costs that involve trade-offs in investment of resources to defense versus other plant functions. Decreases in growth or reproductive effort are the costs most often associated with antiherbivore defenses, but trade-offs among different defenses may also occur within a single plant species. We examined trade-offs among defenses in closely related tropical rain forest shrubs (Piper cenocladum, P. imperiale, and P. melanocladum) that possess different combinations of three types of defense: ant mutualists, secondary compounds, and leaf toughness. We also examined the effectiveness of different defenses and suites of defenses against the most abundant generalist and specialist Piper herbivores. For all species examined, leaf toughness was the most effective defense, with the toughest species, P. melanocladum, receiving the lowest incidence of total herbivory, and the least tough species, P. imperiale, receiving the highest incidence. Although variation in toughness within each species was substantial, there were no intraspecific relationships between toughness and herbivory. In other Piper studies, chemical and biotic defenses had strong intraspecific negative correlations with herbivory. A wide variety of defensive mechanisms was quantified in the three Piper species studied, ranging from low concentrations of chemical defenses in P. imperiale to a complex suite of defenses in P. cenocladum that includes ant mutualists, secondary metabolites, and moderate toughness. Ecological costs were evident for the array of defensive mechanisms within these Piper species, and the differences in defensive strategies among species may represent evolutionary trade-offs between costly defenses.

Enzymatic and non-enzymatic antioxidants in selected Piper species.

Piper species, commonly used in diet and traditional medicine were assessed for their antioxidant potential. Catalase activity was predominated in Piper longum, followed by Piper cubeba, green pepper, Piper brachystachyum and Piper nigrum. P. nigrum was richest in glutathione peroxidase and glucose-6-phosphate dehydrogenase, green pepper was richest in peroxidase and vitamin C while vitamin E was more in P. longum and P. nigrum. P. brachystachyum and P. longum were rich sources of vitamin A. All the Piper species had GSH content of around 1 to 2 nM/g tissue. The antioxidant components of Piper species constitute a very efficient system in scavenging a wide variety of reactive oxygen species. Antioxidant potential of Piper species was further confirmed by their ability to curtail in vitro lipid peroxidation by around 30-50% with concomitant increase in GSH content.