Development of the ovule and seed of Habanero chili pepper (Capsicum chinense Jacq.): Anatomical characterization and immunocytochemical patterns of pectin methyl-esterification.

Ovule and seed development in plants has long fascinated the scientific community given the complex cell coordination implicated in these processes. These cell events are highly conserved but are not necessarily representative of all plants. In this study, with the aim of obtaining information regarding the cellular patterns that follow the usual development of the ovule and the zygotic embryo, we carried out an integral anatomical study of the Capsicum chinense Jacq., floral buds and seeds at various days during maturation. This study allowed us to identify the main histo-morphological stages accompanying the transition of somatic cells into the macrospore, female gamete, and the zygotic embryogenesis. This knowledge is fundamental for future biotechnological research focused on solving the morphological recalcitrance observed during the in vitro induction of somatic or microspore embryogenesis in Capsicum. For the first time in C. chinense, we have described the hypostases, a putative source of plant growth regulators, and "the corrosion cavity", a space around the embryo. Additionally, the cell wall pectin-esterification status was investigated by immunohistology. At early stages of morphogenesis, the pectin is highly methyl-esterified; however, methyl-esterification decreases gradually throughout the process. A comparison of the results obtained here, together with the histo- and immunological changes occurring during the somatic and microspore embryogenesis, should help to elucidate the biochemical mechanisms that trigger the morphogenic events in Capsicum spp.

Developmental landmarks during floral ontogeny of jalapeño chili pepper (Capsicum annuum L.) and the effect of gibberellin on ovary growth.

Pepper (Capsicum annuum L.) is an important horticultural crop in many regions of the world. The final shape and size of the fruit are known to be determined at a very early step of flower development. During flower development hormonal treatments using gibberellins seem to promote growth resulting in higher yield and fruit quality. However, the morphological changes that occur in the pepper flowers after these treatments are largely unknown. In the present study, we provide a description of floral development landmarks of jalapeño chili pepper (cultivar Huichol), divided in nine representative stages from its initiation until the opening of the bud. We established a correlation among external flower development and the time and pattern of reproductive organogenesis. Male and female gametogenesis progression was used to define specific landmarks during flower maturation. The pattern of expression of key genes involved in gibberellin metabolism and response was also evaluated in the nine flower stages. The proposed development framework was used to analyze the effect of gibberellin treatments in the development of the flower. We observed both an effect of the treatment in the histology of the ovary tissue and an increase in the level of expression of CaGA2ox1 and CaGID1b genes. The developmental stages we defined for this species are very useful to analyze the molecular and morphological changes after hormonal treatments.

Pimentas do gênero Capsicum: propriedades e ações terapéuticas / Pimientos del género Capsicum: propiedades y acciones terapéuticas / Capsicum peppers: properties and therapeutic actions

As especies do genero Capsicum L. vem sendo estudadas por pesquisadores do mundo inteiro. A pungencia e o atributo principal das pimentas e as substancias responséveis por esta ardencia sao denominadas de capsaicinoides. O mais estudado ea capsaicina, sua rota biossintetica e atraves da via dos fenilpropanoides e écidos graxos. A capsaicina e um agonista exogeno do receptor TRPV1(transient receptor potential vanilloid type-7). O TRPV1 contem uma subunidade sensivel ao calor responsével pela sensaçao de queimadura causada pela capsaicina. Quando aplicada na pele, promove uma resposta analgesica devido a dessensibilizaçao dos neuronios sensoriais causados pelo esgotamento da substancia P. A meia vida da capsaicina e vinte e quatro horas quando utilizada por via oral. Sua concentraçao maxima atinge o figado, rins e intestino ern uma hora apos administraçao oral. A capsaicina e principalmente eliminada pelos rins, com uma pequena proporçao nao transformada excretada nas fezes e na urina. Na aplicagao topica, a biotransformaçao da capsaicina foi considerada lenta e a maior parte da mesma permaneceu inalterada. A capsaicina e seus anélogos tem sido utilizados em cremes e patches para tratar sindromes de dor cronica como neuralgia pos-herpetica, dores musculoesqueleticas, neuropatia diabetica, osteoartrite e artrite reumatoide. A capsaicina tambem tem atividade antihiperlipidemica, propiedades anti-inflamatorias, antioxidantes e e efetiva no tratamento da dor associada com artrite e cistite. O capsiato, presente nas pimentas vermelhas nao pungentes tambem estimula o receptor TRPV1, sendo capaz de aumentar o metabolismo por estimulagao do sistema nervoso simpético, alem de ser provido de agao antiinflamatoria, porem por mecanismo ainda desconhecido (AU)

Las especies del género Capsicum, han sido estudiadas por los investigadores de todo el mundo. La pungencia es el principal atributo de los pimientos picantes y las sustancias responsables son los capsaicinoides. La capsaicina es la mas estudiada, su ruta biosintética es a través de la vía de fenilpropanoides y ácidos grasos. La capsaicina es un receptor TRPV1 agonista exógeno (receptor de potencial transitorio vaniloide tipo 1). El TRPV1 contiene una subunidad sensible al calor responsable de la sensación de ardor causada por la capsaicina. Cuando se aplica a la piel se promueve una respuesta analgésica debido a la desensibilización de las neuronas sensoriales causadas por el agotamiento de la sustancia P. La Vida media de la capsaicina es de 24 horas cuando se usa por via oral. Su distribución máxima alcanza el hígado, el riñón y el intestino en una hora después de la administración oral. La capsaicina se elimina principalmente por via renal, con una pequefia proporción no transformada excretada en las heces y en la orina. En la aplicación tópica de capsaicina la biotransformación se consideró lenta, y la mayor parte de la misma permaneció inalterada. La capsaicina y sus análogos han sido utilizados en cremas y apósitos para el tratamiento de síndromes de dolor crónico, tales como neuralgia postherpética, dolor musculo esquelético, neuropatía diabética, la osteoartritis y artritis reumatoide. La capsaicina también tiene actividad hipolipemiante, antiinflamatoria, antioxidante y es eficaz en el tratamiento del dolor asociado a artritis y cistitis. El capsiato, presente en pimientos rojos no picantes, también estimula el receptor TRPV1, siendo capaz de aumentar el metabolismo mediante la estimulación del sistema nervioso simpático, y presentando, además, acción antiinflamatoria, por un mecanismo aun desconocido (AU)

The species of the genus Capsicum have been studied by researchers worldwide. Pungency is the main attribute of peppers and it is due to the capsaicinoids. The most studied is capsaicin, biosynthetised through the phenylpropanoid and fatty acid pathway. Capsaicin is an exogenous agonist of TRPV1 receptor (transient receptor potential vanilloid type-1). The TRPV1 contains a subunit sensitive to heat, responsible for the burning sensation caused by capsaicin. When applied to the skin it promotes an analgesic response due to desensitization of sensory neurons caused by the depletion of substance P. The half-life of capsaicin is twenty-four hours when used orally. Its maximum concentration reaches the liver, kidney and intestine one hour after oral administration. Capsaicin is eliminated primarily by kidneys, with a small proportion of untransformed excreted in faeces and urine. After topical application, the biotransformation of capsaicin was considered slow, and it was mostly unchanged. Capsaicin and its analogues have been used in creams and patches to treat chronic pain syndromes, such as postherpetic neuralgia, musculoskeletal pain, diabetic neuropathy, osteoarthritis and rheumatoid arthritis. Capsaicin also has antihyperlipidemic, anti-inflammatory and antioxidant activities, being effective in the treatment of pain associated with arthritis and cystitis. The capsiate, present in non-pungent red peppers, also stimulates the TRPV1 receptor, being able to increase metabolism by stimulating the sympathetic nervous system, and showing, in addition, anti-inflammatory activity by a mechanism still unknown (AU)

CaMF2, an anther-specific lipid transfer protein (LTP) gene, affects pollen development in Capsicum annuum L.

Based on the gene differential expression analysis performed by cDNA-amplified fragment length polymorphism (cDNA-AFLP) in the genic male sterile-fertile line 114AB of Capsicum annuum L., a variety of differentially expressed cDNA fragments were detected in fertile or sterile lines. A transcript-derived fragment (TDF) specifically accumulated in the flower buds of fertile line was isolated, and the corresponding full-length cDNA and DNA were subsequently amplified. Bioinformatical analyses of this gene named CaMF2 showed that it encodes a lipid transfer protein with 94 amino acids. Spatial and temporal expression patterns analysis indicated that CaMF2 was an anther-specific gene and the expression of CaMF2 was detected only in flower buds at stage 3-7 of male fertile line with a peak expression at stage 4, but not detected in the roots, tender stems, fresh leaves, flower buds, open flowers, sepals, petals, anthers or pistils of male sterile line. Further, inhibition of the CaMF2 by virus-induced gene silencing (VIGS) method resulted in the low pollen germination ability and shriveled pollen grains. All these evidence showed that CaMF2 had a vital role in pollen development of C. annuum.

The antioxidant activity and polyphenolic contents of different plant seeds extracts.

Different plant seeds extracts of Citrus sinensis, Hordeum sativum, Triticum sativum, Canna indica, Citrullus vulgaris and Capsicum annuum were evaluated for their antioxidant activity by the following methods: 2,2-diphenyl-1-pycril-hydrazyl (DPPH) radical scavenging, reducing power, RBCs hemolysis and linoleic acid oxidation, a long with the determination of total phenolic and flavonoids contents. All the methanolic extracts showed high antioxidant activity and have high contents of phenolic and flavonoid. The Canna indica extract exhibited strong antioxidant as a reducing power and as DPPH radical-scavenging (3.61 absorbance, 87.12%, respectively), while the Hordeum sativum extract exhibited highest inhibitory effect on RBCs hemolysis (59.55%) and the Capsicum annuum extract has highest inhibitory effect on linoleic acid peroxidation (65.06%).

QTL analysis of plant development and fruit traits in pepper and performance of selective phenotyping.

A QTL analysis was performed to determine the genetic basis of 13 horticultural traits conditioning yield in pepper (Capsicum annuum). The mapping population was a large population of 297 recombinant inbred lines (RIL) originating from a cross between the large-fruited bell pepper cultivar 'Yolo Wonder' and the small-fruited chilli pepper 'Criollo de Morelos 334'. A total of 76 QTLs were detected for 13 fruit and plant traits, grouped in 28 chromosome regions. These QTLs explained together between 7% (internode growth time) and 91% (fruit diameter) of the phenotypic variation. The QTL analysis was also performed on two subsets of 141 and 93 RILs sampled using the MapPop software. The smaller populations allowed for the detection of a reduced set of QTLs and reduced the overall percentage of trait variation explained by QTLs. The frequency of false positives as well as the individual effect of QTLs increased in reduced population sets as a result of reduced sampling. The results from the QTL analysis permitted an overall glance over the genetic architecture of traits considered by breeders for selection. Colinearities between clusters of QTLs controlling fruit traits and/or plant development in distinct pepper species and in related solanaceous crop species (tomato and eggplant) suggests that shared mechanisms control the shape and growth of different organs throughout these species.

Identification of a third haplotype of the sequence linked to the Restorer-of-fertility (Rf) gene and its implications for male-sterility phenotypes in peppers (Capsicum annuum L.).

Cytoplasmic male sterility (CMS), one of the most important traits in crop breeding, has been used for commercial seed production by F1 hybrid cultivars of pepper (Capsicum annuum L.). To develop reliable molecular markers for allelic selection of the Restorer-of-fertility (Rf) gene, which is known to be a major determinant of pollen fertility restoration in peppers, a sequence of approximately 10 kb flanking an RAPD fragment closely linked to the Rf locus was obtained by genome walking. A homology search revealed that this sequence contained an LTR retrotransposon and a non-LTR LINE-like retrotransposon. Sequencing of this Rf-linked region to search for polymorphisms between a dominant and recessive allele revealed 98% nucleotide sequence identity between them. A third polymorphic haplotype of the Rf-linked sequence, which has 94-96% nucleotide sequence identity with the two previously isolated haplotypes, was identified among a large number of breeding lines. Utilizing polymorphic sequences in the haplotypes, PCR markers were developed for selection of particular haplotypes and used to examine the distribution of the haplotypes in diverse breeding lines, cultivars, and C. annuum germplasms. Surprisingly, the third haplotype was the predominant type in C. annuum germplasms, while its frequency in F1 hybrid cultivars was relatively low. Meanwhile, analysis of breeding lines whose Rf allele genotypes and male-sterility phenotypes were already known revealed that the third haplotype was mainly present in exotic breeding lines that cause unstable male-sterility when combined with sterile cytoplasms.

Anatomical features of pepper plants (Capsicum annuum L.) grown under red light-emitting diodes supplemented with blue or far-red light.

Pepper plants (Capsicum annuum L. cv., Hungarian Wax) were grown under metal halide (MH) lamps or light-emitting diode (LED) arrays with different spectra to determine the effects of light quality on plant anatomy of leaves and stems. One LED (660) array supplied 90% red light at 660 nm (25nm band-width at half-peak height) and 1% far-red light between 700-800nm. A second LED (660/735) array supplied 83% red light at 660nm and 17% far-red light at 735nm (25nm band-width at half-peak height). A third LED (660/blue) array supplied 98% red light at 660nm, 1% blue light between 350-550nm, and 1% far-red light between 700-800nm. Control plants were grown under broad spectrum metal halide lamps. Plants were gron at a mean photon flux (300-800nm) of 330 micromol m-2 s-1 under a 12 h day-night photoperiod. Significant anatomical changes in stem and leaf morphologies were observed in plants grown under the LED arrays compared to plants grown under the broad-spectrum MH lamp. Cross-sectional areas of pepper stems, thickness of secondary xylem, numbers of intraxylary phloem bundles in the periphery of stem pith tissues, leaf thickness, numbers of choloplasts per palisade mesophyll cell, and thickness of palisade and spongy mesophyll tissues were greatest in peppers grown under MH lamps, intermediate in plants grown under the 660/blue LED array, and lowest in peppers grown under the 660 or 660/735 LED arrays. Most anatomical features of pepper stems and leaves were similar among plants grown under 660 or 660/735 LED arrays. The effects of spectral quality on anatomical changes in stem and leaf tissues of peppers generally correlate to the amount of blue light present in the primary light source.