29 research outputs found

    Insect Eggs Can Enhance Wound Response in Plants: A Study System of Tomato Solanum lycopersicum L. and Helicoverpa zea Boddie

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    Insect oviposition on plants frequently precedes herbivory. Accumulating evidence indicates that plants recognize insect oviposition and elicit direct or indirect defenses to reduce the pressure of future herbivory. Most of the oviposition-triggered plant defenses described thus far remove eggs or keep them away from the host plant or their desirable feeding sites. Here, we report induction of antiherbivore defense by insect oviposition which targets newly hatched larvae, not the eggs, in the system of tomato Solanum lycopersicum L., and tomato fruitworm moth Helicoverpa zea Boddie. When tomato plants were oviposited by H. zea moths, pin2, a highly inducible gene encoding protease inhibitor2, which is a representative defense protein against herbivorous arthropods, was expressed at significantly higher level at the oviposition site than surrounding tissues, and expression decreased with distance away from the site of oviposition. Moreover, more eggs resulted in higher pin2 expression in leaves, and both fertilized and unfertilized eggs induced pin2 expression. Notably, when quantified daily following deposition of eggs, pin2 expression at the oviposition site was highest just before the emergence of larvae. Furthermore, H. zea oviposition primed the wound-induced increase of pin2 transcription and a burst of jasmonic acid (JA); tomato plants previously exposed to H. zea oviposition showed significantly stronger induction of pin2 and higher production of JA upon subsequent simulated herbivory than without oviposition. Our results suggest that tomato plants recognize H. zea oviposition as a signal of impending future herbivory and induce defenses to prepare for this herbivory by newly hatched neonate larvae

    Risks to pollinators and pollination from invasive alien species

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    Invasive alien species modify pollinator biodiversity and the services they provide that underpin ecosystem function and human well-being. Building on the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) global assessment of pollinators and pollination, we synthesize current understanding of invasive alien impacts on pollinators and pollination. Invasive alien species create risks and opportunities for pollinator nutrition, re-organize species interactions to affect native pollination and community stability, and spread and select for virulent diseases. Risks are complex but substantial, and depend greatly on the ecological function and evolutionary history of both the invader and the recipient ecosystem. We highlight evolutionary implications for pollination from invasive alien species, and identify future research directions, key messages and options for decision-making

    Perception, signaling and molecular basis of oviposition-mediated plant responses.

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    Eggs deposited on plants by herbivorous insects represent a threat as they develop into feeding larvae. Plants are not a passive substrate and have evolved sophisticated mechanisms to detect eggs and induce direct and indirect defenses. Recent years have seen exciting development in molecular aspects of egg-induced responses. Some egg-associated elicitors have been identified, and signaling pathways and egg-induced expression profiles are being uncovered. Depending on the mode of oviposition, both the jasmonic acid and salicylic acid pathways seem to play a role in the induction of defense responses. An emerging concept is that eggs are recognized like microbial pathogens and innate immune responses are triggered. In addition, some eggs contain elicitors that induce highly specific defenses in plants. Examples of egg-induced suppression of defense or, on the contrary, egg-induced resistance highlight the complexity of plant-egg interactions in an on-going arms race between herbivores and their hosts. A major challenge is to identify plant receptors for egg-associated elicitors, to assess the specificity of these elicitors and to identify molecular components that underlie various responses to oviposition

    Linfangioleiomiomatose pulmonar Pulmonary Lymphangioleiomyomatosis

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    Linfangioleiomiomatose pulmonar (LAM) Ă© uma doença rara, de etiologia desconhecida, que basicamente afeta mulheres jovens no perĂ­odo fĂ©rtil de sua vida. Clinicamente, manifesta-se atravĂ©s de dispnĂ©ia progressiva, pneumotĂłrax de repetição, tosse seca e, menos freqĂŒentemente, por quilotĂłrax e escarros hemoptĂłicos. Essas alteraçÔes surgem devido Ă  proliferação anormal de cĂ©lulas de mĂșsculo liso no parĂȘnquima pulmonar, linfonodos e em outros tecidos. Mais recentemente, estudos citogenĂ©ticos verificaram a presença de mutaçÔes do gene TSC-2 em cĂ©lulas de angiomiolipoma renal e linfonodos abdominais de pacientes com LAM, indicando uma possĂ­vel origem para as lesĂ”es hamartomatosas da doença. Radiologicamente, caracteriza-se pela presença de infiltrado intersticial reticulonodular e sinais de hiperinsuflação ao radiografia de tĂłrax. Na tomografia computadorizada de alta resolução, cistos de paredes finas, localizados centralmente, sĂŁo visibilizados por todo o parĂȘnquima do pulmĂŁo. O ultrassom e a tomografia de abdome podem revelar angiomiolipomas renais e linfonodomegalias retroperitoneais. Meningeomas tambĂ©m podem estar associados, porĂ©m a sua presença deve sempre levar Ă  pesquisa de esclerose tuberosa. Funcionalmente, a doença caracteriza-se por um distĂșrbio ventilatĂłrio obstrutivo, de carĂĄter progressivo, com hiperinsuflação pulmonar e diminuição da difusĂŁo de monĂłxido de carbono. Apesar da ausĂȘncia de comprovação quanto Ă  eficĂĄcia, o principal tratamento utilizado ainda Ă© o anti-estrogĂȘnico e constitui-se de oofarectomia, progesterona contĂ­nua, tamoxifeno e anĂĄlogos de GnRH. AlĂ©m desse, a realização de transplantes pulmonares tem elevado para alĂ©m de dez anos a sobrevida mĂ©dia das pacientes.<br>Lymphangioleiomyomatosis (LAM) is a rare lung disease of unkwnon etiology that frequently affects women in childbearing age. Clinically it manifests itself by and pneumothorax. Chylous pleural effusions and hemoptisis occur less frenquently. All these fenomena results from the abnormal smooth muscle proliferation in the lung parenchima. Lymph-nodes, small airways and blood vessels. More recently cytogenetic studies disclosed mutations of the TSC-2 gene in cells of renal angiomyolipoma and/or abdominal lymph nodes, pointing towards a possible origin of the hamartomatous lesions. Chest radiography may appear normal or yield reticulonodular infiltrates and signs of hyperinsuflation. At HRCT scans, multiple thin-walled cysts can be seen over the lung parenchyma. Abdominal imaging by either ultrasound or CT may show renal angiomyolipomas and retroperitoneal lymph node enlargement. Meningeomas may also be associated but their presence requires testing for tuberous sclerosis complex. Physiologically LAM is characterized by progressive airflow obstruction, air trapping and gastransfer impairment. Estrogenic suppression with either oophorectomy, deposit progestogens, tamoxifen and GnRh analogs, is still the main treatment. In addition to this therapy lung transplantations have increased patients median survival rates by more than ten years
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