Plant antiherbivore defenses in Fabaceae species of the Chaco

Abstract

The establishment and maintenance of plant species in the Chaco, one of the widest continuous areas of forests in the South American with sharp climatic variations, are possibly related to biological features favoring plants with particular defenses. This study assesses the physical and chemical defenses mechanisms against herbivores of vegetative and reproductive organs. Its analyses of 12 species of Fabaceae (Leguminosae) collected in remnants of Brazilian Chaco shows that 75% present structural defense characters and 50% have chemical defense -defense proteins in their seeds, like protease inhibitors and lectins. Physical defenses occur mainly on branches (78% of the species), leaves (67%), and reproductive organs (56%). The most common physical characters are trichomes and thorns, whose color represents a cryptic character since it does not contrast with the other plant structures. Defense proteins occur in different concentrations and molecular weight classes in the seeds of most species. Protease inhibitors are reported for the first time in seeds of: Albizia niopoides, Anadenanthera colubrina, Mimosa glutinosa, Prosopis rubriflora, and Poincianella pluviosa. The occurrence of physical and chemical defenses in members of Fabaceae indicate no associations between defense characters in these plant species of the Chaco.Keywords: structural characters, protease inhibitors, lectins, defense mechanisms. Defesas das plantas anti-herbivoria em espécies de Fabaceae do Chaco ResumoO estabelecimento e a manutenção de espécies no Chaco, uma planície semi-árida da América do Sul com variações climáticas importantes, possivelmente estão relacionados a características biológicas que favorecem as plantas detentoras de defesas particulares. Este estudo teve como objetivos avaliar os mecanismos de defesa física e química anti-herbivoria em órgãos vegetativos e reprodutivos. Analisamos 12 espécies da família Fabaceae (Leguminosae) obtidas em remanescentes de Chaco brasileiro. Observamos que 75% das espécies estudadas apresentam atributo de defesa física e 50% possuem defesa química -proteínas de defesa nas sementes, como inibidores de protease e lectinas. As defesas físicas ocorrem principalmente nos ramos (78% das espécies), nos órgãos reprodutivos (56% das espécies) e nas folhas (67%). Os atributos físicos mais frequentes são tricomas e espinhos, cuja coloração não contrastante com as demais estruturas das plantas representa um caráter críptico. Proteínas de defesa ocorrem nas sementes da maioria das espécies, com diferentes concentrações e classes de pesos moleculares. Inibidores de protease nas sementes estão sendo relatados pela primeira vez em: Albizia niopoides, Anadenanthera colubrina, Mimosa glutinosa, Prosopis rubriflora e Poincianella pluviosa. A ocorrência de defesas física e química entre os membros de Fabaceae indica que não há associações entre as características de defesa das espécies de plantas avaliadas no Chaco.Palavras-chave: características estruturais, inibidores de protease, lectinas, mecanismo...

Glandular trichomes of Robinia viscosa Vent. var. hartwigii (Koehne) Ashe (Faboideae, Fabaceae)—morphology, histochemistry and ultrastructure

“…toxic tannins accumulated in trichome cells and other alkaloid-reinforced polyphenols. Peter et al (1995) and Lima et al (2017) have identified three types of action of Fabaceae trichomes as an insect-resistance mechanism: (i) a physical barrier limiting the contact between the plant and insects, (ii) production of toxic metabolites poisoning insects upon contact with the secretion, and (iii) production of viscous secretory compounds on the plant surface to immobilise insects. As indicated by our observations, all these mechanisms of triple protection of plants against pests operate in Hartweg's locust.…”

Genetic Transformation in Agro-Economically Important Legumes

“…On its own, climate change continues to threaten the metabolic productivity of legumes and other equally important crops. Problems, such as biological invasion at planting fields, have become exacerbated, leading to the infection of legume plants by bacterial, viral, fungal, and insect pathogens [27][28][29]. These pathogens cause diseases, such as wilt and blight, which have a negative impact on the production of quality crops.…”

Plant Lectins with Insecticidal and Insectistatic Activities

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