Alterações morfológicas e fisiológicas na estrutura vegetativa de Bulbostylis paradoxa associadas ao seu rápido florescimento no pós fogo
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Data
2021-12-14
Autores
Rosalem, Patrícia Fernanda
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Universidade Estadual Paulista (Unesp)
Resumo
As espécies encontradas em ambientes propensos ao fogo apresentam características adaptativas tanto fisiológicas quanto anatômicas e morfológicas. Tais adaptações garantem o sucesso de sua sobrevivência. Bulbostylis paradoxa uma Cyperaceae da América do Sul, apresenta uma forma vegetativa diferente das demais espécies do próprio gênero e chama atenção por seu rápido florescimento pós fogo. Tendo em vista tais características marcantes, o presente estudo teve como objetivo analisar as características anatômicas e fisiológicas de B. paradoxa e investigar alterações nos dias seguintes ao fogo, através de comparações entre presença e ausência de fogo. Investigando a capacidade protetiva dos órgãos e reservas através de parâmetros morfofisiológicos e quantificando compostos ligados à reserva e mobilização destas, como amido, carboidratos solúveis, aminoácidos e proteínas. O material foi coletado no Cerrado, na Reserva Natural Serra do Tombador, em Goiás. Foram coletados indivíduos Controle (não queimados), 24 horas, 48 horas e 15 dias após o fogo. Foram amostrados para fisiologia e anatomia folha, caudex, raiz e flores. Para fisiologia foram quantificados amido, aminoácidos, carboidratos solúveis e proteínas. Para anatomia, foram confeccionadas lâminas que foram coradas em Azul de Toluidina, e testes histoquímicos para verificar outras substâncias. Também foram feitas análises em Microscopia Eletrônica de Varredura (MEV). Das reservas quantificadas, observamos aumento de amido e carboidratos com as queimas, em todas as partes da planta. Para os aminoácidos, observamos aumento na concentração nas flores dos indivíduos queimados bianualmente 48h após o fogo. E a concentração de proteínas mostrou diminuição nas flores queimadas. Quanto a anatomia, encontramos lignina nas folhas, em toda a epiderme e em uma das bainhas que envolvem o feixe vascular, podendo indicar alta proteção para o órgão foliar. Foram encontrados grãos de amido no parênquima das folhas, no parênquima do cilindro vascular do caudex e no periciclo das raízes mais distantes do caudex. As substâncias pécticas foram evidenciadas nas paredes celulares da folha, do caudex e da raiz. E leves reações de proteínas foram detectadas nas paredes celulares dos tecidos do caudex e raiz. Também foram observados compostos fenólicos no caudex dentro cilindro vascular e nas células do córtex e de revestimento. E os resultados obtidos com a MEV mostraram os estômatos dispostos em fileira. Assim concluímos que a queima causou alterações no metabolismo de reservas de B. paradoxa, porém sua estrutura anatômica permaneceu intacta.
Species found in fire-prone environments have both physiological, anatomical and morphological adaptive traits. Such adaptations ensure the success of their survival. Bulbostylis paradoxa a Cyperaceae from South America presents a vegetative form that is different from the other species of the genus and attract attention for its rapid flowering after fire. In view of such remarkable traits, the present study aimed to analyze the anatomical and physiological traits of B. paradoxa and investigate changes in the days following a precribed fire, through comparisons between the presence and without fire. We investigated the protective capacity of organs and reserves through morphophysiological parameters and quantified compounds linked to their reserve and its mobilization, such as starch, soluble carbohydrates, amino acids, and proteins accumulation. The sampling was performed in the in the Cerrado, in the Serra do Tombador Nature Reserve, in Goiás. Individuals were sample under the following conditions: control, 24 hours, 48 hours and 15 days after fire. Leaf, caudex, root and flower physiology and anatomy were examined. For physiology, starch, amino acids, soluble carbohydrates and proteins were quantified. For anatomy, slides were made and stained in Toluidine Blue, and histochemical tests were performed to check other substances. Scanning Electron Microscopy (SEM) analyzes were also performed. For the quantified reserves, we observed an increase in starch and carbohydrates with burning, in all parts of the plant. For amino acids, we observed an increase in the concentration in the flowers of individuals burned biannually 48h after fire. And the protein concentration showed a decrease in burned flowers. For anatomy, we found lignin in the leaves, throughout the epidermis and in one of the vascular bundle sheaths, which may indicate high protection for the leaf organ. Starch grains were found in the parenchyma of leaves, in the parenchyma of the vascular cylinder of the caudex and in the pericycle of the roots farthest from the caudex. Pectic substances were evidenced in the cell walls of the leaf, the caudex and the root. Phenolic compounds were also observed in the caudex within the vascular cylinder and in the cortex and coating cells. And the results obtained with the SEM showed the stomata arranged in line. We concluded that the burning caused alterations in the metabolism of reserves of B. paradoxa, but its anatomical structure remained intact.
Species found in fire-prone environments have both physiological, anatomical and morphological adaptive traits. Such adaptations ensure the success of their survival. Bulbostylis paradoxa a Cyperaceae from South America presents a vegetative form that is different from the other species of the genus and attract attention for its rapid flowering after fire. In view of such remarkable traits, the present study aimed to analyze the anatomical and physiological traits of B. paradoxa and investigate changes in the days following a precribed fire, through comparisons between the presence and without fire. We investigated the protective capacity of organs and reserves through morphophysiological parameters and quantified compounds linked to their reserve and its mobilization, such as starch, soluble carbohydrates, amino acids, and proteins accumulation. The sampling was performed in the in the Cerrado, in the Serra do Tombador Nature Reserve, in Goiás. Individuals were sample under the following conditions: control, 24 hours, 48 hours and 15 days after fire. Leaf, caudex, root and flower physiology and anatomy were examined. For physiology, starch, amino acids, soluble carbohydrates and proteins were quantified. For anatomy, slides were made and stained in Toluidine Blue, and histochemical tests were performed to check other substances. Scanning Electron Microscopy (SEM) analyzes were also performed. For the quantified reserves, we observed an increase in starch and carbohydrates with burning, in all parts of the plant. For amino acids, we observed an increase in the concentration in the flowers of individuals burned biannually 48h after fire. And the protein concentration showed a decrease in burned flowers. For anatomy, we found lignin in the leaves, throughout the epidermis and in one of the vascular bundle sheaths, which may indicate high protection for the leaf organ. Starch grains were found in the parenchyma of leaves, in the parenchyma of the vascular cylinder of the caudex and in the pericycle of the roots farthest from the caudex. Pectic substances were evidenced in the cell walls of the leaf, the caudex and the root. Phenolic compounds were also observed in the caudex within the vascular cylinder and in the cortex and coating cells. And the results obtained with the SEM showed the stomata arranged in line. We concluded that the burning caused alterations in the metabolism of reserves of B. paradoxa, but its anatomical structure remained intact.
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Palavras-chave
Cyperaceae, Alterações morfofisiológicas, Fogo, Estruturas morfoanatômicas, Metabolismo vegetal, Fire, Morphoanatomical structures, Morphophysiological changes, Plant metabolism