학술논문
SEASONAL PATTERNS OF PHENYLALANINE AMMONIA-LYASE ACTIVITY AND TOTAL PHENOL AND TANNIN CONTENTS IN Stryphnodendron adstringens (Mart.) Coville/AVALIACAO SAZONAL DA ATIVIDADE DA FENILALANINA AMONIA-LIASE E DOS TEORES DE FENOIS E TANINOS TOTAIS EM Stryphnodendron adstringens (Mart.) Coville
Document Type
Academic Journal
Author
Source
Ciencia Florestal. July-Sep, 2017, Vol. 27 Issue 3, p1037, 12 p.
Subject
Language
English
ISSN
1980-5098
Abstract
INTRODUCTION The Brazilian Cerrado represents the major savanna region in America and covered approximately 2 million [km.sup.2] of Brazil's territory. This formation occurs under a tropical semi-humid climate with pronounced [...]
There were performed analyses of the leaves and stem bark of Stryphnodendron adstringens, a Brazilian Cerrado plant, to examine the seasonal patterns of phenylalanine ammonia-lyase activity and total phenol and tannin contents in 16 adult individuals under field conditions. The measurements of gas exchange parameters, including net photosynthesis, transpiration and stomatal conductance, as well as the photosynthetic photon flux density, leaf temperature, vapor pressure deficit and leaf water potential were also performed. The results were subjected to a principal component analysis. The values obtained for stomatal conductance, net photosynthesis, transpiration, water use efficiency, minimum water potential and photosynthetic photon flux density were higher in the rainy season, while the maximum water potential and vapor pressure deficit in the atmosphere were similar between seasons. The seasonal variations in gas exchange characteristics were influenced by changing weather conditions and were positively correlated with higher air temperatures, rainfall amounts and relative air humidity and negatively correlated with increased insolation. There was no correlation between the maximum leaf water potential and any of the weather variables. Phenylalanine ammonia-lyase activity was similar in the dry and rainy seasons, and higher levels of total phenols and tannins were observed in the dry and rainy seasons, respectively. Phenylalanine ammonia-lyase activity and total phenol contents were negatively influenced by temperature and rainfall in the dry season, and the total tannin contents were mainly correlated with higher temperatures and a lower influence of rainfall in the rainy season. Keywords: gas exchange; Cerrado; phenolic compounds; seasonality. Folhas e cascas do caule de Stryphnodendron adstringens, uma especie do Cerrado brasileiro, foram utilizadas para examinar os padroes sazonais da atividade da fenilalanina amonia-liase e os teores de fenois e taninos totais em 16 individuos adultos, em condicoes de campo. Avaliacoes das trocas gasosas, incluindo fotossintese liquida, transpiracao, condutancia estomatica, densidade de fluxo de fotons fotossinteticamente ativos, temperatura da folha, deficit de pressao de vapor e potencial hidrico foliar foram realizadas. Os resultados foram submetidos a analise de componentes principais. A condutancia estomatica, fotossintese liquida, transpiracao, eficiencia do uso da agua, potencial hidrico minimo e densidade de fluxo de fotons fotossinteticamente ativos foram maiores na estacao chuvosa, enquanto que o potencial hidrico maximo e o deficit de pressao de vapor na atmosfera foram semelhantes entre as estacoes. As variacoes sazonais nas caracteristicas de trocas gasosas foram influenciadas por mudancas nas condicoes climaticas e se correlacionaram positivamente com as maiores temperaturas, precipitacao e umidade relativa do ar e negativamente com o aumento da insolacao. Nao houve correlacao entre o potencial hidrico foliar maximo e as demais variaveis climaticas. A atividade da fenilalanina amonia-liase foi semelhante nas estacoes seca e chuvosa e os maiores teores de fenois e taninos totais foram observados nas estacoes seca e chuvosa, respectivamente. A atividade da fenilalanina amonia-liase e os teores de fenois totais foram influenciados negativamente pela temperatura e precipitacao na estacao seca, e os teores de taninos totais foram correlacionados principalmente com temperaturas mais elevadas, com menor influencia da precipitacao na estacao chuvosa. Palavras-chave: trocas gasosas; Cerrado; compostos fenolicos; sazonalidade.
There were performed analyses of the leaves and stem bark of Stryphnodendron adstringens, a Brazilian Cerrado plant, to examine the seasonal patterns of phenylalanine ammonia-lyase activity and total phenol and tannin contents in 16 adult individuals under field conditions. The measurements of gas exchange parameters, including net photosynthesis, transpiration and stomatal conductance, as well as the photosynthetic photon flux density, leaf temperature, vapor pressure deficit and leaf water potential were also performed. The results were subjected to a principal component analysis. The values obtained for stomatal conductance, net photosynthesis, transpiration, water use efficiency, minimum water potential and photosynthetic photon flux density were higher in the rainy season, while the maximum water potential and vapor pressure deficit in the atmosphere were similar between seasons. The seasonal variations in gas exchange characteristics were influenced by changing weather conditions and were positively correlated with higher air temperatures, rainfall amounts and relative air humidity and negatively correlated with increased insolation. There was no correlation between the maximum leaf water potential and any of the weather variables. Phenylalanine ammonia-lyase activity was similar in the dry and rainy seasons, and higher levels of total phenols and tannins were observed in the dry and rainy seasons, respectively. Phenylalanine ammonia-lyase activity and total phenol contents were negatively influenced by temperature and rainfall in the dry season, and the total tannin contents were mainly correlated with higher temperatures and a lower influence of rainfall in the rainy season. Keywords: gas exchange; Cerrado; phenolic compounds; seasonality. Folhas e cascas do caule de Stryphnodendron adstringens, uma especie do Cerrado brasileiro, foram utilizadas para examinar os padroes sazonais da atividade da fenilalanina amonia-liase e os teores de fenois e taninos totais em 16 individuos adultos, em condicoes de campo. Avaliacoes das trocas gasosas, incluindo fotossintese liquida, transpiracao, condutancia estomatica, densidade de fluxo de fotons fotossinteticamente ativos, temperatura da folha, deficit de pressao de vapor e potencial hidrico foliar foram realizadas. Os resultados foram submetidos a analise de componentes principais. A condutancia estomatica, fotossintese liquida, transpiracao, eficiencia do uso da agua, potencial hidrico minimo e densidade de fluxo de fotons fotossinteticamente ativos foram maiores na estacao chuvosa, enquanto que o potencial hidrico maximo e o deficit de pressao de vapor na atmosfera foram semelhantes entre as estacoes. As variacoes sazonais nas caracteristicas de trocas gasosas foram influenciadas por mudancas nas condicoes climaticas e se correlacionaram positivamente com as maiores temperaturas, precipitacao e umidade relativa do ar e negativamente com o aumento da insolacao. Nao houve correlacao entre o potencial hidrico foliar maximo e as demais variaveis climaticas. A atividade da fenilalanina amonia-liase foi semelhante nas estacoes seca e chuvosa e os maiores teores de fenois e taninos totais foram observados nas estacoes seca e chuvosa, respectivamente. A atividade da fenilalanina amonia-liase e os teores de fenois totais foram influenciados negativamente pela temperatura e precipitacao na estacao seca, e os teores de taninos totais foram correlacionados principalmente com temperaturas mais elevadas, com menor influencia da precipitacao na estacao chuvosa. Palavras-chave: trocas gasosas; Cerrado; compostos fenolicos; sazonalidade.