Coix lacryma-jobi L. is an Asian plant widely used in traditional medicine. Drought conditions can lead to an impairment of photosynthesis which can be softened by the exogenous application of proline and γ-aminobutyric acid (GABA) to maintain the electron transport chain (ETC) and avoid reactive oxygen species-induced oxidative damage by inducing antioxidative enzymes. The aim of this study was to evaluate the effects of water deficit on C. lacryma-jobi leaves under the application of proline and GABA. Chlorophyll (Chl) a fluorescence emission, antioxidative enzyme activity (catalase, superoxide dismutase, ascorbate peroxidase and guaiacol peroxidase) and proline and GABA contents in leaf tissues were performed in plants subjected to 12 days of drought. Chl a fluorescence indicated impairments on photosynthetic apparatus due to water deficit that resulted into increased activity of antioxidant enzymes. The application of proline but not GABA was more efficient in alleviating the effects of water deficit, as evidenced by the maintenance of the dynamic dissipation of the photosynthetic energy, besides the greater accumulation of proline under these conditions. Water deficit induces alterations in the ETC, which is softened by the application of proline to cope with the deleterious effects of drought in C. lacryma-jobi plant leaves.

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RESUMO A ipeca (Carapichea ipecacuanha) é uma planta medicinal de grande importância financeira devido aos seus princípios ativos presentes em suas raízes, mas há poucos estudos quanto ao seu crescimento e desenvolvimento. Por esse motivo, o presente trabalho tem como objetivo determinar o crescimento em diferentes níveis de sombreamento nas condições ambientais de Niterói-RJ. O período das análises compreendeu a transição das estações de primavera para verão (dezembro de 2014 e janeiro de 2015), envolvendo sombreamentos de 50, 70 e 90% em solo arenoso. Foram avaliados os seguintes parâmetros: altura, diâmetro do colo, número de folhas, área foliar e temperatura do ar e do solo. Quanto aos parâmetros altura e diâmetro, inicialmente, não houve diferença significativa em relação aos sombreamentos, mas no mês de janeiro as plantas no sombreamento de 50% apresentaram maior crescimento da altura em relação aos demais sombreamentos, exibindo um acréscimo de 48% em comparação ao sombreamento de 70%. Quanto área foliar, o sombreamento de 50% também se mostrou mais eficiente, cujas plantas tiveram 80% a mais de crescimento que as plantas do sombreamento de 90%, no mês de dezembro, e cerca de 78% a mais no mês de janeiro. A avaliação de temperatura demonstrou que o isolamento térmico, em todos os três sombreamentos, permitiu uma menor variação de temperatura do solo. Para o crescimento e desenvolvimento das mudas de ipeca o sombreamento de 50%, foi o mais indicado, preferencialmente com isolante térmico, para a diminuição da variação de temperatura, podendo variar com a sazonalidade local. PALAVRAS-CHAVE: Crescimento; planta medicinal; temperatura. LEAF AREA AND HEIGHT OF IPECA ARE ALTERED BY SHADING ABSTRACT The ipeca (Carapichea ipecacuanha) is a medicinal plant with a big financial importance due to its active principle residing in its root, but there is a lack of studies towards its growth and development. For that matter, the present study intends to determinate its growth in different levels of shading on ambient conditions in Niteroi-RJ. The analysis period was between the spring and summer (December 2014 and January 2015) involving shadings of 50, 70 e 90 in sandy soil. The parameters analyzed where: height, diameter, number of leafs, leaf area, soil and atmosphere temperature. In regard of the height and diameter, initially, there were no significant changes between the values acquired in December, however, in January, the plants in the 50% shading showed higher growth compared to the others, growing 48% in comparison to the 70% shading. In the measuring of the leaf area, the 50% shading was also more efficient, the plants had 80% more growth than the 90% shading in December and, around 78% more in January. The measuring of soil temperature was able to determinate that, in all three shadings, the thermal insulation allows less temperature variations. For the growth and development of the ipeca seedlings, the 50% shading was more suitable, especially if provided with thermal insulation, decreasing temperature varia...

Para se obter a melhor qualidade terapêutica e produtividade das plantasmedicinais, o manejo adequado da cultura é fundamental, pois diversosfatores podem interferir. Assim, analisou-se o crescimento das plantas decitronela submetidas a diferentes níveis de cortes na parte aérea e nas raízes.Cinco diferentes proporções de desbaste na raiz (0, 25, 50, 75 e 100%), após145 dias do plantio das mudas e 4 cortes na parte aérea (folhas): sem corte; umcorte aos 145 dias após o plantio (DAP), juntamente com o corte da raiz; um corteaos 228 DAP; e cortes aos 145 e 228 DAP (dois cortes). Foram realizadas quatrocoletas para dados de acúmulo de matéria seca e partição de fotoassimilados.O tratamento com 100% de corte na raiz, mas sem corte nas folhas, aumentouo acúmulo de massa seca em relação aos demais tratamentos, para o últimoperíodo de análise, demonstrando uma recuperação.

This study evaluated the responses of Carapichea ipecacuanha to sunlight stress-induced changes in the electron transport chain and its extended effects on alkaloid production (emetine and cephalin). The treatments consisted of: (i). 50, 70 and 90% shading (controls) and their respective exposure to fullsunlight; besides, full sunlight (55 days of direct sun exposure). Photosynthetic pigments, chlorophyll a fluorescence transient, antioxidant enzymatic system, and quantification of cephalin and emetine were analyzed. Several changes in the Chl a fluorescence induction was observed, such as a decline in the quantum yield of the conversion of photochemical energy and photosynthetic performance; increase in emetine production of plants exposed to full sunlight. These results demonstrated that ipecac plants are extremely sensitive to full exposure to solar radiation, especially in periods with high temperatures, such as in summer, however with increment in emetine production.