Substâncias antifúngicas constitutivas e induzidas em folhas e suspensões celulares de Rudgea jasminoides (Cham.) Müll. Arg. (Rubiaceae)

Abstract

-(Constitutive and induced antifungal compounds in leaves and cell suspension cultures of Rudgea jasminoides (Cham.) Müll. Arg. (Rubiaceae)). Rudgea jasminoides (Cham.) Müll. Arg. is a woody Rubiaceae species from tropical forest that synthesized antifungal secondary metabolites when challenged by fungi. Members of the Rubiaceae are among the few plants that are easily taken into cell cultures to produce substantial amounts of secondary products that surpass those of the whole plant. In this work we analyzed the presence of constitutive and induced antifungal compounds produced by leaves and cell suspension cultures of this species. Oligogalacturonides (OGAs), salicylic acid (AS), nitric oxide (NO), and yeast β-glucan fragments were used as elicitors. Constitutive compounds with antifungal activity were detected in cell suspension cultures of R. jasminoides, mainly during the stationary growth phase. They were found in higher diversity and amounts than those present in leaves. Treatment with β-glucan fragments increased the production of constitutive compounds and induced the synthesis of antifungal metabolites absent in non-elicited cultures (phytoalexins), mainly during the exponential growth phase. OGAs derived from R. jasminoides leaf cell walls showed similar effect. Under our experimental conditions, the endogenous signaling molecules salicylic acid and nitric oxide were toxic to the cells and did not act as elicitors of antifungal compounds in suspension cultures of R. jasminoides. Our data indicate that cell suspension cultures of R. jasminoides are able to synthesize antifungal compounds and their production can be enhanced by fungal or plant elicitors.Key words -antifungal compounds, cell suspension, elicitors, phytoalexin, Rubiaceae RESUMO -(Substâncias antifúngicas constitutivas e induzidas em folhas e suspensões celulares de Rudgea jasminoides (Cham.) Müll. Arg. (Rubiaceae)). Rudgea jasminoides (Cham.) Müll. Arg. é uma rubiácea arbórea nativa da fl oresta tropical que sintetiza metabólitos secundários antifúngicos, quando em contato com fungos. Membros da família Rubiaceae estão entre as poucas plantas facilmente mantidas em cultura de tecidos e que produzem quantidades substanciais de metabólitos secundários que ultrapassam os níveis normalmente encontrados na planta intacta. Neste trabalho foi analisada a presença de compostos antifúngicos constitutivos e induzidos produzidos por folhas e suspensões celulares dessa espécie. Oligogalacturonídeos (OGAs), ácido salicílico(AS), óxido nítrico(NO) e fragmentos de β-glucano de leveduras foram usados como eliciadores. Substâncias constitutivas com atividade antifúngica foram detectadas nas suspensões celulares de R. jasminoides, principalmente na fase estacionária do crescimento das culturas. Essas substâncias foram encontradas em maior diversidade e quantidade quando comparadas às das folhas. O tratamento com fragmentos de β-glucano de leveduras aumentou a produção de substâncias antifúngicas constitutivas e induziu a síntese de compostos antifú...

Histochemical Screening of Leaves Compared to in situ and in vitro Calluses of Solanum aculeatissimum Jacq.

“…Victório (2015) emphasizes that light has the capacity to influence the entire secondary metabolism and plant growth. Abiotic elicitors, such as the absence or presence of light, have been used for induction of biosynthesis pathways (Oliveira et al, 2009) and for accumulation and distribution of organic compounds.…”

“…Therefore, the use of biotechnology in the cultivation of plant cells can be an alternative for increasing the output of bioactive compounds through the study of plant biosynthetic pathways, which in turn can support studies in gathering relevant data for improving phytochemical production. Oliveira et al (2009) emphasized the cultivation of cells and plant tissues as a research alternative in the production of several secondary metabolites in seedlings and calluses. Yendo et al (2010) and Karuppusamy (2009) assert that some strategies have been used for improving the production of metabolites in cultures based on the principle of increasing the yield of the metabolite of interest.…”

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

“…Since then, suspension-cultured cells of R. jasminoides have been used as a model system to study the biological activity of cell wall fragments (Oliveira Júnior et al 2006), to evaluate the production of constitutive fungitoxic compounds and anthraquinones (Oliveira et al , 2009 and to understand the differential uptake of sugars by cells of a tree Rubiaceae species (Kretzschmar et al 2007). The homogeneous culture of R. jasminoides consists of predominantly undifferentiated cells with mainly primary cell walls (Stella and Braga 2002).…”