Indução, caracterização bioquímica e ultra-estrutural de calos de aroeira-do-sertão (Myracrodruon urundeuva Fr. All.)

Abstract

RESUMO:A aroeira-do-sertão (Myracrodruon urundeuva Fr. All.) é espécie arbórea que apresenta grande valor econômico devido às propriedades químicas da casca com elevado teor de taninos. Em decorrência da exploração predatória encontra-se inserida na lista oficial de espécies da flora brasileira ameaçadas de extinção na categoria vulnerável. A micropropagação vem sendo colocada como importante forma de multiplicação dessa espécie, na busca de alternativa para a exploração sustentável. Este trabalho foi realizado com o objetivo de induzir calos a partir de segmentos foliares usando 2,4-D e caracterizá-los quanto aos aspectos morfológicos e bioquímicos. Os resultados obtidos indicam que é possível induzir calos a partir de segmentos foliares de aroeirado-sertão utilizando-se 2,4-diclorofenoxiacético (2,4-D). Os calos obtidos foram compactos e não-embriogênicos, apresentando valores médios de 43,32 mg g -1 de açúcares solúveis totais; 23,62 mg g -1 de açúcares redutores; 3,157 mg g -1 de proteína total; 3,147 mg g -1 de aminoácidos livres e 0,914 mg g -1 de compostos fenólicos totais na matéria fresca. Palavras-chave: aroeira, calogênese, MEV, análises bioquímicasABSTRACT: Induction, biochemical and ultrastructural characterization of the callus of "aroeira-do-sertão" (Myracrodruon urundeuva Fr. All.). "Aroeira-do-sertão" (Myracrodruon urundeuva Fr. All.) is a tree species that has great economic value due to the chemical properties of its bark, which has high tannin content. On account of the predatory exploitation it has been placed in the official list of threatened species of the Brazilian flora, in the vulnerable category. Micropropagation has been considered an important form of multiplication of this species in the search for an alternative for its sustainable exploitation. This study was conducted with the aim of inducing callus from leaf segments using 2,4-D and characterizing them according to their morphological and biochemical aspects. The obtained results indicate that it is possible to induce callus from leaf segments of M. urundeuva using 2,4-dichlorophenoxyacetic (2,4-D). The obtained calluses were compact and non-embryogenic, with average values of 43.32 mg g -1 total soluble sugars, 23.62 mg g -1 reducing sugars, 3.157 mg g -1 total protein, 3.147 mg g -1 free-form amino acids and 0.914 mg g -1 phenolic compounds in the fresh matter.

Indirect in vitro organogenesis of Hancornia speciosa Gomes

“…has also showed the highest percentage of callus formation (98%) with further shooting regeneration in the culture medium supplied with 6.0 µM 2,4-D and 0.5 µM TDZ (BASKARAN et al, 2009) which demonstrates that the presence of 2,4-D was crucial to obtain the result. The superiority of this synthetic auxin in comparison to other auxin and cytokinin sources during indirect organogenesis has also been recorded in essays with Lavandula angustifolia buds in which the use of 4.52 µM 2,4-D and 1.44 µM GA 3 in the culture medium was the most suitable combination to induce calluses (BONA et al, 2012), as well as for leaf segments of Myracrodruon urundeuva in which the use of 4.52 µM 2,4-D promoted the highest rate of callus formation (VASCONCELOS et al, 2012). The importance of the auxins as an inductor of the cell competence is known and the 2,4-D has been particularly reported in literature as a necessary regulator for the somatic cell dedifferentiation (RAGHAVAN, 2004;PINTO et al, 2010;LI et al, 2012) most of all from parenchyma cells of vascular bundles (LI et al, 2012).…”

Induction and growth curve of calli from leaf and nodal explants of genipap

“…The growth curve was established by determining the fresh weight of calli from the day of inoculation (time 0) at 10-day intervals up to 60 days, which correspond to first cultivation period, considering the auxin available in the culture medium (SACHS, 1991). The percentage of calli growth was determined from the equation (VASCONCELOS et al, 2012):…”

“…The knowledge about calli growth dynamic, together with in vitro culture, may support the establishment of optimized protocols, suggesting the most suitable moment for transferring the material to a fresh medium (VASCONCELOS et al, 2012). Four different stages were verified through the growth curve: lag, exponential, stationary and decline (GEORGE, 2008).…”

“…The ability of plants to produce and accumulate secondary metabolites has been decisive to develop technologies based on the in vitro culture of cells, tissues and organs (OKSMAN-CALDENTEY;INZÉ, 2004). Undifferentiated cells, or calli, have been used in studies focused on the production of bioactive compounds, but could also be a useful model to study the first steps towards their regulation and biosynthesis (VASCONCELOS et al, 2012).…”

POTENCIAL ALELOPÁTICO DE ESPÉCIES ARBÓREAS DA CAATINGA SOBRE A EMERGÊNCIA E O DESENVOLVIMENTO INICIAL DE Allium fistulosum L.

“…A entrecasca e as folhas desta espécie são indicadas para o tratamento de lesões e úlceras de pele e mucosas e de doenças no trato urinário (LORENZI, 2008;VASCONCELOS et al, 2012), ademais, a aroeira-do-sertão possui princípios alergênicos e não deve ser cultivada em locais de fácil acesso ao público (NUNES et al, 2008).…”