Anatomical and ultrastructural studies reveal temporal and spatial variation in the oil production in leaves of the diesel tree (Copaifera langsdorffii, Leguminosae)

Made available in DSpace on 2020-12-12T02:43:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The oily resin produced by Copaifera langsdorffii, commonly called oil of copaiba, is widely exploited by the drug, cosmetic, and biodiesel industries. The distribution of oily secretory cavities and canals (secretory spaces) over the vegetative body characterizes this species. Oil is stored inside the lumen of the secretory spaces and only reaches the organ surface after injuries. Nonetheless, translucent oily deposits occur on the adaxial surface of intact young leaves. In this study, we searched for further sources of oil production in C. langsdorffii leaves in addition to the well-known secretory cavities and investigated the mechanisms of secretion. Leaves in different developmental stages were collected from adult plants and processed for studies on light and transmission electron microscopies. The primary finding of this study was the involvement of the chlorenchyma cells in lipid biosynthesis, in addition to the secretory cavities. The secretory activity of cavities and chlorenchyma cells overlapped in young leaves. Ultrastructurally, secretory cavity cells exhibited abundant smooth endoplasmic reticulum profiles and oleoplasts, whereas the chlorenchyma cells had large chloroplasts with oil inclusions. Our data suggest that the oily material on the leaf surface arose from the chlorenchyma and was transported via the apoplast. These findings open new avenues for understanding oil biosynthesis regulation in mesophyll cells and planning of future strategies for the biotechnological application of C. langsdorffii leaves. Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Goiás State University (UEG) Department of Botany Institute of Biosciences São Paulo State University (UNESP) Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Department of Botany Institute of Biosciences São Paulo State University (UNESP) CAPES: 001 CNPq: 02657/2011-8 FAPESP: 2008/55434-7 CNPq: 303981/2018-0