LAUSR

Cattleya tigrina is an endangered Brazilian native orchid with ornamental potential. Biotechnological tools based on tissue culture techniques are effective for its mass propagation and conservation. Protocorm-like bodies (PLBs) were induced from leaves in culture medium supplemented with plant growth regulators, and generated complete in vitro plants. To deepen on the mechanism underlying this morphogenetic route, this study is aimed to identify and characterize differentially expressed proteins during C. tigrina PLBs development. Leaves were inoculated in in culture medium Murashige and Skoog (MS) supplemented with 9 μM Thidiazuron, and PLBs t were collected after 30, 60 and 100 days in culture. Proteomic analysis performed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry detected 122, 132 and 447 protein after 30, 60 and 100 days, respectively. During PLBs development, 36 proteins were differentially expressed. Proteins related to energy and carbohydrate metabolism, cell proliferation, protein processing, and secondary metabolism and phytohormones were assessed showing their relevance in the process of development of PLBs. Many proteins related to metabolic and energy processes were identified after 60 and 100 days in culture, suggesting their role in which is cell division and differentiation. Enolase was only present after 100 days in culture, thus being a candidate as a molecular marker in this developmental phase.