Light spectrum quality is an important signal for plant growth and development. We aimed to analyze the effects of different light spectra on in vitro shoot development and proteomic and polyamine (PA) profiles in shoots of Cedrela fissilis. Cotyledonary and apical nodal segments were grown under different light emitting diode (LED) lamps and a fluorescent lamp. Shoots from cotyledonary nodal segments cultured with 6-benzyladenine (BA) grown under WmBdR LED increased their length, fresh and dry matter compared to shoots grown under fluorescent light. A non-redundant protein databank generated by transcriptome sequencing and de novo assembly of C. fissilis improved, and almost doubled, protein identification compared to a Citrus sinensis databank. Using the C. fissilis protein databank, a total of 616 proteins were identified, with 23 up- and 103 downaccumulated in shoots under WmBdR LED compared to fluorescent lamp. Differential accumulation of argininosuccinate synthase protein was associated with an increase in free-Put contents and, consequently, with higher shoot elongation under WmBdR LED. Furthermore, the proteins S-adenosylmethionine synthase, which is related to PA and ethylene biosynthesis, and 1-aminocyclopropane-1-carboxylate oxidase, related to ethylene biosynthesis, were unique in shoots grown under fluorescent lamp, showing lower elongation of shoots, possibly due to ethylene production. The downaccumulation of calreticulin, heat shock proteins, plastid-lipid-associated protein, ubiquitin-conjugating enzymes, and ultraviolet-B receptor UVR8 isoform X1 could be related to better shoot length under LED. This work provides important data related to the effects of light spectrum quality on in vitro morphogenesis via modulation of specific proteins and free-Put biosynthesis.