Gabriel Baiaca Felix de Siqueira¹, Lucas Carvalho de Freitas ¹, Tercilio Calsa Junior ¹

Sugarcane (Saccharum spp.) is a crop plant of species of the Poaceae family with great relevance in social, environmental and economic terms, and is the main feedstock to produce sugar and bioethanol biofuels. Its development and yield are severely affected by stressing environmental factors, as excessive incidence of UVB radiation and water deficit. Previous analysis on differential cell wall proteome of sugarcane commercial hybrids, under UVB radiation stress and water deficit, demonstrated that these two combined stresses caused the accumulation of glyoxalase 1 (GLO1), an enzyme present in the cell wall and important for detoxification against oxidative stress and cytotoxicity caused by excess methylglyoxal (MG), a reactive byproduct of glucose metabolism capable to damage proteins, lipids and nucleic acids. This work aimed at the in silico characterization of GLO1. BLASTP was performed for the GLO1 protein, UniProt accession W0F9T0, with unrestricted taxonomy, considering an identity rate ≥ 90 % and e-value 0.0. The most similar sequences were mapped using the Uniprot Multalin tool. From the obtained data through sequence alignments via BLASTP/NCBI, it was possible to construct a phylogenetic tree. Additionally, a protein interaction network was generated using the STRING tool. In the analyses performed within the Viridiplantae taxon, 34 proteins with high similarity to GLO1 from Saccharum were identified. The phylogenetic tree revealed that this protein is highly conserved among several grass species, such as rush (Juncus spp.), Setaria italica, millet (Panicum miliaceum) and brachiaria (Urochloa spp.), suggesting a relevant functional role in Poaceae metabolism. The interaction network showed GLO1 as regulador of cellular ROS balance, confirming its central role in response to methylglyoxal oxidative stress, linked to other UVB stress related proteins whose action involve protection against UVB damage and antioxidant responses.   The CD-Search results revealed that the VOC Superfamily domain is conserved in all analyzed species with similar GLO1, suggesting its functional and evolutionary conservation in GLO1 coding gene(s) in the grass group. These results indicate possible applications in sugarcane breeding programs for GLO1 as selection biomarker, especially for abiotic and/or oxidative stress tolerance.

Agradecimentos: Agradeço aos membro do Laboratório de Genômica e Proteômica de Plantas (LGPP) da Universidade Federal de Pernambuco, fundamentais para realização deste trabalho, da graduação e pós-graduação, especialmente meu orientador Prof. Dr. Tercilio Calsa Junior e o Dr. Lucas Carvalho.