JM García1, C Molina2, V Di Pauli1, PD Fontana1, L Martínez Calsina1, LE Erazzú1 and A Acevedo2
1EEA Famaillá INTA, Ruta Provincial Nº 301, km 32, 4132, Tucumán, Argentina; garcia.josemaria@inta.gob.ar
2Instituto de Suelos, CIRN-INTA, 1712 Castelar, Buenos Aires, Argentina
Lignin is a complex polymer that reduces biomass recalcitrance and limits the use of sugarcane (Saccharum hybrids) for second-generation ethanol production. Among the key genes involved in lignin biosynthesis pathway, caffeic acid O-methyltransferase (COMT) impacts on both lignin content and composition. Therefore, understanding the genetic variability of COMT is crucial for developing molecular markers to assist sugarcane breeding programs in the selection of genotypes with improved biomass digestibility. This study aims to sequence the COMT gene in selected sugarcane genotypes to identify single nucleotide polymorphisms (SNPs). Nine Saccharum genotypes were used, including commercial cultivars, energy-cane, clones with contrasting lignin content, and one S. spontaneum accession. DNA was extracted, and specific primers for COMT gene were designed using cultivar R570 genome as a reference. A 1103 bp sequence was amplified via PCR and sequenced using the Sanger method. The analysis revealed a 100% alignment among the sequences, reflecting close genetic relationship between USA and Argentina germplasm. Three to nine SNPs were identified in coding regions when compared to reference genomes that could affect COMT functionality and lignin content. Future studies should explore additional COMT gene regions and investigate gene expression to better understand lignin variability in sugarcane.