A transcriptomic approach reveals novel roles of nitric oxide in sunflower roots

DE LA CANAL L

Mar del Plata

Conferencia; Symposium Functional Genomics for Gene Regulation, VIII Encuentro Latinoamericano y del Caribe de Biotecnología, Redbio 2013; 2013

Redbio Argentina

Despite the importance of nitric oxide (NO) as a root growth regulator, the knowledge about the genes and metabolic pathways modulated by NO in this process is still limited. We have analysed the role of NO in root architecture and gene expression through the depletion of endogenous NO using the scavenger cPTIO. The transcriptional changes have been analysed using a large-scale approach. A microarray analysis showed 330 genes regulated in the roots (p≤0.001) upon endogenous NO depletion. A general cPTIO-induced up-regulation of genes involved in the lignin biosynthetic pathway was observed. Even if no detectable changes in total lignin content could be detected, cell walls analyses revealed that the ratio G/S lignin increased in roots treated with cPTIO. This means that endogenous NO may control lignin composition in planta. Our results suggest that a fine tuning regulation of NO levels could be used by plants to regulate root architecture and lignin composition. The functional implications of these findings are discussed.