Differential expression of two genes for sucrose-phosphate synthase in sugarcane: molecular cloning of the cDNAs and comparative analysis of gene expression.

Two cDNA clones, pSoSPS1 and pSoSPS2, encoding sucrose-phosphate synthase (SPS) of sugarcane were isolated from a leaf cDNA library. Northern analysis revealed the transcript of SoSPS1 to be predominant in leaves, but that of SoSPS2 to be distributed not only in leaves but also in roots at a similar level. The transcript of SoSPS1 was markedly accumulated during greening of etiolated leaves, whereas that of SoSPS2 was constitutively expressed. These findings indicate that SPS in sugarcane is encoded by multiple genes, which show organ-specificity and are differentially regulated in response to light.