Molecular characterization of two genes, ZmRPS4 and ZmMET1, expressed in the tiller bases in maize

The initiation and outgrowth of tillers is one of the many important traits of most monocotyledonous plants. The influence of corn tiller on grain yields, which is probably related to the degree of introgression of teosinte, remains controversial, but it is a useful trait for increasing total biological yields. In order to study the molecular events occurring during the formation of tiller, two clones of ZmRPS4 (Zea mays ribosomal protein S4) and ZmMET1 (Zea mays multi- ears and tillers1) were isolated from the tiller bases in maize by differential hybridization. The ZmRPS4 and ZmMET1 genes were more highly expressed in tissues, e.g., tiller bases and brace roots, than in leaf tissues. The ZmRPS4 gene was expressed in the vascular tissues of tiller bases and brace roots. The ZmMET1 gene was expressed in the vascular tissues of tiller bases and brace roots, and in leaf primordial of tiller bases. In terms of plant hormone treatments, the ZmRPS4 gene was induced by ABA, GA, and kinetin, but the ZmMET1 gene only responded to kinetin. The two genes are discussed in relation to the formation of tillers in maize.