Abstract
It has been uncovered that the His-Asp phosphorelay plays an important role in the signal transduction of plants in response to the stimulus such as phytohormones and osmotic stress. Eukaryotic type of His-Asp phosphorelay is composed of three types of factors; sensor His-kinase, His-containing-phosphotransmitter and response regulator (RR). The type-B family of RRs has been shown to function as transcriptional factor. To date, the details of the signaling pathways mediated by type A-family of RRs remain to be elucidated. In maize, the cDNAs encoding for the type-A family of RRs (ZmRR1,2,4,5,6,7) and type-B family of RRs (ZmRR8,9,10) were isolated and the expression patterns of these genes are analyzed. We performed yeast two-hybrid screen to isolate the interacting proteins with ZmRR1. One of the interacting proteins, ZmHD1, contained HD domain that might function as metal-dependent phosphohydrolase. The biochemical characterization on ZmHD1 will be presented.
