We analyzed the abnormal shoot in youth (asy) mutant to understand the phase-specific regulation of shoot development. asy showed various shoot abnormalities, including small leaves due to the precocious termination o...We analyzed the abnormal shoot in youth (asy) mutant to understand the phase-specific regulation of shoot development. asy showed various shoot abnormalities, including small leaves due to the precocious termination of cell division, defects in leaf blade-sheath boundary formation, and abnormal shoot apical meristem maintenance at the early vegetative stage. These defects recovered with advanced development. ASY encodes a DUF791 domain protein, which is part of the major facilitator superfamily. Despite stage-specific phenotypes, the ASY expression level was roughly constant throughout development. A paralog of ASY, ASL, exists in the rice genome and is supposed to have redundant functions. ASL expression was relatively low in early-stage embryos but increased at later stages. Thus, asy phenotypes were limited to the stage when ASL expression was suppressed. A homology search revealed that ASY is a homolog of the Chlamydomonas CrMoT2 gene, which encodes a molybdate transporter. ASY was suggested to encode a molybdate transporter based on its sequence similarity with CrMoT2 and predicted transmembrane topology. This is the first report of a CrMOT2-type molybdate transporter in higher plants.展开更多
文摘We analyzed the abnormal shoot in youth (asy) mutant to understand the phase-specific regulation of shoot development. asy showed various shoot abnormalities, including small leaves due to the precocious termination of cell division, defects in leaf blade-sheath boundary formation, and abnormal shoot apical meristem maintenance at the early vegetative stage. These defects recovered with advanced development. ASY encodes a DUF791 domain protein, which is part of the major facilitator superfamily. Despite stage-specific phenotypes, the ASY expression level was roughly constant throughout development. A paralog of ASY, ASL, exists in the rice genome and is supposed to have redundant functions. ASL expression was relatively low in early-stage embryos but increased at later stages. Thus, asy phenotypes were limited to the stage when ASL expression was suppressed. A homology search revealed that ASY is a homolog of the Chlamydomonas CrMoT2 gene, which encodes a molybdate transporter. ASY was suggested to encode a molybdate transporter based on its sequence similarity with CrMoT2 and predicted transmembrane topology. This is the first report of a CrMOT2-type molybdate transporter in higher plants.
