TITLE:
ABNORMAL SHOOT IN YOUTH, a Homolog of Molybdate Transporter Gene, Regulates Early Shoot Development in Rice
AUTHORS:
Ken-Ichiro Hibara, Wataru Hosoki, Tsuneo Hakoyama, Yoshihiro Ohmori, Toru Fujiwara, Jun-Ichi Itoh, Yasuo Nagato
KEYWORDS:
ABNORMAL SHOOT IN YOUTH; Early Vegetative Stage; Shoot Meristem; Rice; Molybdenum; Transporter
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.5A,
May
30,
2013
ABSTRACT: 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.