Abstract
Leaf cells undergo two main developmental events; i.e., cell proliferation and cell differentiation,
before maturation. These events occur sequentially at specific positions and with specific timing
during leaf development. To understand the transition from cell proliferation to cell differentiation
of rice leaves, we analyzed rice leaves from both morphological and molecular viewpoints.
The results of anatomical, morphological, and histochemical analyses indicated that P4 leaf primordium
is the stage when dynamic transition of the cellular state from immature to mature
along the proximal-distal axis of the leaf occurs. We screened for marker genes showing a dynamic
expression pattern along the proximal-distal axis of the P4 leaf, and applied them to expression
analysis in wild-type and various morphogenetic mutants. The changes in expression pattern of
the marker genes varied between developmental stages and between mutants. Our analysis reinforced
previous data regarding the developmental transition of wild-type rice leaves and indicated
that the transition can be monitored using our molecular markers. The results of this study
indicate that expression analysis using these molecular markers would be valuable for understanding
the genetic effects on leaf development in various leaf morphogenetic mutants.