Abstract
Polysaccharide-linked hydroxycinnamoyl esters (PHEs) are accumulated in cell walls of cortical fibers and vascular cells in rice. PHEs are thought to be very important cell wall components, which strengthen the cell wall and prevent pathogen attack. We found that a rice dwarf mutant Fukei71 (d50) abnormally accumulated PHEs in cell walls of irregular shaped-internode parenchyma cells. The genetic approach revealed that D50 gene encodes an inositol polyphosphate 5-phosphatase (IP5P). Expression pattern of D50 gene was examined by RT-PCR and promoter analysis. RT-PCR showed that D50 is expressed in roots, leaf blades, leaf sheaths, stems, and flowers at almost the same levels. Promoter-GUS analysis confirmed the expression of D50 mainly in meristematic tissues of young internodes. Currently we are determining the intracellular localization of the D50 protein by particle bombardment with CaMV35S::D50::YFP construct.
