Abstract
We previously demonstrated that OsBOR3 is an efflux transporter of B, necessary for normal growth in rice plants under B-limiting condition. In the present study, we determined B concentration in plants carrying Tos17 in the OsBOR3 gene. B concentration in roots and leaves was not different between the mutant and wild type plants both under the normal and B-limiting conditions. However, considering the difference in the growth, total B taken-up and transported were lower in the mutant plants than the wild type plants. Several independent lines of transgenic plants carrying Promoter:GUS fusion gene were generated and patterns of GUS activities were observed. In root tips, GUS proteins were found in exodermis, while in the elongation zones, it was found both in endodermis. These data suggested that localization of OsBOR3 changes depending on growth stages of roots and the physiological functions may also be changed in the course of root development.
