Os09g02650

The rice Brittle Culm 12(BC12) gene encodes a dual-targeting kinesin-4 protein, controls cell-cycle progression and wall properties in rice.

Function

This gene encodes a kinesin-4 protein, which is participated in cell-cycle progression, cellulose microfibril deposition and cell wall composition in the monocot plant rice. bc12 mutants display dwarfism resulting from a significant reduction in cell number and brittleness due to an alteration in cellulose microfibril orientation and wall composition. Similar to the typical kinesin-4 in animals,BC12 has an nuclear locational signal (NLS) and functions in mitosis. BC12 is present in both the nucleus and cytoplasm and associated with microtubule arrays during cell division. BC12 interacts with CDKA;3 (cyclin-dependent kinase) and probably undergoing phosphorylation for the purpose of regulation. BC12 is essential to exert multiple roles in cell division and cell wall biogenesis in rice.

Mutation

bc12: A 26bp deletion in the 4th exon of one open reading frame (ORF), results in a frameshift. which is related with the dwarfism and brittleness phenotype.

Expression pattern

BC12 is universally expressed in all organs. with higher expression in panicles and culms. RNA in situ hybridization reveals that BC12 is expressed in young tissues, includeing the initiating adventitious roots, primary root tips, flower primordia and intercalary meristems, all tissues in which cells are undergoing vigorous cell division.

Knowledge extension

FRA1 is the homolog gene of BC12 in Arabidopsis. FRA1 which is found in the cytoplasm,was the first functionally identified kinesin-4 member in plants. The fra1 mutant exhibits reduced plant height and fragile fibers as a result of aberrant deposition of cellulose microfibrils in the cell wall.