The dbs1 mutant used in this study was identified in a mutant
library of Oryza sativa L., which was generated using N-methyl-Nnitrosourea.
WT and dbs1 plants were grown in a greenhouse at 30°C
(day) and 24°C (night), or were germinated and grown on MS medium
(Murashige and Skoog 1962) under fluorescent lighting at 30°C.