Rice gene, BBH/Lsi1, regulates the color of rice hull by reducing the absorption and deposition of silicon and accumulating excess flavonoid

摘要: The color of grain hull is one the remarkable traits which can be easily identified after heading, especially at mature stage. In present study, a discoloration mutant named black–brown (bbh), was obtained from an indica cultivar Zhenong 34 by mutagenesis with ethyl methane sulfonate (EMS). bbh initially appeared on 15th day and became completely 30th heading. root shorter than that WT during whole growth period. Furthermore, total flavonoids content in hulls silicon deposition leaves were both remarkably higher WT. results map-based cloning indicated trait controlled single recessive nuclear gene, located long arm chromosome 2 physical distance 64.9 kb. comparison gDNA sequence between showed there substitution T to C (+ 2360) third exon LOC_Os02g51110. BBH allelic gene Lsi1, encoded water channel protein (aquaporin) involving uptake. expression levels genes related absorption, transportation distribution detected up- or down-regulated different stages root. Moreover, transcripts structural enzymatic involved flavonoid biosynthesis also had apparent differences mutant. Above all, revealed BBH/Lsi1 responsible reducing absorption accumulating overmuch flavonoid.