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BRITTLE PLANT1 is required for normal cell wall composition and mechanical strength in rice
Author(s) -
Zhang Yuanyan,
Wang Yihua,
Wang Chunming,
Rautengarten Carsten,
Duan Erchao,
Zhu Jianping,
Zhu Xiaopin,
Lei Jie,
Peng Chao,
Wang Yunlong,
Teng Xuan,
Tian Yunlu,
Liu Xi,
Heazlewood Joshua L.,
Wu Aimin,
Wan Jianmin
Publication year - 2021
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.13050
Subject(s) - biochemistry , cell wall , sugar , mutant , chemistry , nucleotide sugar , monosaccharide , cellulose , galactose , biosynthesis , enzyme , gene
A series of nucleotide sugar interconversion enzymes (NSEs) generate the activated sugar donors required for biosynthesis of cell wall matrix polysaccharides and glycoproteins. UDP‐glucose 4‐epimerases (UGEs) are NSEs that function in the interconversion of UDP‐glucose (UDP‐Glc) and UDP‐galactose (UDP‐Gal). The roles of UDP‐glucose 4‐epimerases in monocots remain unclear due to redundancy in the pathways. Here, we report a brittle plant ( bp1 ) rice mutant that exhibits brittle leaves and culms at all growth stages. The mutant culms had reduced levels of rhamnogalacturonan I, homogalacturonan, and arabinogalactan proteins. Moreover, the mutant had altered contents of uronic acids, neutral noncellulosic monosaccharides, and cellulose. Map‐based cloning demonstrated that OsBP1 encodes a UDP‐glucose 4‐epimerase (OsUGE2), a cytosolic protein. We also show that BP1 can form homo‐ and hetero‐protein complexes with other UGE family members and with UDP‐galactose transporters 2 (OsUGT2) and 3 (OsUGT3), which may facilitate the channeling of Gal to polysaccharides and proteoglycans. Our results demonstrate that BP1 participates in regulating the sugar composition and structure of rice cell walls.