Brittle culm 25, which encodes an UDP-xylose synthase, affects cell wall properties in rice
Siliang Xu,
Mengchen Zhang,
Junhua Ye,
Dongxiu Hu,
Yuanyuan Zhang,
Zhen Li,
Junrong Liu,
Yanfei Sun,
Shan Wang,
Xiaoping Yuan,
Yue Feng,
Qun Xu,
Xinghua Wei,
Dali Zeng,
Yaolong Yang
Affiliations
Siliang Xu
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Mengchen Zhang
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Junhua Ye
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Dongxiu Hu
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Yuanyuan Zhang
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Zhen Li
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Junrong Liu
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Yanfei Sun
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Shan Wang
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Xiaoping Yuan
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Yue Feng
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Qun Xu
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China
Xinghua Wei
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China; Corresponding authors.
Dali Zeng
The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, Zhejiang A & F University, Hangzhou 311300, Zhejiang, China; Corresponding authors.
Yaolong Yang
China National Center for Rice Improvement/State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China; Corresponding authors.
Because plant mechanical strength influences plant growth and development, the regulatory mechanisms underlying cell-wall synthesis deserve investigation. Rice mutants are useful for such research. We have identified a novel brittle culm 25 (bc25) mutant with reduced growth and partial sterility. BC25 encodes an UDP-glucuronic acid decarboxylase involved in cellulose synthesis and belongs to the UXS family. A single-nucleotide mutation in BC25 accounts for its altered cell morphology and cell-wall composition. Transmission electron microscopy analysis showed that the thickness of the secondary cell wall was reduced in bc25. Monosaccharide analysis revealed significant increases in content of rhamnose and arabinose but not of other monosaccharides, indicating that BC25 was involved in xylose synthesis with some level of functional redundancy. Enzymatic assays suggested that BC25 functions with high activity to interconvert UDP-glucuronic acid (UDP-GlcA) and UDP-xylose. GUS staining showed that BC25 was ubiquitously expressed with higher expression in culm, root and sheath, in agreement with that shown by quantitative real-time (qRT)-PCR. RNA-seq further suggested that BC25 is involved in sugar metabolism. We conclude that BC25 strongly influences rice cell wall formation.
