missense mutation in the transmembrane domain of CESA4 affects protein abundance in the plasma membrane and results in abnormal cell wall biosynthesis in rice

• Published in: Plant molecular biology Vol. 71; no. 4-5; pp. 509 - 524
• Main Authors: Zhang, Baocai, Deng, Lingwei, Qian, Qian, Xiong, Guangyan, Zeng, Dali, Li, Rui, Guo, Longbiao, Li, Jiayang, Zhou, Yihua
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.11.2009; Springer Netherlands; Springer Nature B.V
• Subjects: Amino Acid Sequence; Biochemistry; Biomechanical Phenomena; Biomedical and Life Sciences; Biosynthesis; Cell Membrane - metabolism; Cell Wall - genetics; Cell Wall - metabolism; Cellular biology; Cellulose; Cloning; Gene Expression Regulation, Plant - genetics; Gene Expression Regulation, Plant - physiology; Genotype & phenotype; Life Sciences; Membrane Proteins - chemistry; Membrane Proteins - genetics; Membrane Proteins - metabolism; Membrane Proteins - physiology; Microscopy, Confocal; Microscopy, Electron, Transmission; Molecular biology; Molecular Sequence Data; Mutation; Mutation, Missense; Oryza - genetics; Oryza - growth & development; Oryza - metabolism; Oryza - ultrastructure; Oryza sativa; Phylogeny; Plant biology; Plant Pathology; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Plants, Genetically Modified - genetics; Plants, Genetically Modified - growth & development; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - ultrastructure; Protein Structure, Tertiary; Rice; Sequence Homology, Amino Acid; Cellulose synthase; Missense mutation; Mechanical strength; Cellulose; Rice
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/s11103-009-9536-4

Cellulose synthase (CESA) is a critical catalytic subunit of the cellulose synthase complex responsible for glucan chain elongation. Our knowledge about how CESA functions is still very limited. Here, we report the functional characterization of a rice mutant, brittle culm11, that shows growth retardation and dramatically reduced plant strength. Map-based cloning revealed that all the mutant phenotypes result from a missense mutation in OsCESA4 (G858R), a highly conserved residue at the end of the fifth transmembrane domain. The aberrant secondary cell wall of the mutant plants is attributed to significantly reduced cellulose content, abnormal secondary wall structure of sclerenchyma cells, and overall altered wall composition, as detected by chemical analyses and immunochemical staining. Importantly, we have found that this point mutation decreases the abundance of OsCESA4 in the plasma membrane, probably due to a defect in the process of CESA complex secretion. The data from our biochemical, genetic, and pharmacological analyses indicate that this residue is critical for maintaining the normal level of CESA proteins in the plasma membrane.