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A Missense Mutation in the Zinc Finger Domain of OsCESA7 Deleteriously Affects Cellulose Biosynthesis and Plant Growth in Rice.

Wang D, Qin Y, Fang J, Yuan S, Peng L, Zhao J, Li X - PLoS ONE (2016)

Bottom Line: The brittle culms resulted from reduced mechanical strength due to a defect in thickening of the sclerenchyma cell wall and reduced cellulose content in the culms of the S1-24 mutant.The OsCESA7 gene is expressed predominantly in the culm at the mature stage, particularly in mechanical tissues such as vascular bundles and sclerenchyma cells, consistent with the brittle phenotype in the culm.These results indicate that OsCESA7 plays an important role in cellulose biosynthesis and plant growth.

View Article: PubMed Central - PubMed

Affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.

ABSTRACT
Rice is a model plant species for the study of cellulose biosynthesis. We isolated a mutant, S1-24, from ethyl methanesulfonate (EMS)-treated plants of the japonica rice cultivar, Nipponbare. The mutant exhibited brittle culms and other pleiotropic phenotypes such as dwarfism and partial sterility. The brittle culms resulted from reduced mechanical strength due to a defect in thickening of the sclerenchyma cell wall and reduced cellulose content in the culms of the S1-24 mutant. Map-based gene cloning and a complementation assay showed that phenotypes of the S1-24 mutant were caused by a recessive point mutation in the OsCESA7 gene, which encodes cellulose synthase A subunit 7. The missense mutation changed the highly conserved C40 to Y in the zinc finger domain. The OsCESA7 gene is expressed predominantly in the culm at the mature stage, particularly in mechanical tissues such as vascular bundles and sclerenchyma cells, consistent with the brittle phenotype in the culm. These results indicate that OsCESA7 plays an important role in cellulose biosynthesis and plant growth.

No MeSH data available.


Related in: MedlinePlus

The site of the mutation in the S1-24 mutant and phylogenetic analysis of OsCESA7.(A) Multiple alignments of the N-terminal region of 11 members of the OsCESA family and 8 members of the AtCESA family. The mutated residue (cysteine 40) is highly conserved. (B) Phylogenetic analysis of CESAs. The scale bar is an indicator of genetic distance based on branch length.
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pone.0153993.g009: The site of the mutation in the S1-24 mutant and phylogenetic analysis of OsCESA7.(A) Multiple alignments of the N-terminal region of 11 members of the OsCESA family and 8 members of the AtCESA family. The mutated residue (cysteine 40) is highly conserved. (B) Phylogenetic analysis of CESAs. The scale bar is an indicator of genetic distance based on branch length.

Mentions: Multiple alignments revealed that the mutation site (cysteine) at amino acid position 40 of OsCESA7 in the S1-24 mutant is highly conserved in 19 of 21 members of the OsCESA and AtCESA gene families (Fig 9A, S3 Table). This strong conservation indicates that this residue in the OsCESA zinc finger domain is important and necessary. We analyzed the evolutionary relationships among the CESA families in rice and Arabidopsis. As shown in Fig 9B, CESA members clustered into several clades. OsCESA4, OsCESA7, and OsCESA9, for which mutants have been identified and characterized [14–17], belonged to a monophyletic clade and was most closely related to AtCESA8, AtCESA4, and AtCESA7, respectively, while other CESAs were distributed in clades of three or four members. These results indicate that functions of some CESA members are redundant and that others are distinctive. Cellulose synthesis requires the cooperation of at least two to three different CESA gene family members [4, 6]. Diverse CESA genes would enable the formation of multiple subunit complexes essential for cellulose synthesis in cell wall biosynthesis.


A Missense Mutation in the Zinc Finger Domain of OsCESA7 Deleteriously Affects Cellulose Biosynthesis and Plant Growth in Rice.

Wang D, Qin Y, Fang J, Yuan S, Peng L, Zhao J, Li X - PLoS ONE (2016)

The site of the mutation in the S1-24 mutant and phylogenetic analysis of OsCESA7.(A) Multiple alignments of the N-terminal region of 11 members of the OsCESA family and 8 members of the AtCESA family. The mutated residue (cysteine 40) is highly conserved. (B) Phylogenetic analysis of CESAs. The scale bar is an indicator of genetic distance based on branch length.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4836682&req=5

pone.0153993.g009: The site of the mutation in the S1-24 mutant and phylogenetic analysis of OsCESA7.(A) Multiple alignments of the N-terminal region of 11 members of the OsCESA family and 8 members of the AtCESA family. The mutated residue (cysteine 40) is highly conserved. (B) Phylogenetic analysis of CESAs. The scale bar is an indicator of genetic distance based on branch length.
Mentions: Multiple alignments revealed that the mutation site (cysteine) at amino acid position 40 of OsCESA7 in the S1-24 mutant is highly conserved in 19 of 21 members of the OsCESA and AtCESA gene families (Fig 9A, S3 Table). This strong conservation indicates that this residue in the OsCESA zinc finger domain is important and necessary. We analyzed the evolutionary relationships among the CESA families in rice and Arabidopsis. As shown in Fig 9B, CESA members clustered into several clades. OsCESA4, OsCESA7, and OsCESA9, for which mutants have been identified and characterized [14–17], belonged to a monophyletic clade and was most closely related to AtCESA8, AtCESA4, and AtCESA7, respectively, while other CESAs were distributed in clades of three or four members. These results indicate that functions of some CESA members are redundant and that others are distinctive. Cellulose synthesis requires the cooperation of at least two to three different CESA gene family members [4, 6]. Diverse CESA genes would enable the formation of multiple subunit complexes essential for cellulose synthesis in cell wall biosynthesis.

Bottom Line: The brittle culms resulted from reduced mechanical strength due to a defect in thickening of the sclerenchyma cell wall and reduced cellulose content in the culms of the S1-24 mutant.The OsCESA7 gene is expressed predominantly in the culm at the mature stage, particularly in mechanical tissues such as vascular bundles and sclerenchyma cells, consistent with the brittle phenotype in the culm.These results indicate that OsCESA7 plays an important role in cellulose biosynthesis and plant growth.

View Article: PubMed Central - PubMed

Affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.

ABSTRACT
Rice is a model plant species for the study of cellulose biosynthesis. We isolated a mutant, S1-24, from ethyl methanesulfonate (EMS)-treated plants of the japonica rice cultivar, Nipponbare. The mutant exhibited brittle culms and other pleiotropic phenotypes such as dwarfism and partial sterility. The brittle culms resulted from reduced mechanical strength due to a defect in thickening of the sclerenchyma cell wall and reduced cellulose content in the culms of the S1-24 mutant. Map-based gene cloning and a complementation assay showed that phenotypes of the S1-24 mutant were caused by a recessive point mutation in the OsCESA7 gene, which encodes cellulose synthase A subunit 7. The missense mutation changed the highly conserved C40 to Y in the zinc finger domain. The OsCESA7 gene is expressed predominantly in the culm at the mature stage, particularly in mechanical tissues such as vascular bundles and sclerenchyma cells, consistent with the brittle phenotype in the culm. These results indicate that OsCESA7 plays an important role in cellulose biosynthesis and plant growth.

No MeSH data available.


Related in: MedlinePlus