title: Knockout of the AtCESA2 gene affects microtubule orientation and causes abnormal cell expansion in Arabidopsis.
abstract: Complete cellulose synthesis is required to form functional cell walls and to facilitate proper cell expansion during plant growth. AtCESA2 is a member of the cellulose synthase A family in Arabidopsis (Arabidopsis thaliana) that participates in cell wall formation. By analysis of transgenic seedlings, we demonstrated that AtCESA2 was expressed in all organs, except root hairs. The atcesa2 mutant was devoid of AtCESA2 expression, leading to the stunted growth of hypocotyls in seedlings and greatly reduced seed production in mature plants. These observations were attributed to alterations in cell size as a result of reduced cellulose synthesis in the mutant. The orientation of microtubules was also altered in the atcesa2 mutant, which was clearly observed in hypocotyls and petioles. Complementary expression of AtCESA2 in atcesa2 could rescue the mutant phenotypes. Together, we conclude that disruption of cellulose synthesis results in altered orientation of microtubules and eventually leads to abnormal plant growth. We also demonstrated that the zinc finger-like domain of AtCESA2 could homodimerize, possibly contributing to rosette assemblies of cellulose synthase A within plasma membranes.
authors.affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Chu
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Yiyue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhonghui
authors.initials: Z
authors.lastname: Zhang
authors.forename: Nouyan
authors.initials: N
authors.lastname: Zheng
authors.forename: Bojiao
authors.initials: B
authors.lastname: Yin
authors.forename: Hongyan
authors.initials: H
authors.lastname: Yan
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Yuan
authors.forename: Xiansheng
authors.initials: X
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Xie
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D049108:Cell Enlargement; D002473:Cell Wall / Q000378:metabolism / Q000648:ultrastructure; D019281:Dimerization; D005816:Genetic Complementation Test; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005966:Glucuronidase / Q000032:analysis; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D029681:Arabidopsis Proteins; D005964:Glucosyltransferases; C478648:cellulose synthase; D005966:Glucuronidase