title: 2, 6-Dichlorobenzonitrile causes multiple effects on pollen tube growth beyond altering cellulose synthesis in Pinus bungeana Zucc.
abstract: Cellulose is an important component of cell wall, yet its location and function in pollen tubes remain speculative. In this paper, we studied the role of cellulose synthesis in pollen tube elongation in Pinus bungeana Zucc. by using the specific inhibitor, 2, 6-dichlorobenzonitrile (DCB). In the presence of DCB, the growth rate and morphology of pollen tubes were distinctly changed. The organization of cytoskeleton and vesicle trafficking were also disturbed. Ultrastructure of pollen tubes treated with DCB was characterized by the loose tube wall and damaged organelles. DCB treatment induced distinct changes in tube wall components. Fluorescence labeling results showed that callose, and acidic pectin accumulated in the tip regions, whereas there was less cellulose when treated with DCB. These results were confirmed by FTIR microspectroscopic analysis. In summary, our findings showed that inhibition of cellulose synthesis by DCB affected the organization of cytoskeleton and vesicle trafficking in pollen tubes, and induced changes in the tube wall chemical composition in a dose-dependent manner. These results confirm that cellulose is involved in the establishment of growth direction of pollen tubes, and plays important role in the cell wall construction during pollen tube development despite its lower quantity.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Huaiqing
authors.initials: H
authors.lastname: Hao
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Lusheng
authors.initials: L
authors.lastname: Fan
authors.forename: Ruili
authors.initials: R
authors.lastname: Li
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wang
mesh_terms: D002482:Cellulose / Q000096:biosynthesis*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D005453:Fluorescence; D018525:Germination / Q000187:drug effects; D005936:Glucans / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology*; D010368:Pectins / Q000378:metabolism; D028223:Pinus / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development* / Q000648:ultrastructure; D053205:Pollen Tube / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D011726:Pyridinium Compounds / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
chemical_list: C092350:FM 4-64; D005936:Glucans; D009570:Nitriles; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D010368:Pectins; D002482:Cellulose; C048306:callose; C055869:dichlobanil