title: Phosphatidic acid regulates microtubule organization by interacting with MAP65-1 in response to salt stress in Arabidopsis.
abstract: Membrane lipids play fundamental structural and regulatory roles in cell metabolism and signaling. Here, we report that phosphatidic acid (PA), a product of phospholipase D (PLD), regulates MAP65-1, a microtubule-associated protein, in response to salt stress. Knockout of the PLDα1 gene resulted in greater NaCl-induced disorganization of microtubules, which could not be recovered during or after removal of the stress. Salt affected the association of MAP65-1 with microtubules, leading to microtubule disorganization in pldα1cells, which was alleviated by exogenous PA. PA bound to MAP65-1, increasing its activity in enhancing microtubule polymerization and bundling. Overexpression of MAP65-1 improved salt tolerance of Arabidopsis thaliana cells. Mutations of eight amino acids in MAP65-1 led to the loss of its binding to PA, microtubule-bundling activity, and promotion of salt tolerance. The pldα1 map65-1 double mutant showed greater sensitivity to salt stress than did either single mutant. These results suggest that PLDα1-derived PA binds to MAP65-1, thus mediating microtubule stabilization and salt tolerance. The identification of MAP65-1 as a target of PA reveals a functional connection between membrane lipids and the cytoskeleton in environmental stress signaling.
authors.affiliation: College of Life Sciences, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.forename: Tonglin
authors.initials: T
authors.lastname: Mao
authors.forename: Jianing
authors.initials: J
authors.lastname: Nie
authors.forename: Min
authors.initials: M
authors.lastname: Yan
authors.forename: Ming
authors.initials: M
authors.lastname: Yuan
authors.forename: Wenhua
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D004136:Dinitrobenzenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010712:Phosphatidic Acids / Q000378:metabolism*; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D055049:Salt Tolerance; D036226:Seedlings; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D013424:Sulfanilamides / Q000494:pharmacology; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; D004136:Dinitrobenzenes; C492901:MAP65-1 protein, Arabidopsis; D008869:Microtubule-Associated Proteins; D010712:Phosphatidic Acids; D013424:Sulfanilamides; D050257:Tubulin Modulators; D012965:Sodium Chloride; C012465:oryzalin; C582894:PLDA1 protein, Arabidopsis; D010739:Phospholipase D