title: Indaziflam herbicidal action: a potent cellulose biosynthesis inhibitor.
abstract: Cellulose biosynthesis is a common feature of land plants. Therefore, cellulose biosynthesis inhibitors (CBIs) have a potentially broad-acting herbicidal mode of action and are also useful tools in decoding fundamental aspects of cellulose biosynthesis. Here, we characterize the herbicide indaziflam as a CBI and provide insight into its inhibitory mechanism. Indaziflam-treated seedlings exhibited the CBI-like symptomologies of radial swelling and ectopic lignification. Furthermore, indaziflam inhibited the production of cellulose within <1 h of treatment and in a dose-dependent manner. Unlike the CBI isoxaben, indaziflam had strong CBI activity in both a monocotylonous plant (Poa annua) and a dicotyledonous plant (Arabidopsis [Arabidopsis thaliana]). Arabidopsis mutants resistant to known CBIs isoxaben or quinoxyphen were not cross resistant to indaziflam, suggesting a different molecular target for indaziflam. To explore this further, we monitored the distribution and mobility of fluorescently labeled CELLULOSE SYNTHASE A (CESA) proteins in living cells of Arabidopsis during indaziflam exposure. Indaziflam caused a reduction in the velocity of YELLOW FLUORESCENT PROTEIN:CESA6 particles at the plasma membrane focal plane compared with controls. Microtubule morphology and motility were not altered after indaziflam treatment. In the hypocotyl expansion zone, indaziflam caused an atypical increase in the density of plasma membrane-localized CESA particles. Interestingly, this was accompanied by a cellulose synthase interacting1-independent reduction in the normal coincidence rate between microtubules and CESA particles. As a CBI, for which there is little evidence of evolved weed resistance, indaziflam represents an important addition to the action mechanisms available for weed management.
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.).
authors: Chad
authors: C
authors: Brabham
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.).
authors: Lei
authors: L
authors: Lei
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.).
authors: Ying
authors: Y
authors: Gu
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.).
authors: Jozsef
authors: J
authors: Stork
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.).
authors: Michael
authors: M
authors: Barrett
authors: Departments of Horticulture (C.B., J.S., S.D.) and Plant and Soil Science (M.B.), University of Kentucky, Lexington, Kentucky 40546; andDepartment of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802 (L.L., Y.G.) sdebo2@uky.edu.
authors: Seth
authors: S
authors: DeBolt
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D001549:Benzamides / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002482:Cellulose / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology*; D018546:Hypocotyl / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D007192:Indenes / Q000737:chemistry / Q000494:pharmacology*; D008870:Microtubules / Q000378:metabolism; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D031785:Poa / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D036226:Seedlings / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D014227:Triazines / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001549:Benzamides; D006540:Herbicides; D007192:Indenes; C571026:N-(2,3-dihydro-2,6-dimethyl-1H-inden-1-yl)-6-(1-fluoroethyl)-1,3,5-triazine-2,4-diamine; D010940:Plant Proteins; D014227:Triazines; C057467:isoxaben; D002482:Cellulose; D005964:Glucosyltransferases; C478648:cellulose synthase