title: Arabidopsis response to low-phosphate conditions includes active changes in actin filaments and PIN2 polarization and is dependent on strigolactone signalling.
abstract: Strigolactones (SLs) are plant hormones that regulate the plant response to phosphate (Pi) growth conditions. At least part of SL-signalling execution in roots involves MAX2-dependent effects on PIN2 polar localization in the plasma membrane (PM) and actin bundling and dynamics. We examined PIN2 expression, PIN2 PM localization, endosome trafficking, and actin bundling under low-Pi conditions: a MAX2-dependent reduction in PIN2 trafficking and polarization in the PM, reduced endosome trafficking, and increased actin-filament bundling were detected in root cells. The intracellular protein trafficking that is related to PIN proteins but unassociated with AUX1 PM localization was selectively inhibited. Exogenous supplementation of the synthetic SL GR24 to a SL-deficient mutant (max4) led to depletion of PIN2 from the PM under low-Pi conditions. Accordingly, roots of mutants in MAX2, MAX4, PIN2, TIR3, and ACTIN2 showed a reduced low-Pi response compared with the wild type, which could be restored by auxin (for all mutants) or GR24 (for all mutants except max2-1). Changes in PIN2 polarity, actin bundling, and vesicle trafficking may be involved in the response to low Pi in roots, dependent on SL/MAX2 signalling.
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Nirali
authors.initials: N
authors.lastname: Pandya-Kumar
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Anandamoy
authors.initials: A
authors.lastname: Dam
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Hila
authors.initials: H
authors.lastname: Haor
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Einav
authors.initials: E
authors.lastname: Mayzlish-Gati
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Eduard
authors.initials: E
authors.lastname: Belausov
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Smadar
authors.initials: S
authors.lastname: Wininger
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Abu-Abied
authors.affiliation: School of Chemistry, the University of Sydney, NSW 2006, Australia.
authors.forename: Christopher S P
authors.initials: CS
authors.lastname: McErlean
authors.affiliation: School of Chemistry, the University of Sydney, NSW 2006, Australia.
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Bromhead
authors.affiliation: Dipartimento di Chimica, Turin University, 10125 Torino, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Prandi
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Kapulnik
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel hkoltai@agri.gov.il.
authors.forename: Hinanit
authors.initials: H
authors.lastname: Koltai
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007783:Lactones / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D021381:Protein Transport; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D007783:Lactones; D010710:Phosphates; D010937:Plant Growth Regulators; C435920:MAX2 protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis
keywords: Actin; PIN2; endocytosis; phosphate; root; strigolactone.