title: Expression of MAX2 under SCARECROW promoter enhances the strigolactone/MAX2 dependent response of Arabidopsis roots to low-phosphate conditions.
abstract: MAX2/strigolactone signaling in the endodermis and/or quiescent center of the root is partially sufficient to exert changes in F-actin density and cellular trafficking in the root epidermis, and alter gene expression during plant response to low Pi conditions. Strigolactones (SLs) are a new group of plant hormones that regulate different developmental processes in the plant via MAX2, an F-box protein that interacts with their receptor. SLs and MAX2 are necessary for the marked increase in root-hair (RH) density in seedlings under conditions of phosphate (Pi) deprivation. This marked elevation was associated with an active reduction in actin-filament density and endosomal movement in root epidermal cells. Also, expression of MAX2 under the SCARECROW (SCR) promoter was sufficient to confer SL sensitivity in roots, suggesting that SL signaling pathways act through a root-specific, yet non-cell-autonomous regulatory mode of action. Here we show evidence for a non-cell autonomous signaling of SL/MAX2, originating from the root endodermis, and necessary for seedling response to conditions of Pi deprivation. SCR-derived expression of MAX2 in max2-1 mutant background promoted the root low Pi response, whereas supplementation of the synthetic SL GR24 to these SCR:MAX2 expressing lines further enhanced this response. Moreover, the SCR:MAX2 expression led to changes in actin density and endosome movement in epidermal cells and in TIR1 and PHO2 gene expression. These results demonstrate that MAX2 signaling in the endodermis and/or quiescent center is partially sufficient to exert changes in F-actin density and cellular trafficking in the epidermis, and alter gene expression under low Pi conditions.
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.|The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900, Ramat-Gan, Israel.
authors.forename: Ortal
authors.initials: O
authors.lastname: Madmon
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Moran
authors.initials: M
authors.lastname: Mazuz
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Puja
authors.initials: P
authors.lastname: Kumari
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Anandamoy
authors.initials: A
authors.lastname: Dam
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Aurel
authors.initials: A
authors.lastname: Ion
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Einav
authors.initials: E
authors.lastname: Mayzlish-Gati
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Eduard
authors.initials: E
authors.lastname: Belausov
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Smadar
authors.initials: S
authors.lastname: Wininger
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Abu-Abied
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Christopher S P
authors.initials: CS
authors.lastname: McErlean
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Bromhead
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900, Ramat-Gan, Israel.
authors.forename: Rafael
authors.initials: R
authors.lastname: Perl-Treves
authors.affiliation: Dipartimento di Chimica, Turin University, 10125, Turin, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Prandi
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Kapulnik
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel. hkoltai@volcani.agri.gov.il.
authors.forename: Hinanit
authors.initials: H
authors.lastname: Koltai
mesh_terms: D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D007783:Lactones / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015398:Signal Transduction
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D007783:Lactones; C435920:MAX2 protein, Arabidopsis; D010710:Phosphates; C100978:SCR protein, Arabidopsis
keywords: MAX2; Phosphate; Phosphate-starvation induced genes; Root; Root hair; SCARECROW; Strigolactones