Paul, Shanty

[["dc.bibliographiccitation.artnumber","plx067"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","AoB PLANTS"],["dc.bibliographiccitation.lastpage","18"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Paul, Shanty"],["dc.contributor.author","Wildhagen, Henning"],["dc.contributor.author","Janz, Dennis"],["dc.contributor.author","Polle, Andrea"],["dc.date.accessioned","2018-02-22T11:03:06Z"],["dc.date.available","2018-02-22T11:03:06Z"],["dc.date.issued","2018"],["dc.description.abstract","Climate change with increasing periods of drought is expected to reduce the yield of biomass crops such as poplars. To combat yield loss, it is important to better understand the molecular mechanisms that control growth under drought. Here, the goal was to resolve the drought-induced changes of active cytokinins, a main growth hormone in plants, at the tissue level in different cell types and organs of poplars (Populus×canescens) in comparison with growth, biomass, leaf shedding, photosynthesis and water potential. Since cytokinin response is mediated by type-A response regulators,ARR5::GUSreporter lines were used to map cytokinin activity histochemically. The expression ofPtaRR3andPtaRR10was examined in different stem sections. Young leaves showed strong cytokinin activity in the veins and low staining under drought stress, accompanied by diminished leaf expansion. Leaf scars, at positions where drought-shedding occurred, showed strong reduction of cytokinin activity. The pith in the differentiation zone of stem showed high cytokinin activity with distinct, very active parenchymatic cells and enhanced activity close to primary xylem. This pattern was maintained under drought but the cytokinin activity was reduced. Mature phloem parenchymatic cells showed high cytokinin activity and mature wood showed no detectable cytokinin activity. Cytokinin activity in the cambium was apparent as a clear ring, which faded under drought. Xylem-localized cytokinin activities were also mirrored by the relative expression ofPtaRR3, whereasPtaRR10showed developmental but no drought-induced changes. Primary meristems exhibited high cytokinin activity regardless of drought stress, supporting a function of this phytohormone in meristem maintenance, whereas declining cytokinin activities in apical pith tissues and cambium of drought-stressed poplars linked cytokinin in these cell types with the control of primary and secondary growth processes. Changes in cytokinin activity further imply a role in drought avoidance mechanisms of poplars, especially in the reduction of leaf area."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2017"],["dc.identifier.doi","10.1093/aobpla/plx067"],["dc.identifier.pmid","29354257"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15020"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/12421"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.doi","10.1093/aobpla/plx067"],["dc.rights.access","openAccess"],["dc.subject.ddc","570"],["dc.title","Drought effects on the tissue- and cell-specific cytokinin activity in poplar"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","652"],["dc.bibliographiccitation.journal","Frontiers in Plant Science"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Paul, Shanty"],["dc.contributor.author","Wildhagen, Henning"],["dc.contributor.author","Janz, Dennis"],["dc.contributor.author","Teichmann, Thomas"],["dc.contributor.author","Hänsch, Robert"],["dc.contributor.author","Polle, Andrea"],["dc.date.accessioned","2017-11-28T10:03:37Z"],["dc.date.available","2017-11-28T10:03:37Z"],["dc.date.issued","2016"],["dc.description.abstract","Cytokinins play an important role in vascular development. But knowledge on the cellular localization of this growth hormone in the stem and other organs of woody plants is lacking. The main focus of this study was to investigate the occurrence and cellular localization of active cytokinins in leaves, roots, and along the stem of Populus × canescens and to find out how the pattern is changed between summer and winter. An ARR5::GUS reporter construct was used to monitor distribution of active cytokinins in different tissues of transgenic poplar lines. Three transgenic lines tested under outdoor conditions showed no influence of ARR5::GUS reporter construct on the growth performance compared with the wild-type, but one line lost the reporter activity. ARR5::GUS activity indicated changes in the tissue- and cell type-specific pattern of cytokinin activity during dormancy compared with the growth phase. ARR5::GUS activity, which was present in the root tips in the growing season, disappeared in winter. In the stem apex ground tissue, ARR5::GUS activity was higher in winter than in summer. Immature leaves from tissue-culture grown plants showed inducible ARR5::GUS activity. Leaf primordia in summer showed ARR5::GUS activity, but not the expanded leaves of outdoor plants or leaf primordia in winter. In stem cross sections, the most prominent ARR5::GUS activity was detected in the cortex region and in the rays of bark in summer and in winter. In the cambial zone the ARR5::GUS activity was more pronounced in the dormant than in growth phase. The pith and the ray cells adjacent to the vessels also displayed ARR5::GUS activity. In silico analyses of the tissue-specific expression patterns of the whole PtRR type-A family of poplar showed that PtRR10, the closest ortholog to the Arabidopsis ARR5 gene, was usually the most highly expressed gene in all tissues. In conclusion, gene expression and tissue-localization indicate high activity of cytokinins not only in summer, but also in winter. The presence of the signal in meristematic tissues supports their role in meristem maintenance. The reporter lines will be useful to study the involvement of cytokinins in acclimation of poplar growth to stress."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2016"],["dc.identifier.doi","10.3389/fpls.2016.00652"],["dc.identifier.fs","620096"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13292"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/10618"],["dc.language.iso","en"],["dc.notes.intern","DeepGreen Import"],["dc.notes.status","final"],["dc.publisher","Frontiers Media S.A."],["dc.relation.eissn","1664-462X"],["dc.rights","http://creativecommons.org/licenses/by/4.0/"],["dc.rights.access","openAccess"],["dc.title","Tissue- and Cell-Specific Cytokinin Activity in Populus × canescens Monitored by ARR5::GUS Reporter Lines in Summer and Winter"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","unknown"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]