Heilmann, Ingo

[["dc.bibliographiccitation.firstpage","453"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","The Plant Journal"],["dc.bibliographiccitation.lastpage","468"],["dc.bibliographiccitation.volume","65"],["dc.contributor.author","Ischebeck, Till"],["dc.contributor.author","Stenzel, Irene"],["dc.contributor.author","Hempel, Franziska"],["dc.contributor.author","Jin, X. U."],["dc.contributor.author","Mosblech, Alina"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T08:59:38Z"],["dc.date.available","2018-11-07T08:59:38Z"],["dc.date.issued","2011"],["dc.description.abstract","P>The regulation of pollen tube growth by the phospholipid phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P(2)) is not well understood. The Arabidopsis genome encodes two type A phosphatidylinositol-4-phosphate (PI4P) 5-kinases, PIP5K10 and PIP5K11, which are exclusively expressed in pollen and produce PtdIns(4,5)P(2)in vitro. Fluorescence-tagged PIP5K10 and PIP5K11 localized to lateral subapical plasma membrane microdomains in tobacco pollen tubes in a pattern closely resembling the distribution of PtdIns(4,5)P(2,) with the exception of notably weaker association at the extreme apex. Overexpression of PIP5K10 or PIP5K11 in tobacco pollen tubes resulted in severe tip swelling and altered actin fine structure similar to that reported for overexpression of tobacco Nt-Rac5, a monomeric GTPase known to regulate the actin cytoskeleton. Increased sensitivity of Arabidopsis pip5k10 pip5k11 double mutant pollen tubes to Latrunculin B (LatB) further supports a role for type A PI4P 5-kinases in controlling the actin cytoskeleton. Despite the disruption of both its type A PI4P 5-kinases, the pip5k10 pip5k11 double mutant was fertile, indicating that one of the remaining type B PI4P 5-kinase isoforms might be functionally redundant with PIP5K10 and PIP5K11. Antagonistic effects of PIP5K11 and the Nt-Rac5-specific guanine nucleotide dissociation inhibitor, Nt-RhoGDI2, on tip swelling observed in coexpression-titration experiments indicate a link between PtdIns(4,5)P(2) and Rac-signaling in pollen tubes. The data suggest that type A PI4P 5-kinases influence the actin cytoskeleton in pollen tubes in part by counteracting Nt-RhoGDI2, possibly contributing to the control of the pool of plasma membrane-associated Nt-Rac5."],["dc.description.sponsorship","German Research Foundation (DFG) [He3424/1]"],["dc.identifier.doi","10.1111/j.1365-313X.2010.04435.x"],["dc.identifier.isi","000286619000011"],["dc.identifier.pmid","21265898"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23950"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell Publishing, Inc"],["dc.relation.issn","0960-7412"],["dc.title","Phosphatidylinositol-4,5-bisphosphate influences Nt-Rac5-mediated cell expansion in pollen tubes of Nicotiana tabacum"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","249"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Molecular Plant"],["dc.bibliographiccitation.lastpage","261"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Mosblech, Alina"],["dc.contributor.author","Koenig, Sabine"],["dc.contributor.author","Stenzel, Irene"],["dc.contributor.author","Grzeganek, Peter"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T11:17:53Z"],["dc.date.available","2018-11-07T11:17:53Z"],["dc.date.issued","2008"],["dc.description.abstract","Various biochemical signals are implicated in Arabidopsis wound signalling, including jasmonic acid (JA), salicylic acid, auxin, and Ca2+. Here, we report on cross-talk of phytohormones with phosphoinositide signals not previously implicated in plant wound responses. Within 30 min of mechanical wounding of Arabidopsis rosette-leaves, the levels of the lipid-derived soluble inositolpolyphosphate, inositol 1,4,5-trisphosphate (InsP(3)), increased four to five-fold. Concomitantly, the precursor lipids, phosphatidylinositol 4,5-bisphosphate, phosphatidylinositol 4-phosphate and phosphatidylinositol transiently depleted, followed by re-synthesis after 30-60 min of stimulation. Increased InsP(3) levels with wounding coincided with JA increases over the first hours of stimulation. In dde2-2-mutant plants deficient in JA biosynthesis, no InsP(3) increase was observed upon wounding, indicating that JA was required for InsP(3) formation, and InsP(3) levels increased in wild-type plants challenged with sorbitol, increasing endogenous JA levels. In InsP 5-ptase plants with attenuated phosphoinositide signalling, the induction of wounding-inducible genes was diminished compared with wildtype plants, suggesting a role for phosphoinositide signalling in mediating plant wound responses. The gene-expression patterns suggest that phosphoinositides contribute to both JA-dependent and JA-independent aspects of wound signalling. Weight gain of Plutella xylostella caterpillars feeding on InsP 5-ptase plants was increased compared with that of caterpillars feeding on wild-type plants. The ecophysiological relevance of phosphoinositide signals in plant defense responses to herbivory is discussed in light of recent findings of inositolpolyphosphate involvement in phytohormone-receptor function."],["dc.description.sponsorship","German Research Foundation [He3424/1-3]"],["dc.identifier.doi","10.1093/mp/ssm028"],["dc.identifier.isi","000259103700006"],["dc.identifier.pmid","19825537"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54919"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1674-2052"],["dc.title","Phosphoinositide and inositolpolyphosphate signalling in defense responses of Arabidopsis thaliana challenged by mechanical wounding"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","452"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Plants"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Stenzel, Irene"],["dc.contributor.author","Ischebeck, Till"],["dc.contributor.author","Vu-Becker, Linh Hai"],["dc.contributor.author","Riechmann, Mara"],["dc.contributor.author","Krishnamoorthy, Praveen"],["dc.contributor.author","Fratini, Marta"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2021-04-14T08:26:23Z"],["dc.date.available","2021-04-14T08:26:23Z"],["dc.date.issued","2020"],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft"],["dc.identifier.doi","10.3390/plants9040452"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/81922"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.publisher","MDPI"],["dc.relation.eissn","2223-7747"],["dc.rights","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Coordinated Localization and Antagonistic Function of NtPLC3 and PI4P 5-Kinases in the Subapical Plasma Membrane of Tobacco Pollen Tubes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3627"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA"],["dc.bibliographiccitation.lastpage","3632"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","Loefke, Christian"],["dc.contributor.author","Zwiewka, Marta"],["dc.contributor.author","Heilmann, Ingo"],["dc.contributor.author","van Montagu, Marc C. E."],["dc.contributor.author","Teichmann, Thomas"],["dc.contributor.author","Friml, Jiri"],["dc.date.accessioned","2018-11-07T09:28:00Z"],["dc.date.available","2018-11-07T09:28:00Z"],["dc.date.issued","2013"],["dc.description.abstract","Gravitropic bending of plant organs is mediated by an asymmetric signaling of the plant hormone auxin between the upper and lower side of the respective organ. Here, we show that also another plant hormone, gibberellie acid (GA), shows asymmetric action during gravitropic responses. lmmunodetection using an antibody against GA and monitoring GA signaling output by downstream degradation of DELLA proteins revealed an asymmetric GA distribution and response with the maximum at the lower side of gravistimulated roots. Genetic or pharmacological manipulation of GA levels or response affects gravity-mediated auxin redistribution and root bending response. The higher GA levels at the lower side of the root correlate with increased amounts of PIN-FORMED2 (PIN2) auxin transporter at the plasma membrane. The observed increase in PIN2 stability is caused by a specific GA effect on trafficking of PIN proteins to lytic vacuoles that presumably occurs downstream of brefeldin A-sensitive endosomes. Our results suggest that asymmetric auxin distribution instructive for gravity-induced differential growth is consolidated by the asymmetric action of GA that stabilizes the PIN-dependent auxin stream along the lower side of gravistimulated roots."],["dc.identifier.doi","10.1073/pnas.1300107110"],["dc.identifier.isi","000315841900083"],["dc.identifier.pmid","23391733"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30671"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Natl Acad Sciences"],["dc.relation.issn","0027-8424"],["dc.title","Asymmetric gibberellin signaling regulates vacuolar trafficking of PIN auxin transporters during root gravitropism"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","837"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Plant Cell & Environment"],["dc.bibliographiccitation.lastpage","850"],["dc.bibliographiccitation.volume","32"],["dc.contributor.author","Bargmann, Bastiaan O. R."],["dc.contributor.author","Laxalt, Ana M."],["dc.contributor.author","Ter Riet, Bas"],["dc.contributor.author","Testerink, Christa"],["dc.contributor.author","Merquiol, Emmanuelle"],["dc.contributor.author","Mosblech, Alina"],["dc.contributor.author","Leon-Reyes, Antonio"],["dc.contributor.author","Pieterse, Corne M. J."],["dc.contributor.author","Haring, Michel A."],["dc.contributor.author","Heilmann, Ingo"],["dc.contributor.author","Bartels, Dorothea"],["dc.contributor.author","Munnik, Teun"],["dc.date.accessioned","2018-11-07T08:28:32Z"],["dc.date.available","2018-11-07T08:28:32Z"],["dc.date.issued","2009"],["dc.description.abstract","Plants respond to wounding by means of a multitude of reactions, with the purpose of stifling herbivore assault. Phospholipase D (PLD) has previously been implicated in the wounding response. Arabidopsis (Arabidopsis thaliana) AtPLD alpha 1 has been proposed to be activated in intact cells, and the phosphatidic acid (PA) it produces to serve as a precursor for jasmonic acid (JA) synthesis and to be required for wounding-induced gene expression. Independently, PLD activity has been reported to have a bearing on wounding-induced MAPK activation. However, which PLD isoforms are activated, where this activity takes place (in the wounded or non-wounded cells) and what exactly the consequences are is a question that has not been comprehensively addressed. Here, we show that PLD activity during the wounding response is restricted to the ruptured cells using (32)P(i)-labelled phospholipid analyses of Arabidopsis pld knock-out mutants and PLD-silenced tomato cell-suspension cultures. pld alpha 1 knock-out lines have reduced wounding-induced PA production, and the remainder is completely eliminated in a pld alpha 1/delta double knock-out line. Surprisingly, wounding-induced protein kinase activation, AtLOX2 gene expression and JA biosynthesis were not affected in these knock-out lines. Moreover, larvae of the Cabbage White butterfly (Pieris rapae) grew equally well on wild-type and the pld knock-out mutants."],["dc.identifier.doi","10.1111/j.1365-3040.2009.01962.x"],["dc.identifier.isi","000266601600007"],["dc.identifier.pmid","19220780"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16442"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell Publishing, Inc"],["dc.relation.issn","0140-7791"],["dc.title","Reassessing the role of phospholipase D in the Arabidopsis wounding response"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","189"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","European Journal of Lipid Science and Technology"],["dc.bibliographiccitation.lastpage","190"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T11:17:31Z"],["dc.date.available","2018-11-07T11:17:31Z"],["dc.date.issued","2008"],["dc.identifier.doi","10.1002/ejlt.200700288"],["dc.identifier.isi","000254495700001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54828"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1438-7697"],["dc.title","Phosphoinositides - a tale of heads and tails"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.subtype","letter_note"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1958"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","The FASEB Journal"],["dc.bibliographiccitation.lastpage","1967"],["dc.bibliographiccitation.volume","21"],["dc.contributor.author","Koenig, Sabine"],["dc.contributor.author","Mosblech, Alina"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T11:00:59Z"],["dc.date.available","2018-11-07T11:00:59Z"],["dc.date.issued","2007"],["dc.description.abstract","Function and development of eukaryotic cells require tight control of diverse physiological processes. Numerous cellular processes are regulated by polyphosphoinositides, which interact with protein partners or mediate release of the second messenger, inositol 1,4,5-trisphosphate (InsP3). Emerging evidence suggests that different regulatory or signaling functions of polyphosphoinositides may be orchestrated by the establishment of distinct subcellular pools; the principles underlying pool-formation are, however, not understood. Arabidopsis plants exhibit transient increases in polyphosphoinositides with hyperosmotic stress, providing a model for comparing constitutive and stress-inducible polyphosphoinositide pools. Using a combination of thin-layer-chromatography and gaschromatography, phospholipids from stressed and nonstressed Arabidopsis plants were analyzed for their associated fatty acids. Under nonstress conditions structural phospholipids and phosphatidylinositol contained 50-70 mol% polyunsaturated fatty acids (PUFA), whereas polyphosphoinositides were more saturated (10-20 mol% PUFA). With hyperosmotic stress polyphosphoinositides with up to 70 mol% PUFA were formed that differed from constitutive species and coincided with a transient loss in unsaturated phosphatidylinositol. The patterns indicate inducible turnover of an unsaturated phosphatidylinositol pool, which accumulates under standard conditions and is primed for phosphorylation on stimulation. Metabolic analysis of wild-type and transgenic plants disturbed in phosphoinositide metabolism suggests that, in contrast to saturated species, unsaturated polyphosphoinositides are channeled toward InsP3-production."],["dc.identifier.doi","10.1096/fj.06-7887com"],["dc.identifier.isi","000247500300006"],["dc.identifier.pmid","17327357"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51049"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Federation Amer Soc Exp Biol"],["dc.relation.issn","0892-6638"],["dc.title","Stress-inducible and constitutive phosphoinositide pools have distinctive fatty acid patterns in Arabidopsis thaliana"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","13"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","PROTOPLASMA"],["dc.bibliographiccitation.lastpage","31"],["dc.bibliographiccitation.volume","240"],["dc.contributor.author","Ischebeck, Till"],["dc.contributor.author","Seiler, Stephan"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T08:44:51Z"],["dc.date.available","2018-11-07T08:44:51Z"],["dc.date.issued","2010"],["dc.description.abstract","Phosphoinositides (PIs) are minor, but essential phospholipid constituents of eukaryotic membranes, and are involved in the regulation of various physiological processes. Recent genetic and cell biological advances indicate that PIs play important roles in the control of polar tip growth in plant cells. In root hairs and pollen tubes, PIs control directional membrane trafficking required for the delivery of cell wall material and membrane area to the growing tip. So far, the exact mechanisms by which PIs control polarity and tip growth are unresolved. However, data gained from the analysis of plant, fungal and animal systems implicate PIs in the control of cytoskeletal dynamics, ion channel activity as well as vesicle trafficking. The present review aims at giving an overview of PI roles in eukaryotic cells with a special focus on functions pertaining to the control of cell polarity. Comparative screening of plant and fungal genomes suggests diversification of the PI system with increasing organismic complexity. The evolutionary conservation of the PI system among eukaryotic cells suggests a role for PIs in tip growing cells in models where PIs so far have not been a focus of attention, such as fungal hyphae."],["dc.identifier.doi","10.1007/s00709-009-0093-0"],["dc.identifier.isi","000275750200003"],["dc.identifier.pmid","20091065"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?goescholar/4183"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20290"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","Wien"],["dc.relation.issn","0033-183X"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","At the poles across kingdoms: phosphoinositides and polar tip growth"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4894"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","The Plant Cell"],["dc.bibliographiccitation.lastpage","4911"],["dc.bibliographiccitation.volume","25"],["dc.contributor.author","Ischebeck, Till"],["dc.contributor.author","Werner, Stephanie"],["dc.contributor.author","Krishnamoorthy, Praveen"],["dc.contributor.author","Lerche, Jennifer"],["dc.contributor.author","Meijon, Monica"],["dc.contributor.author","Stenzel, Irene"],["dc.contributor.author","Loefke, Christian"],["dc.contributor.author","Wiessner, Theresa"],["dc.contributor.author","Im, Yang Ju"],["dc.contributor.author","Perera, Imara Y."],["dc.contributor.author","Iven, Tim"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Busch, Wolfgang"],["dc.contributor.author","Boss, Wendy F."],["dc.contributor.author","Teichmann, Thomas"],["dc.contributor.author","Hause, Bettina"],["dc.contributor.author","Persson, Staffan"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T09:16:43Z"],["dc.date.available","2018-11-07T09:16:43Z"],["dc.date.issued","2013"],["dc.description.abstract","The functions of the minor phospholipid phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P-2] during vegetative plant growth remain obscure. Here, we targeted two related phosphatidylinositol 4-phosphate 5-kinases (PI4P 5-kinases) PIP5K1 and PIP5K2, which are expressed ubiquitously in Arabidopsis thaliana. A pip5k1 pip5k2 double mutant with reduced PtdIns(4,5)P-2 levels showed dwarf stature and phenotypes suggesting defects in auxin distribution. The roots of the pip5k1 pip5k2 double mutant had normal auxin levels but reduced auxin transport and altered distribution. Fluorescence-tagged auxin efflux carriers PIN-FORMED (PIN1)-green fluorescent protein (GFP) and PIN2-GFP displayed abnormal, partially apolar distribution. Furthermore, fewer brefeldin A-induced endosomal bodies decorated by PIN1-GFP or PIN2-GFP formed in pip5k1 pip5k2 mutants. Inducible overexpressor lines for PIP5K1 or PIP5K2 also exhibited phenotypes indicating misregulation of auxin-dependent processes, and immunolocalization showed reduced membrane association of PIN1 and PIN2. PIN cycling and polarization require clathrin-mediated endocytosis and labeled clathrin light chain also displayed altered localization patterns in the pip5k1 pip5k2 double mutant, consistent with a role for PtdIns(4,5)P-2 in the regulation of clathrin-mediated endocytosis. Further biochemical tests on subcellular fractions enriched for clathrin-coated vesicles (CCVs) indicated that pip5k1 and pip5k2 mutants have reduced CCV-associated PI4P 5-kinase activity. Together, the data indicate an important role for PtdIns(4,5)P-2 in the control of clathrin dynamics and in auxin distribution in Arabidopsis."],["dc.identifier.doi","10.1105/tpc.113.116582"],["dc.identifier.isi","000330611200014"],["dc.identifier.pmid","24326589"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27998"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Plant Biologists"],["dc.relation.issn","1532-298X"],["dc.relation.issn","1040-4651"],["dc.title","Phosphatidylinositol 4,5-Bisphosphate Influences PIN Polarization by Controlling Clathrin-Mediated Membrane Trafficking in Arabidopsis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3312"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","The Plant Cell"],["dc.bibliographiccitation.lastpage","3330"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Ischebeck, Till"],["dc.contributor.author","Stenzel, Irene"],["dc.contributor.author","Heilmann, Ingo"],["dc.date.accessioned","2018-11-07T11:08:50Z"],["dc.date.available","2018-11-07T11:08:50Z"],["dc.date.issued","2008"],["dc.description.abstract","Phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P(2)] occurs in the apical plasma membrane of growing pollen tubes. Because enzymes responsible for PtdIns(4,5) P(2) production at that location are uncharacterized, functions of PtdIns( 4,5) P(2) in pollen tube tip growth are unresolved. Two candidate genes encoding pollen-expressed Arabidopsis thaliana phosphatidylinositol-4-phosphate 5-kinases (PI4P 5-kinases) of Arabidopsis subfamily B were identified (PIP5K4 and PIP5K5), and their recombinant proteins were characterized as being PI4P 5-kinases. Pollen of T-DNA insertion lines deficient in both PIP5K4 and PIP5K5 exhibited reduced pollen germination and defects in pollen tube elongation. Fluorescence-tagged PIP5K4 and PIP5K5 localized to an apical plasma membrane microdomain in Arabidopsis and tobacco (Nicotiana tabacum) pollen tubes, and overexpression of either PIP5K4 or PIP5K5 triggered multiple tip branching events. Further studies using the tobacco system revealed that overexpression caused massive apical pectin deposition accompanied by plasma membrane invaginations. By contrast, callose deposition and cytoskeletal structures were unaltered in the overexpressors. Morphological effects depended on PtdIns(4,5) P(2) production, as an inactive enzyme variant did not produce any effects. The data indicate that excessive PtdIns(4,5) P2 production by type B PI4P 5-kinases disturbs the balance of membrane trafficking and apical pectin deposition. Polar tip growth of pollen tubes may thus be modulated by PtdIns(4,5) P(2) via regulatory effects on membrane trafficking and/or apical pectin deposition."],["dc.description.sponsorship","German Research Foundation"],["dc.identifier.doi","10.1105/tpc.108.059568"],["dc.identifier.isi","000262861700015"],["dc.identifier.pmid","19060112"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52881"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Plant Biologists"],["dc.relation.issn","1040-4651"],["dc.title","Type B Phosphatidylinositol-4-Phosphate 5-Kinases Mediate Arabidopsis and Nicotiana tabacum Pollen Tube Growth by Regulating Apical Pectin Secretion"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]