%0 Journal Article %1 Salleoetal_04 %A Salleo, S. %A Lo Gullo, M. A. %A Triflio, P. %A Nardini, A. %D 2004 %J Plant, Cell and Environment %K bibtex-import, citeulikeExport embolism, refilling, solutes %P 1065--1076 %T New evidence for a role of vessel-associated cells and phloem in the rapid xylem re?lling of cavitated stems of @Laurus nobilis L. %V 27 %X Xylem recovery from embolism was studied in Laurus nobilis L. stems that were induced to cavitate by combining negative xylem pressure potentials (PX = -1.1 MPa) with positive air pressures (PC) applied using a pressure collar. Xylem re?lling was measured by recording the percentage loss of hydraulic conductance (PLC) with respect to the maximum 2 min, 20 min and 15 h after pressure release. Sodium orthovanadate (an inhibitor of many ATP-ases) strongly inhibited xylem re?lling while fusicoccin (a stimu- lator of the plasma membrane H+-ATPase) promoted com- plete embolism reversal. So, the re?lling process was interpreted to result from energy-dependent mechanisms. Stem girdling induced progressively larger inhibition to re?lling the nearer to the embolized stem segment phloem was removed. The starch content of wood parenchyma was estimated as percentages of ray and vasicentric cells with high starch content with respect to the total, before and after stem embolism was induced. A closely linear positive relationship was found to exist between recovery from PLC and starch hydrolysis. This, was especially evident in vasi- centric cells. A mechanism for xylem re?lling based upon starch to sugar conversion and transport into embolized conduits, assisted by phloem pressure-driven radial mass ?ow is proposed.

@article{Salleoetal_04, abstract = {{Xylem recovery from embolism was studied in Laurus nobilis L. stems that were induced to cavitate by combining negative xylem pressure potentials (PX = -1.1 MPa) with positive air pressures (PC) applied using a pressure collar. Xylem re?lling was measured by recording the percentage loss of hydraulic conductance (PLC) with respect to the maximum 2 min, 20 min and 15 h after pressure release. Sodium orthovanadate (an inhibitor of many ATP-ases) strongly inhibited xylem re?lling while fusicoccin (a stimu- lator of the plasma membrane H+-ATPase) promoted com- plete embolism reversal. So, the re?lling process was interpreted to result from energy-dependent mechanisms. Stem girdling induced progressively larger inhibition to re?lling the nearer to the embolized stem segment phloem was removed. The starch content of wood parenchyma was estimated as percentages of ray and vasicentric cells with high starch content with respect to the total, before and after stem embolism was induced. A closely linear positive relationship was found to exist between recovery from PLC and starch hydrolysis. This, was especially evident in vasi- centric cells. A mechanism for xylem re?lling based upon starch to sugar conversion and transport into embolized conduits, assisted by phloem pressure-driven radial mass ?ow is proposed.}}, added-at = {2019-03-31T01:14:40.000+0100}, author = {Salleo, S. and Lo Gullo, M. A. and Triflio, P. and Nardini, A.}, biburl = {https://www.bibsonomy.org/bibtex/22294d338a25846108310f18ced229c39/dianella}, citeulike-article-id = {1524011}, comment = {(private-note)inhibiting ATP hydrolysis and protein phosphorylation (Vanadanate inhibits phosphatases and ATPases ) inhibits short term recovery (20minutes), but it catches up after 15 hours Promoting the plasma membrane proton pump (FC specific for H+ ATP-ase) with fucococcin caused a rapid refilling of embolism not seen in control or KCl treated stems phloem removal (Girdling) near the pressure collar inhibited recovery, even after 15 hours more starch, more PLC. Starch hydrolysis -> recovery SO it's definitely an active refilling process. Speculation that the phloem pressure needs to be maintained and might drive mass flow into the xylem. Awesome paper.}, interhash = {20b418a87fabc34b939765e95fd71224}, intrahash = {2294d338a25846108310f18ced229c39}, journal = {Plant, Cell and Environment}, keywords = {bibtex-import, citeulikeExport embolism, refilling, solutes}, pages = {1065--1076}, posted-at = {2007-07-31 07:03:58}, priority = {2}, timestamp = {2019-03-31T01:16:26.000+0100}, title = {{New evidence for a role of vessel-associated cells and phloem in the rapid xylem re?lling of cavitated stems of @Laurus nobilis L.}}, volume = 27, year = 2004 }