title: Maintenance of xylem Network Transport Capacity: A Review of Embolism Repair in Vascular Plants.
abstract: Maintenance of long distance water transport in xylem is essential to plant health and productivity. Both biotic and abiotic environmental conditions lead to embolism formation within the xylem resulting in lost transport capacity and ultimately death. Plants exhibit a variety of strategies to either prevent or restore hydraulic capacity through cavitation resistance with specialized anatomy, replacement of compromised conduits with new growth, and a metabolically active embolism repair mechanism. In recent years, mounting evidence suggests that metabolically active cells surrounding the xylem conduits in some, but not all, species are capable of restoring hydraulic conductivity. This review summarizes our current understanding of the osmotically driven embolism repair mechanism, the known genetic and anatomical components related to embolism repair, rehydration pathways through the xylem, and the role of capacitance. Anatomical differences between functional plant groups may be one of the limiting factors that allow some plants to refill while others do not, but further investigations are necessary to fully understand this dynamic process. Finally, xylem networks should no longer be considered an assemblage of dead, empty conduits, but instead a metabolically active tissue finely tuned to respond to ever changing environmental cues.
authors: Horticultural Sciences Department, Citrus Research and Education Center, University of Florida Lake Alfred, FL, USA.
authors: Craig R
authors: CR
authors: Brodersen
authors: Andrew J
authors: AJ
authors: McElrone
keywords: biophysics; drought tolerance; ecophysiology of plants; embolism; xylem transport
references: Am J Bot. 2011 Jun;98(6):1007-15
references: 21613067
references: Oecologia. 1997 Apr;110(2):191-196
references: 28307424
references: Plant Physiol. 2007 Jun;144(2):1157-65
references: 17449653
references: Int J Mol Sci. 2012 Dec 24;14(1):359-77
references: 23263667
references: J Exp Bot. 2002 May;53(371):1155-61
references: 11971926
references: Ann Bot. 2008 Mar;101(4):595-602
references: 18077466
references: Plant Physiol. 1986 Oct;82(2):597-9
references: 16665075
references: Plant Physiol. 1998 Aug;117(4):1463-71
references: 9701601
references: Plant Sci. 2011 Apr;180(4):604-11
references: 21421408
references: New Phytol. 2009;184(1):245-256
references: 19563443
references: Phytopathology. 2012 Sep;102(9):827-40
references: 22713076
references: New Phytol. 2012 Jul;195(1):40-6
references: 22594675
references: Funct Plant Biol. 2009 Sep;36(9):815-825
references: 32688691
references: New Phytol. 2010 Oct;188(2):533-42
references: 20673281
references: Am J Bot. 2000 Sep;87(9):1272-8
references: 10991898
references: Proc Natl Acad Sci U S A. 2009 Jun 30;106(26):E68; author reply e69
references: 19506239
references: Oecologia. 1996 Mar;105(4):435-439
references: 28307135
references: Science. 2005 Dec 23;310(5756):1924
references: 16373568
references: Plant Cell Environ. 2011 Mar;34(3):514-24
references: 21118423
references: Am J Bot. 2009 Aug;96(8):1388-98
references: 21628286
references: Plant Cell Environ. 2009 Jul;32(7):882-92
references: 19302173
references: Plant Biol (Stuttg). 2008 Sep;10(5):604-23
references: 18761499
references: Tree Physiol. 1990 Dec;6(4):393-407
references: 14972931
references: Plant Cell Environ. 2009 Jul;32(7):828-36
references: 19220781
references: J Exp Bot. 2011 Jul;62(11):3885-94
references: 21447755
references: J Exp Bot. 2001 Jul;52(360):1527-36
references: 11457913
references: Plant Physiol. 1988 Nov;88(3):574-80
references: 16666351
references: Nature. 2004 Apr 22;428(6985):851-4
references: 15103376
references: Proc Natl Acad Sci U S A. 2008 Aug 12;105(32):11248-53
references: 18678893
references: Plant Physiol. 2012 Oct;160(2):955-64
references: 22837359
references: Plant Sci. 2012 Oct;195:48-53
references: 22920998
references: Tree Physiol. 2012 Jun;32(6):764-75
references: 22302370
references: Tree Physiol. 2003 Sep;23(13):907-14
references: 14532014
references: Funct Plant Biol. 2006 Nov;33(11):1063-1074
references: 32689317
references: Plant Cell Environ. 2006 Jan;29(1):26-35
references: 17086750
references: Am J Bot. 2009 Jul;96(7):1205-21
references: 21628270
references: Tree Physiol. 2012 Apr;32(4):414-22
references: 22499596
references: Plant Physiol. 2010 Oct;154(2):887-98
references: 20639405
references: New Phytol. 2010 Apr;186(2):274-81
references: 20409184
references: Tree Physiol. 2010 May;30(5):608-17
references: 20368339
references: New Phytol. 1996 Jan;132(1):47-56
references: 33863062
references: Am J Bot. 2008 Dec;95(12):1498-505
references: 21628157
references: Plant Cell Environ. 2006 Sep;29(9):1715-29
references: 16913861
references: Am J Bot. 1999 Oct;86(10):1367-72
references: 10523278
references: Physiol Plant. 2008 Aug;133(4):755-64
references: 18346074
references: Tree Physiol. 2012 Jul;32(7):880-93
references: 22684354
references: New Phytol. 2008;178(4):719-739
references: 18422905
references: Plant Physiol. 2001 May;126(1):27-31
references: 11351066
references: Tree Physiol. 2001 Sep;21(15):1123-32
references: 11581019
references: Am J Bot. 1997 Sep;84(9):1223
references: 21708677
references: Plant Cell Environ. 2010 Aug 1;33(8):1285-97
references: 20302602
references: Oecologia. 2001 Jan;126(2):182-192
references: 28547616
references: Plant Physiol. 2011 Nov;157(3):1419-29
references: 21951466
references: Am J Bot. 2007 Apr;94(4):640-9
references: 21636432
references: Planta. 2012 Jun;235(6):1383-96
references: 22241135
references: Plant Physiol. 2010 Nov;154(3):1088-95
references: 20841451
references: Plant Cell Environ. 2008 May;31(5):658-66
references: 18266903
references: Am J Bot. 2005 Dec;92(12):1970-4
references: 21646115
references: Plant Physiol. 2013 Apr;161(4):1820-9
references: 23463781
references: Am J Bot. 2013 Feb;100(2):374-83
references: 23328691
references: Oecologia. 2009 Sep;161(3):449-59
references: 19585154
references: Plant Physiol. 2011 Mar;155(3):1051-9
references: 21239620
references: New Phytol. 2009;183(1):142-152
references: 19368668
references: Ecol Lett. 2012 Jul;15(7):666-72
references: 22489611
references: Tree Physiol. 2001 Jan;21(1):27-33
references: 11260821
references: Plant Physiol. 1987 Feb;83(2):414-7
references: 16665259
references: J Exp Bot. 2008;59(10):2649-57
references: 18487632
references: Trends Plant Sci. 2009 Oct;14(10):530-4
references: 19726217
references: Plant Physiol. 2003 Oct;133(2):630-41
references: 14526109
references: Physiol Plant. 2013 Mar;147(3):329-39
references: 22686493
references: Plant Physiol. 1999 May;120(1):11-22
references: 10318679
references: Nature. 2012 Nov 29;491(7426):752-5
references: 23172141
references: Plant Physiol. 1986 Jan;80(1):110-6
references: 16664563
references: New Phytol. 2007;174(3):626-636
references: 17447917
references: Funct Plant Biol. 2007 Mar;34(2):95-111
references: 32689336
references: Plant Physiol. 1999 Mar;119(3):1001-8
references: 10069837