title: Visualization of embolism formation in the xylem of liana stems using neutron radiography.
abstract: OBJECTIVE
  Cold neutron radiography was applied to directly observe embolism in conduits of liana stems with the aim to evaluate the suitability of this method for studying embolism formation and repair. Potential advantages of this method are a principally non-invasive imaging approach with low energy dose compared with synchrotron X-ray radiation, a good spatial and temporal resolution, and the possibility to observe the entire volume of stem portions with a length of several centimetres at one time.
  
  
  METHODS
  Complete and cut stems of Adenia lobata, Aristolochia macrophylla and Parthenocissus tricuspidata were radiographed at the neutron imaging facility CONRAD at the Helmholtz-Zentrum Berlin für Materialien und Energie, with each measurement cycle lasting several hours. Low attenuation gas spaces were separated from the high attenuation (water-containing) plant tissue using image processing.
  
  
  RESULTS
  Severe cuts into the stem were necessary to induce embolism. The formation and temporal course of an embolism event could then be successfully observed in individual conduits. It was found that complete emptying of a vessel with a diameter of 100 µm required a time interval of 4 min. Furthermore, dehydration of the whole stem section could be monitored via decreasing attenuation of the neutrons.
  
  
  CONCLUSIONS
  The results suggest that cold neutron radiography represents a useful tool for studying water relations in plant stems that has the potential to complement other non-invasive methods.
authors: Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. christian.toetzke@helmholtz-berlin.de
authors: Christian
authors: C
authors: Tötzke
authors: Tatiana
authors: T
authors: Miranda
authors: Wilfried
authors: W
authors: Konrad
authors: Julien
authors: J
authors: Gout
authors: Nikolay
authors: N
authors: Kardjilov
authors: Martin
authors: M
authors: Dawson
authors: Ingo
authors: I
authors: Manke
authors: Anita
authors: A
authors: Roth-Nebelsick
mesh_terms: D030022:Aristolochia / Q000033:anatomy & histology / Q000254:growth & development; D009502:Neutrons; D018547:Plant Stems; D011859:Radiography / Q000379:methods*; D027844:Vitaceae / Q000033:anatomy & histology / Q000254:growth & development; D052584:Xylem / Q000033:anatomy & histology*
references: New Phytol. 2010 Dec;188(4):1085-98
references: 20735745
references: Plant Physiol. 2007 Jun;144(2):1157-65
references: 17449653
references: Funct Plant Biol. 2006 Nov;33(11):1063-1074
references: 32689317
references: Ann Bot. 2003 Mar;91(4):419-28
references: 12588721
references: Plant Cell Environ. 2006 Sep;29(9):1715-29
references: 16913861
references: Plant Physiol. 2001 May;126(1):27-31
references: 11351066
references: Ann Bot. 2008 Mar;101(4):595-602
references: 18077466
references: Tree Physiol. 2001 Jan;21(1):27-33
references: 11260821
references: Plant Physiol. 1987 Feb;83(2):414-7
references: 16665259
references: Plant Sci. 2011 Apr;180(4):604-11
references: 21421408
references: Plant Physiol. 1999 May;120(1):11-22
references: 10318679
references: J Exp Bot. 2001 Jul;52(360):1527-36
references: 11457913
references: Oecologia. 1990 Oct;84(4):544-552
references: 28312972
references: J Exp Bot. 2012 Apr;63(7):2645-53
references: 22268159
references: Plant Physiol. 2010 Nov;154(3):1088-95
references: 20841451