The frequency and mechanisms behind drought-induced hydraulic failure in woody angiosperms from temperate to tropical biomes

• Applicant: Professor Dr. Steven Jansen
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 410768178

• Final Report Year: 2023

Final Report Abstract

Our project investigated the temporal frequency of embolism formation (i.e. air entry) in xylem tissue of woody angiosperms. This topic is relevant given current concerns about climate change, and the role of hydraulic failure in forest mortality and reduced crop productivity. We confirmed that embolism occurrence is rare, and only occurs under severe levels of drought. Moreover, we showed that stem and leaf xylem are equally resistant to embolism. We also improved and validated the pneumatic method to estimate embolism resistance based on experimental work and a gas diffusion kinetics model. Anatomical observations confirmed that the thickness of porous walls between water conducting cells plays an important role in embolism resistance, and that these walls gradually shrink over time. Shrinkage was found to be associated with increased stiffness in the liana species Clematis vitalba, and increased embolism resistance in grapevine. Finally, chemical analyses of xylem sap showed that polar xylem sap lipids are universal in angiosperms. We did not find significant differences in lipid concentrations and chemistry across field sites. There was also no evidence for seasonal changes in lipid composition at the temperate and tropical sites, suggesting that polar lipids in xylem sap originate from cytoplasmic remnants of living vessels. We showed that polar lipids are linked to nanobubbles in xylem sap, and that cell walls between conduits block transport of lipid micelles and lipidcoated nanobubbles.

Publications

• A semi-automated method for measuring xylem vessel length distribution. Theoretical and Experimental Plant Physiology, 32(4), 331-340.
  Pereira, Luciano; Miranda, Marcela T.; Pires, Gabriel S.; Pacheco, Vinícius S.; Guan, Xinyi; Kaack, Lucian; Karimi, Zohreh; Machado, Eduardo C.; Jansen, Steven; Tyree, Melvin T. & Ribeiro, Rafael V.
  
• An increase in xylem embolism resistance of grapevine leaves during the growing season is coordinated with stomatal regulation, turgor loss point and intervessel pit membranes. New Phytologist, 229(4), 1955-1969.
  Sorek, Yonatan; Greenstein, Smadar; Netzer, Yishai; Shtein, Ilana; Jansen, Steven & Hochberg, Uri
  
• The Pneumatron estimates xylem embolism resistance in angiosperms based on gas diffusion kinetics: a mini-review. Acta Horticulturae, 1300, 193-200.
  Jansen, S.; Guan, X.; Kaack, L.; Trabi, C.; Miranda, M.T.; Ribeiro, R.V. & Pereira, L.
  
• The role of porous media for water transport in plants. Invited Presentation at the German InterPore meeting, Stuttgart, 1-2 October 2020.
  Jansen S.
  
• Topography strongly affects drought stress and xylem embolism resistance in woody plants from a karst forest in Southwest China. Functional Ecology, 35(3), 566-577.
  Zhang, Qi‐Wei; Zhu, Shi‐Dan; Jansen, Steven & Cao, Kun‐Fang
  
• A User Manual to Measure Gas Diffusion Kinetics in Plants: Pneumatron Construction, Operation, and Data Analysis. Frontiers in Plant Science, 12.
  Trabi, Christophe L.; Pereira, Luciano; Guan, Xinyi; Miranda, Marcela T.; Bittencourt, Paulo R. L.; Oliveira, Rafael S.; Ribeiro, Rafael V. & Jansen, Steven
  
• How do plants transport water under negative pressure? Plenary Speaker at InterPore 2021, 13th annual meeting, 30 May – 04 June 2021, Edinburgh, U.K.
  Jansen S.
  
• Hydraulic prediction of drought‐induced plant dieback and top‐kill depends on leaf habit and growth form. Ecology Letters, 24(11), 2350-2363.
  Chen, Ya‐Jun; Choat, Brendan; Sterck, Frank; Maenpuen, Phisamai; Katabuchi, Masatoshi; Zhang, Shu‐Bin; Tomlinson, Kyle W.; Oliveira, Rafael S.; Zhang, Yong‐Jiang; Shen, Jing‐Xian; Cao, Kun‐Fang & Jansen, Steven
  
• Interfacial phenomena in plant xylem, a system under negative pressure. Botanical Society of America. Online meeting, 18-23 June, 2021
  Schenk H.J., Mocko K., Michaud J.M., Mora J.G., Kaack L., Guan X., Roth M.A., Welti R.A. & Jansen S.
  
• No gas source, no problem: Proximity to pre‐existing embolism and segmentation affect embolism spreading in angiosperm xylem by gas diffusion. Plant, Cell & Environment, 44(5), 1329-1345.
  Guan, Xinyi; Pereira, Luciano; McAdam, Scott A. M.; Cao, Kun‐Fang & Jansen, Steven
  
• Positive pressure in xylem and its role in hydraulic function. New Phytologist, 230(1), 27-45.
  Schenk, H. Jochen; Jansen, Steven & Hölttä, Teemu
  
• A crucial phase in plants – it's a gas, gas, gas!. New Phytologist, 233(4), 1556-1559.
  Jansen, Steven; Bittencourt, Paulo; Pereira, Luciano; Schenk, H. Jochen & Kunert, Norbert
  
• A unit pipe pneumatic model to simulate gas kinetics during measurements of embolism in excised angiosperm xylem. Tree Physiology, 43(1), 88-101.
  Yang, Dongmei; Pereira, Luciano; Peng, Guoquan; Ribeiro, Rafael V.; Kaack, Lucian; Jansen, Steven & Tyree, Melvin T.
  
• Nanoparticles are linked to polar lipids in xylem sap of temperate angiosperm species. Tree Physiology.
  Guan, Xinyi; Schenk, H. Jochen; Roth, Mary R.; Welti, Ruth; Werner, Julia; Kaack, Lucian; Trabi, Christophe L. & Jansen, Steven
  
• Reconciling discrepancies in measurements of vulnerability to xylem embolism with the pneumatic method. New Phytologist, 237(2), 374-383.
  Brum, Mauro; Pereira, Luciano; Ribeiro, Rafael Vasconcelos; Jansen, Steven; Bittencourt, Paulo R. L.; Oliveira, Rafael S. & Saleska, Scott R.
  
• Stem and leaf xylem of angiosperm trees experiences minimal embolism in temperate forests during two consecutive summers with moderate drought. Plant Biology, 24(7), 1208-1223.
  Guan, X.; Werner, J.; Cao, K.‐F.; Pereira, L.; Kaack, L.; McAdam, S. A. M. & Jansen, S.
  
• The functional significance of porous media and polar lipids for fluid transport in angiosperm xylem. 5th Xylem International Meeting, 19-21 September 2022, Würzburg
  Jansen S.
  
• Xylem embolism spread is largely prevented by interconduit pit membranes until the majority of conduits are gas‐filled. Plant, Cell & Environment, 45(4), 1204-1215.
  Avila, Rodrigo T.; Guan, Xinyi; Kane, Cade N.; Cardoso, Amanda A.; Batz, Timothy A.; DaMatta, Fábio M.; Jansen, Steven & McAdam, Scott A. M.
  
• Addressing controversies in the xylem embolism resistance–vessel diameter relationship. New Phytologist, 238(1), 283-296.
  Isasa, Emilie; Link, Roman Mathias; Jansen, Steven; Tezeh, Fon Robinson; Kaack, Lucian; Sarmento, Cabral Juliano & Schuldt, Bernhard
  
• Ageing-induced shrinkage of intervessel pit membranes in xylem of Clematis vitalba modifies its mechanical properties as revealed by atomic force microscopy. Frontiers in Plant Science, 14.
  Carmesin, Cora F.; Port, Fabian; Böhringer, Samuel; Gottschalk, Kay-Eberhard; Rasche, Volker & Jansen, Steven
  
• Lipid concentration and composition in xylem sap of woody angiosperms from a tropical savanna and a seasonal rainforest. Plant Diversity, 46(1), 126-133.
  Huang, Ling-Bo; Guan, Xinyi; Aritsara, Amy Ny Aina; Zhu, Jun-Jie; Jansen, Steven & Cao, Kun-Fang