The aim of this study was to understand the role of bark water uptake in xylem embolism vessel refilling in Salix matsudana. Isolated branch segments of Salix matsudana were soaked in deionized water. Next, the percent loss of conductivity (PLC), the volume, the osmotic potential (Ψs), the concentrations of soluble sugar and ions in xylem sap and the concentration of NSC in the xylem were measured after 2, 4 and 6 h. The PLC decreased, and the volume of xylem sap increased, compared with initial values after soaking for 2, 4, and 6 h. Moreover, the osmotic potential (Ψs) of xylem sap decreased. The concentrations of ions and soluble sugar in the xylem sap increased significantly compared with the initial concentrations after soaking. Based on our findings, water not only entered the xylem vessels through the bark but also repaired the embolism of branches in a certain time. These findings will contribute to the understanding of the physiological and molecular mechanisms between bark water uptake and embolism repair.

Ji Xia, Sun Zhongkui, Cheng Tiantian, Yan Yu, Yu Yongchang. Osmotic regulation mediates embolism vessel refilling via bark water uptake in Salix Matsudana. Academic Journal of Environment & Earth Science (2022) Vol. 4 Issue 1: 55-61. https://doi.org/10.25236/AJEE.2022.040111.

[1] Tyree MT, Zimmermann MH (2002) Xylem Structure and the Ascent of Sap. Springer, Berlin. 45–56

[2] Martorell S, DIAZ-ESPEJO A, Medrano H, Ball MC, Choat B (2014) Rapid hydraulic recovery in Eucalyptus pauciflora after drought: linkages between stem hydraulics and leaf gas exchange. Plant Cell Environ 37: 617–626

[3] Urli M, Porte AJ, Cochard H, Guengant Y, Burlett R, Delzon S (2013) Xylem embolism threshold for catastrophic hydraulic failure in angiosperm trees. Tree Physiol 33: 672–683

[4] Wheeler JK, Huggett BA, Tofte AN, Rockwell FE, Holbrook NM (2013) Cutting xylem under tension or supersaturated with gas can generate PLC and the appearance of rapid recovery from embolism. Plant Cell Environ 36: 1938–1949

[5] Brodersen CR, Mcelrone AJ, choat B, lee F, Shackel Ka, Matthews Ma (2013) In vivo visualizations of drought-induced embolism spread in Vitis vinifera. Plant Physiol 161:1820–1829

[6] Rolland V, Dana MB, Lenné T, Bryant G, Chen H, Wolfe J, Holbrook NM, Stanton DE, Ball MC (2015) Easy come, easy go: Capillary forces enable rapid refilling of embolized primary xylem vessels. Plant Physiol 168: 1636–1647

[7] Brodribb TJ, Pittermann J, Coomes DA (2012) Elegance versus speed: Examining the competition between conifer and angiosperm trees. Int J Plant Sci 173: 673–694

[8] Nardini A, Lo Gullo MA, Salleo S (2011) Refilling embolized xylem conduits: Is it a matter of phloem unloading? Plant Sci 180: 604–611

[9] Secchi F, Zwieniecki MA (2010) Patterns of PIP gene expression in Populus trichocarpa during recovery from xylem embolism suggest a major role for the PIP1 aquaporin subfamily as moderators of refilling process. Plant Cell Environ 33: 1285–1297

[10] Mayr S, Schmid P, Laur J, Rosner S, Charra-Vaskou K, Daemon B, Hacke U (2014) Uptake of water via branches helps timberline conifers refill embolized xylem in late winter. Plant Physiol 164: 1731–1740

[11] Secchi F, Zwieniecki MA (2011) Sensing embolism in xylem vessels: The role of sucrose as a trigger for refilling. Plant Cell Environ 34: 514–524

[12] Salleo S, Trifilo P, Esposito S, Nardini A, Lo Gullo MA (2009) Starch-to-sugar conversion in wood parenchyma of field-growing Laurus nobilis plants: A component of the signal pathway for embolism repair? Funct Plant Biol 36: 815–825