Premium
Vulnerability to cavitation differs between current‐year and older xylem: non‐destructive observation with a compact magnetic resonance imaging system of two deciduous diffuse‐porous species
Author(s) -
Fukuda Kenji,
Kawaguchi Daichi,
Aihara Tomo,
Ogasa Mayumi Y.,
Miki Naoko H.,
Haishi Tomoyuki,
Umebayashi Toshihiro
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12510
Subject(s) - xylem , cavitation , betula platyphylla , materials science , deciduous , nuclear magnetic resonance , composite material , botany , biology , physics , acoustics
Development of xylem embolism during water stress in two diffuse‐porous hardwoods, K atsura ( C ercidiphyllum japonicum ) and J apanese white birch ( B etula platyphylla var. japonica ), was observed non‐destructively under a compact magnetic resonance imaging ( MRI ) system in addition to conventional quantitation of hydraulic vulnerability to cavitation from excised stem segments. Distribution of white and dark areas in MR images corresponded well to the distribution of water‐filled/embolized vessels observed by cryo‐scanning electron microscopy in both species. Water‐filled vessels were observed in MR images as white areas in K atsura and as white dots in J apanese white birch, respectively, and embolisms could be detected as a change to dark areas. The increase in the relative embolized area ( REA : %) in the cross‐sectional area of total xylem during water stress, which was estimated from the binarized MR images, was consistent with the hydraulic vulnerability curves of these species. From the non‐destructive MRI observations, cavitation induced by water stress was shown to develop earlier in 1‐ or 2‐year‐old xylem than in the current‐year xylem in both species; that is, the vulnerability to cavitation differs between vessels in the current‐year xylem and those in older annual rings.