Not all lipids in xylem conduits are artefacts. A reply to Yamagishi et al.

Replacing ultra-pure water solution with ion solution closer to the composition of natural xylem sap increases stem hydraulic conductance by up to 58%, likely due to changes in electroviscosity in the pit membrane pores. This effect has been proposed to contribute to the control of plant hydraulic and stomatal conductance and potentially to influence on carbon balance during dehydration. However, this effect has never been directly tested for leaf xylem, which constitutes a major bottleneck in the whole plant. We tested for an ion-mediated increase in the hydraulic conductance of the leaf xylem (Kx) for seven species diverse in phylogeny and drought tolerance. Across species, no significant changes in Kx were observed between 0 and 15 mM KCl. We further tested for an effect of ion solution during measurements of Kx vulnerability to dehydration in Quercus agrifolia and found no significant impact. These results for leaf xylem contrast with the often strong ion effect reported for stems, and we suggest several hypotheses to account for the difference, relating to the structure of xylem conduits across vein orders, and the ultrastructure of leaf xylem pores. A negligible ion response in leaves would weaken xylem sap ion-mediated control of plant hydraulic conductance, facilitating modeling of whole plant hydraulic behavior and its influence on productivity.

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Widening of xylem conduits in a conifer tree depends on the longer time of cell expansion downwards along the stem

Journal of Experimental Botany ◽

10.1093/jxb/err309 ◽

2011 ◽

Vol 63 (2) ◽

pp. 837-845 ◽

Cited By ~ 75

Author(s):

Tommaso Anfodillo ◽

Annie Deslauriers ◽

Roberto Menardi ◽

Laura Tedoldi ◽

Giai Petit ◽

...

Keyword(s):

Cell Expansion ◽

Conifer Tree ◽

Xylem Conduits

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Analysis of Non-Structural Carbohydrates and Xylem Anatomy of Leaf Petioles Offers New Insights in the Drought Response of Two Grapevine Cultivars

International Journal of Molecular Sciences ◽

10.3390/ijms21041457 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1457 ◽

Cited By ~ 2

Author(s):

Rachele Falchi ◽

Elisa Petrussa ◽

Enrico Braidot ◽

Paolo Sivilotti ◽

Francesco Boscutti ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Stress Response ◽

Stress Responses ◽

Cabernet Sauvignon ◽

Drought Response ◽

Xylem Anatomy ◽

Anatomical Analysis ◽

Starch Mobilization ◽

Xylem Conduits

In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.

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Induction of air embolism in xylem conduits of pre‐defined diameter

Journal of Experimental Botany ◽

10.1093/jexbot/52.358.981 ◽

2001 ◽

Vol 52 (358) ◽

pp. 981-991 ◽

Cited By ~ 23

Author(s):

W. Van Ieperen ◽

J. Nijsse ◽

C.J. Keijzer ◽

U. Van Meeteren

Keyword(s):

Air Embolism ◽

Xylem Conduits

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Comparative axial widening of phloem and xylem conduits in small woody plants

Trees ◽

10.1007/s00468-014-1006-1 ◽

2014 ◽

Vol 28 (3) ◽

pp. 915-921 ◽

Cited By ~ 34

Author(s):

Giai Petit ◽

Alan Crivellaro

Keyword(s):

Woody Plants ◽

Xylem Conduits

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Xylem conduits of a resurrection plant contain a unique lipid lining and refill following a distinct pattern after desiccation

New Phytologist ◽

10.1046/j.1469-8137.2000.00755.x ◽

2000 ◽

Vol 148 (2) ◽

pp. 239-255 ◽

Cited By ~ 33

Author(s):

H.-J. WAGNER ◽

H. SCHNEIDER ◽

S. MIMIETZ ◽

N. WISTUBA ◽

M. ROKITTA ◽

...

Keyword(s):

Distinct Pattern ◽

Resurrection Plant ◽

Xylem Conduits

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Wood Anatomy of Capparis Spinosa from an Ecological Perspective

IAWA Journal ◽

10.1163/22941932-90001567 ◽

1999 ◽

Vol 20 (4) ◽

pp. 419-429 ◽

Cited By ~ 17

Author(s):

G.K. Psaras ◽

I. Sofroniou

Keyword(s):

Wood Anatomy ◽

Adaptive Strategy ◽

Ecological Perspective ◽

Summer Drought ◽

Anatomical Features ◽

Vessel Elements ◽

Capparis Spinosa ◽

The Mediterranean ◽

Perforation Plates ◽

Xylem Conduits

Root and stern wood of the Mediterranean summergreen Capparis spinosa L. was studied. Wood anatomical features favour high hydraulic conductivity, which is necessary for maintaining the high midday stomatal conductance and rates of photosynthesis observed in this plant. Xylem conduits of both stern and root consist of wide and short vessel elements with simple perforation plates. Vessel grouping in the stern secures xylem safety against cavitations. The plant would be highly vulnerable to cavitations due to freezing conditions, although these are rare during the Mediterranean winter. Thus, the anatomical features of the plant, which does not seem to suffer from water stress though growing entirely during the Mediterranean summer drought, are compatible with its adaptive strategy. The significant amount of minerals found in the root vessels, and the abundant starch grains of the wood might be involved in a possible osmotic shifting of water in the xylem.

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