Water transport and gas exchange in the non-vascular plant Dendroligotrichum dendroides (Brid. ex Hedw.)Broth. (Polytrichaceae, Bryophyta)

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

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OPTIMIZATION OF THE PENMAN-MONTEITH TRANSPIRATION RATE BY GAS EXCHANGE AND STEM WATER TRANSPORT MEASUREMENTS IN GRAPEVINES

Acta Horticulturae ◽

10.17660/actahortic.1999.493.29 ◽

1999 ◽

pp. 293-300 ◽

Cited By ~ 1

Author(s):

C. Lovisolo ◽

S. Ferraris ◽

A. Armando ◽

A. Schubert

Keyword(s):

Gas Exchange ◽

Water Transport ◽

Transpiration Rate ◽

Transport Measurements ◽

Stem Water

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Relation of water transport to leaf gas exchange properties in three mangrove species

Trees ◽

10.1007/s004680050011 ◽

2000 ◽

Vol 14 (5) ◽

pp. 0258-0262 ◽

Cited By ~ 47

Author(s):

M. A. Sobrado

Keyword(s):

Gas Exchange ◽

Water Transport ◽

Leaf Gas Exchange ◽

Mangrove Species ◽

Exchange Properties

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Water transport from stem to stomata: the coordination of hydraulic and gas exchange traits across 33 subtropical woody species

Tree Physiology ◽

10.1093/treephys/tpz076 ◽

2019 ◽

Vol 39 (10) ◽

pp. 1665-1674 ◽

Cited By ~ 3

Author(s):

Xiaorong Liu ◽

Hui Liu ◽

Sean M Gleason ◽

Guillermo Goldstein ◽

Shidan Zhu ◽

...

Keyword(s):

Stomatal Conductance ◽

Gas Exchange ◽

Water Transport ◽

Explanatory Power ◽

Woody Species ◽

Hydraulic Conductance ◽

Co2 Assimilation ◽

Leaf Hydraulic Conductance ◽

Net Co2 Assimilation ◽

Leaf Tissues

Abstract Coordination between sapwood-specific hydraulic conductivity (Ks) and stomatal conductance (gs) has been identified in previous studies; however, coordination between leaf hydraulic conductance (Kleaf) and gs, as well as between Kleaf and Ks is not always consistent. This suggests that there is a need to improve our understanding of the coordination among hydraulic and gas exchange traits. In this study, hydraulic traits (e.g., Ks and Kleaf) and gas exchange traits, including gs, transpiration (E) and net CO2 assimilation (Aarea), were measured across 33 co-occurring subtropical woody species. Kleaf was divided into two components: leaf hydraulic conductance inside the xylem (Kleaf-x) and outside the xylem (Kleaf-ox). We found that both Kleaf-x and Kleaf-ox were coordinated with gs and E, but the correlations between Kleaf-ox and gs (or E) were substantially weaker, and that Ks was coordinated with Kleaf-x, but not with Kleaf-ox. In addition, we found that Ks, Kleaf-x and Kleaf-ox together explained 63% of the variation in gs and 42% of the variation in Aarea across species, with Ks contributing the largest proportion of explanatory power, whereas Kleaf-ox contributed the least explanatory power. Our results demonstrate that the coordination between leaf water transport and gas exchange, as well as the hydraulic linkage between leaf and stem, were weakened by Kleaf-ox. This highlights the possibility that water transport efficiencies of stem and leaf xylem, rather than that of leaf tissues outside the xylem, are important determinants of stomatal conductance and photosynthetic capacity across species.

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