The influence of soil temperature and water content on belowground hydraulic conductance and leaf gas exchange in mature trees of three boreal species

2020 ◽  
Vol 43 (3) ◽  
pp. 532-547 ◽  
Author(s):  
Anna Lintunen ◽  
Teemu Paljakka ◽  
Yann Salmon ◽  
Roderick Dewar ◽  
Anu Riikonen ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek

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.


Oecologia ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 356-362 ◽  
Author(s):  
T. Gollan ◽  
N. C. Turner ◽  
E. -D. Schulze

Oecologia ◽  
1984 ◽  
Vol 63 (3) ◽  
pp. 338-342 ◽  
Author(s):  
Neil C. Turner ◽  
E.-D. Schulze ◽  
T. Gollan

Botany ◽  
2014 ◽  
Vol 92 (7) ◽  
pp. 535-540 ◽  
Author(s):  
Ori Baber ◽  
Martijn Slot ◽  
Gerardo Celis ◽  
Kaoru Kitajima

A fundamental aspect of the carbon cycle is the exchange of carbon between plants and the atmosphere. It is, therefore, important to understand factors that affect differences in gas exchange and carbon balance within and among species. Concentrations of nonstructural carbohydrates are often used as a proxy for carbon balance. We determined diel patterns of leaf carbohydrate concentrations in relation to irradiance (sun vs. shade) in seedlings and mature trees of two sympatric oak species (Quercus virginiana Mill. and Quercus hemisphaerica Bartram ex Willd.). For seedlings, we also measured leaf gas exchange. Higher sun exposure significantly increased photosynthesis and carbohydrate concentrations in both species. Carbohydrate concentrations of seedling leaves showed strong diel fluctuations, whereas concentrations in mature tree leaves did not. This contrast might be attributed to faster carbohydrate export from leaves of mature trees. The difference in sink strength between seedlings and adults may be related to the decreasing ratio of leaf mass to plant mass with ontogeny, increasing the demand for carbohydrates per unit leaf mass. Seedlings and mature trees are clearly functionally different and care must be taken when extrapolating results from seedling experiments to mature trees.


2013 ◽  
Vol 57 (3) ◽  
pp. 531-539 ◽  
Author(s):  
A. Sellin ◽  
A. Niglas ◽  
E. Ounapuu ◽  
A. Karusion

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