Tolerant mechanisms to O deficiency under submergence conditions in plants.

Wetland plants can tolerate long-term strict hypoxia and anoxic conditions and the subsequent re-oxidative stress compared to terrestrial plants. During O deficiency, both wetland and terrestrial plants use NAD(P) and ATP that are produced during ethanol fermentation, sucrose degradation, and major amino acid metabolisms. The oxidation of NADH by non-phosphorylating pathways in the mitochondrial respiratory chain is common in both terrestrial and wetland plants.

Root respiratory costs of ion uptake, root growth, and root maintenance in wetland plants: efficiency and strategy of O2 use for adaptation to hypoxia.

Oxygen use in roots is an important aspect of wetland plant ecophysiology, and it depends on the respiratory costs of three major processes: ion uptake, root growth, and root maintenance. However, O2 allocation in wetland plants has received little attention. This study aimed to determine the O2 allocation and specific respiratory cost of each process under hypoxic conditions, to better understand the strategy and efficiency of O2 use in wetland plants.

Functional linkage between N acquisition strategies and aeration capacities of hydrophytes for efficient oxygen consumption in roots.

We evaluated the specific strategies of hydrophytes for root O(2) consumption in relation to N acquisition and investigated whether the strategies varied depending on the aeration capacity. Aeration capacity of roots is an important factor for determining hypoxia tolerance in plants. However, some hydrophytes possessing quite different aeration capacities often co-occur in wetlands, suggesting that root O(2) consumption also strongly affects hypoxia tolerance.

Ecophysiological mechanisms characterising fen and bog species: focus on variations in nitrogen uptake traits under different soil-water pH.

Although the productivity and nitrogen (N)-use traits of mire plants differ dramatically between fens and bogs, soil N richness does not necessarily differ, whereas the soil-water pH is distinctly lower in bogs than in fens. The ecophysiological mechanisms underlying these relations are unclear. To assess the relative availability of N forms in relation to soil-water pH, we focused on the net N uptake rate per unit root weight (NNUR), glutamine synthetase activity and nitrate reductase activity, and performed reciprocal transplant experiments with the seedlings of fen (Carex lyngbyei) and bog (C.