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Growth and physiological responses of isohydric and anisohydric poplars to drought.

Attia Z, Domec JC, Oren R, Way DA, Moshelion M - J. Exp. Bot. (2015)

Bottom Line: Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress.Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI).Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.

No MeSH data available.


Related in: MedlinePlus

Conceptual model for behaviour of isohydric versus anisohydric plants by means of regulating (A) Ψleaf, (B) productivity, and (C) survival in response to increasing relative water stress, which accounts for changes in the SWCg and the period of time water stress was applied (this figure is available in colour at JXB online).
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Figure 6: Conceptual model for behaviour of isohydric versus anisohydric plants by means of regulating (A) Ψleaf, (B) productivity, and (C) survival in response to increasing relative water stress, which accounts for changes in the SWCg and the period of time water stress was applied (this figure is available in colour at JXB online).

Mentions: This study demonstrates that three genotypes of poplar, a key woody biomass species, have different strategies to cope with drought stress, with implications for their suitability for biomass production. The contrasting stomatal and leaf hydraulic behaviours between genotypes ranged from a rapidly responding isohydric behaviour (BS), which is hypothesized to increase survival under drought at the cost of low biomass production, to an anisohydric behaviour (SI and BSxSI) that is thought to allow carbon uptake and maintain high growth rates for a longer period during drought, but to expose the plant to greater risk of drought-induced mortality if the drought persists. Overall, the results indicated three strategies for how the closely related biomass genotypes deal with water stress: survival-isohydric, sensitive-anisohydric, and resilience-anisohydric (Fig. 6). By reducing hydraulic and stomatal conductance to maintain a constant Ψleaf, the isohydric poplars minimized the exposure of their leaves to water stress, but also decreased their ability to fix carbon for growth as the soil dried. By contrast, the anisohydric plants kept a high AN while Ψleaf declined, which should enable higher productivity in the anisohydric poplars, but also made them more vulnerable to damage from prolonged drought stress (Figs 2, 4, 5, 6). Given that recent work in 37 hybrid and pure species of poplar has shown that mean water potentials at which 50% of conductivity is lost range between −1.3 and −1.5MPa, with a large number of hybrids losing 50% of conductivity at water potentials >−1MPa (Fichot et al., 2015), the Ψstem values of near −0.9MPa shown here were likely sufficient to induce significant cavitation.


Growth and physiological responses of isohydric and anisohydric poplars to drought.

Attia Z, Domec JC, Oren R, Way DA, Moshelion M - J. Exp. Bot. (2015)

Conceptual model for behaviour of isohydric versus anisohydric plants by means of regulating (A) Ψleaf, (B) productivity, and (C) survival in response to increasing relative water stress, which accounts for changes in the SWCg and the period of time water stress was applied (this figure is available in colour at JXB online).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493787&req=5

Figure 6: Conceptual model for behaviour of isohydric versus anisohydric plants by means of regulating (A) Ψleaf, (B) productivity, and (C) survival in response to increasing relative water stress, which accounts for changes in the SWCg and the period of time water stress was applied (this figure is available in colour at JXB online).
Mentions: This study demonstrates that three genotypes of poplar, a key woody biomass species, have different strategies to cope with drought stress, with implications for their suitability for biomass production. The contrasting stomatal and leaf hydraulic behaviours between genotypes ranged from a rapidly responding isohydric behaviour (BS), which is hypothesized to increase survival under drought at the cost of low biomass production, to an anisohydric behaviour (SI and BSxSI) that is thought to allow carbon uptake and maintain high growth rates for a longer period during drought, but to expose the plant to greater risk of drought-induced mortality if the drought persists. Overall, the results indicated three strategies for how the closely related biomass genotypes deal with water stress: survival-isohydric, sensitive-anisohydric, and resilience-anisohydric (Fig. 6). By reducing hydraulic and stomatal conductance to maintain a constant Ψleaf, the isohydric poplars minimized the exposure of their leaves to water stress, but also decreased their ability to fix carbon for growth as the soil dried. By contrast, the anisohydric plants kept a high AN while Ψleaf declined, which should enable higher productivity in the anisohydric poplars, but also made them more vulnerable to damage from prolonged drought stress (Figs 2, 4, 5, 6). Given that recent work in 37 hybrid and pure species of poplar has shown that mean water potentials at which 50% of conductivity is lost range between −1.3 and −1.5MPa, with a large number of hybrids losing 50% of conductivity at water potentials >−1MPa (Fichot et al., 2015), the Ψstem values of near −0.9MPa shown here were likely sufficient to induce significant cavitation.

Bottom Line: Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress.Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI).Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.

No MeSH data available.


Related in: MedlinePlus