Changes of photosynthetic traits in beech saplings (Fagus sylvatica) under severe drought stress and during recovery

Gallé, Alexander; Feller, Urs (2007). Changes of photosynthetic traits in beech saplings (Fagus sylvatica) under severe drought stress and during recovery. Physiologia Plantarum, 131(3), pp. 412-421. Oxford: Blackwell 10.1111/j.1399-3054.2007.00972.x

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In the context of an increased risk of extreme drought events across Europe during the next decades, the capacity of trees to recover and survive drought periods awaits further attention. In summer 2005, 4-year-old beech (Fagus sylvatica L.) saplings were watered regularly or were kept for 4 weeks without irrigation in the field and then re-watered again. Changes of plant water status, leaf gas exchange and Chl a fluorescence parameters, as well as alterations in leaf pigment composition were followed. During the drought period, stomatal conductance (g(s)) and net photosynthesis (P(n)) decreased in parallel with increased water deficit. After 14 days without irrigation, stomata remained closed and P(n) was almost completely inhibited. Reversible downregulation of PSII photochemistry [the maximum quantum efficiency of PSII (F(v)/F(m))], enhanced thermal dissipation of excess excitation energy and an increased ratio of xanthophyll cycle pigments to chlorophylls (because of a loss of chlorophylls) contributed to an enhanced photo-protection in severely stressed plants. Leaf water potential was restored immediately after re-watering, while g(s), P(n) and F(v)/F(m) recovered only partially during the initial phase, even when high external CO(2) concentrations were applied during the measurements, indicating lasting non-stomatal limitations. Thereafter, P(n) recovered completely within 4 weeks, meanwhile g(s) remained permanently lower in stressed than in control plants, leading to an increased 'intrinsic water use efficiency' (P(n)/g(s)). In conclusion, although severe drought stress adversely affected photosynthetic performance of F. sylvatica (a rather drought-sensitive species), P(n) was completely restored after re-watering, presumably because of physiological and morphological adjustments (e.g. stomatal occlusions).

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Plant nutrition [discontinued]
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Gallé, Alexander, Feller-Kaiser, Urs

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0031-9317

Publisher:

Blackwell

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

04 Oct 2013 14:58

Last Modified:

05 Dec 2022 14:17

Publisher DOI:

10.1111/j.1399-3054.2007.00972.x

PubMed ID:

18251880

Web of Science ID:

000249827100006

BORIS DOI:

10.7892/boris.24721

URI:

https://boris.unibe.ch/id/eprint/24721 (FactScience: 52863)

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