Photosynthesis and photoinhibition in two xerophytic shrubs during drought

Title:

Photosynthesis and photoinhibition in two xerophytic shrubs during drought

Creator:

Tezara, W., Marín, O., Rengifo, E., Martínez, D., and Herrera, A.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:79e844a2-a901-4a57-a4a4-551518b6f838
uuid:79e844a2-a901-4a57-a4a4-551518b6f838
issn:0300-3604
doi:10.1007/s11099-005-7045-5

Subject:

fluorescence, Ipomoea carnea, Jatropha gossypifolia, net photosynthetic rate, quantum yield, photosystem 2, stomatal conductance, water stress, and xerophytes

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Seasonal changes in water relations, net photosynthetic rate (PN), and fluorescence of chlorophyll (Chl) a of two perennial C3 deciduous shrubs, Ipomoea carnea and Jatropha gossypifolia, growing in a thorn scrub in Venezuela were studied in order to establish the possible occurrence of photoinhibition during dry season and determine whether changes in photochemical activity of photosystem 2 (PS2) may explain variations of PN in these species. Leaf water potential (ψ) decreased from -0.2 to -2.1 MPa during drought in both species. The PN decreased with ψ in I. carnea and J. gossypifolia by 64 and 74 %, respectively. Carboxylation efficiency (CE) decreased by more than 50 and 70 % in I. carnea and J. gossypifolia, respectively. In I. carnea, relative stomatal limitation (Ls) increased by 17 % and mesophyll limitation (Lm) by 65 % during drought, while in J. gossypifolia Ls decreased by 27 % and Lm increased by 51 %. Drought caused a reduction in quantum yield of PS2 (ϕPS2) in both species. Drought affected the capacity of energy dissipation of leaves, judging from the changes in the photochemical (qP) and non-photochemical quenching (NPQ) coefficients. Photoinhibition during drought in I. carnea and J. gossypifolia was evidenced in the field by a drop in the maximum quantum yield of PS2 (Fv/Fm) below 0.8 and also by non-coordinated changes in ϕPS2 and quantum yield of non-photochemical excitation quenching (Yn). Total soluble protein content on an area basis increased with ψ but the ribulose-1,5-bisphosphate carboxylase/oxygenase content remained unchanged. A reduction of total Chl content with drought was observed. Hence in the species studied photoinhibition occurred, which imposed an important limitation on carbon assimilation during drought. and W. Tezara ... [et al.].

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

37-45

Source:

Photosynthetica | 2005 Volume:43 | Number:1

Harvested from:

CDK

Metadata only:

false