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Mesophyll conductance in two cultivars of wheat grown in glacial to super-elevated CO2 concentrations.

Authors :
Jahan E
Thomson PC
Tissue DT
Source :
Journal of experimental botany [J Exp Bot] 2021 Oct 26; Vol. 72 (20), pp. 7191-7202.
Publication Year :
2021

Abstract

Mesophyll conductance (gm) is an important factor limiting photosynthesis. However, gm response to long-term growth in variable [CO2] is not well understood, particularly in crop plants. Here, we grew two cultivars of wheat (Halberd and Cranbrook), known to differ in gm under current environmental conditions, in four [CO2] treatments: glacial (206 μmol mol-1), pre-industrial (344 μmol mol-1), current ambient (489 μmol mol-1), and super-elevated (1085 μmol mol-1), and two water treatments (well-watered and moderate water limitation), to develop an evolutionary and future climate perspective on gm control of photosynthesis and water-use efficiency (WUE). In the two wheat genotypes, gm increased with rising [CO2] from glacial to ambient [CO2], but declined at super-elevated [CO2]. The responses of gm to different growth [CO2] also depend on water stress; however, the specific mechanism of gm response to [CO2] remains unclear. Although gm and gm/gsc (mesophyll conductance/stomatal conductance) were strongly associated with the variability of photosynthetic rates (A) and WUE, we found that plants with higher gm may increase A without increasing gsc, which increased WUE. These results may be useful to inform plant breeding programmes and cultivar selection for Australian wheat under future environmental conditions.<br /> (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Details

Language :
English
ISSN :
1460-2431
Volume :
72
Issue :
20
Database :
MEDLINE
Journal :
Journal of experimental botany
Publication Type :
Academic Journal
Accession number :
34232298
Full Text :
https://doi.org/10.1093/jxb/erab320