Temperature response of mesophyll conductance in cultivated and wild Oryza species with contrasting mesophyll cell wall thickness

Date

2011

Authors

Scafaro, Andrew P
von Caemmerer, Susanne
Evans, John
Atwell, Brian J

Journal Title

Journal ISSN

Volume Title

Publisher

Blackwell Publishing Ltd

Abstract

A critical component of photosynthetic capacity is the conductance of CO2 from intercellular airspaces to the sites of CO2 fixation in the stroma of chloroplasts, termed mesophyll conductance (gm). Leaf anatomy has been identified as an important determinant of gm. There are few studies of the temperature response of gm and none has examined the implications of leaf anatomy. Hence, we compared a cultivar of Oryza sativa with two wild Oryza relatives endemic to the hot northern savannah of Australia, namely Oryza meridionalis and Oryza australiensis. All three species had similar leaf anatomical properties, except that the wild relatives had significantly thicker mesophyll cell walls than O.sativa. Thicker mesophyll cell walls in the wild rice species are likely to have contributed to the reduction in gm, which was associated with a greater drawdown of CO2 into chloroplasts (Ci-Cc) compared with O.sativa. Mesophyll conductance increased at higher temperatures, whereas the rate of CO2 assimilation was relatively stable between 20 and 40°C. Consequently, Ci-Cc decreased for all three species as temperature increased.

Description

Keywords

Keywords: carbon; carbon dioxide; anatomy; carbon dioxide; cultivar; cultivation; photosynthesis; rice; stomatal conductance; temperature effect; wild population; agriculture; analysis of variance; article; cell wall; chloroplast; cytology; evapotranspiration; meso Internal conductance; Oryza australiensis; Oryza meridionalis; Oryza sativa; Photosynthesis; Rice; Stomatal conductance; Temperature

Citation

Source

Plant Cell and Environment

Type

Journal article

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2037-12-31