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Mesophyll conductance in cotton bracts: Anatomically determined internal CO2 diffusion constraints on photosynthesis


Han, J and Lei, Z and Flexas, J and Zhang, Y and Carriqui, M and Zhang, W and Zhang, Y, Mesophyll conductance in cotton bracts: Anatomically determined internal CO2 diffusion constraints on photosynthesis, Journal of Experimental Botany, 69, (22) pp. 5433-5443. ISSN 0022-0957 (2018) [Refereed Article]

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Copyright Statement

The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

DOI: doi:10.1093/jxb/ery296


Mesophyll conductance (gm) has been shown to affect photosynthetic capacity and thus the estimates of terrestrial carbon balance. While there have been some attempts to model gm at the leaf and larger scales, the potential contribution of gm to the photosynthesis of non-leaf green organs has not been studied. Here, we investigated the influence of gm on photosynthesis of cotton bracts and how it in turn is influenced by anatomical structures, by comparing leaf palisade and spongy mesophyll with bract tissue. Our results showed that photosynthetic capacity in bracts is much lower than in leaves, and that gm is a limiting factor for bract photosynthesis to a similar extent to stomatal conductance. Bract and the spongy tissue of leaves have lower mesophyll conductance than leaf palisade tissue due to the greater volume fraction of intercellular air spaces, smaller chloroplasts, lower surface area of mesophyll cells and chloroplasts exposed to leaf intercellular air spaces and, perhaps, lower membrane permeability. Comparing bracts with leaf spongy tissue, although bracts have a larger cell wall thickness, they have a similar gm estimated from anatomical characteristics, likely due to the cumulative compensatory effects of subtle differences in each subcellular component, especially chloroplast traits. These results provide the first evidence for anatomical constraints on gm and photosynthesis in non-leaf green organs.

Item Details

Item Type:Refereed Article
Keywords:anatomical structures, CO2 diffusion, cotton bracts, mesophyll conductance, non-leaf green organs, stomatal conductance
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Industrial crops
Objective Field:Cotton
UTAS Author:Carriqui, M (Mr Marc Carriqui Alcover)
ID Code:134468
Year Published:2018
Web of Science® Times Cited:19
Deposited By:Plant Science
Deposited On:2019-08-14
Last Modified:2019-09-18
Downloads:16 View Download Statistics

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