Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2

Acclimation to variable CO2 was studied in floating leaves of the freshwater monocot Ottelia cordata grown in either low or high CO2. The most striking anatomical variations responding to high CO2 included the enlarged upper epidermal cells and the decreased area of epidermal chloroplasts. Stomata t...

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Main Authors: Wenmin Huang, Shijuan Han, Zhenfei Xing, Wei Li
Format: Article
Language:English
Published: Frontiers Media S.A. 2020-08-01
Series:Frontiers in Plant Science
Subjects:
C4
Online Access:https://www.frontiersin.org/article/10.3389/fpls.2020.01261/full
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spelling doaj-138a9a4b029c4c90a4c268bb0fc474102020-11-25T03:37:54ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2020-08-011110.3389/fpls.2020.01261558999Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2Wenmin Huang0Wenmin Huang1Shijuan Han2Shijuan Han3Zhenfei Xing4Wei Li5Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, ChinaAix Marseille Univ CNRS, BIP UMR 7281, IMM, FR 3479, Marseille, FranceKey Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaInstitute of Hydrobiology, Chinese Academy of Sciences, Wuhan, ChinaKey Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, ChinaAcclimation to variable CO2 was studied in floating leaves of the freshwater monocot Ottelia cordata grown in either low or high CO2. The most striking anatomical variations responding to high CO2 included the enlarged upper epidermal cells and the decreased area of epidermal chloroplasts. Stomata that distributed on the upper surface, and the stomatic chamber area, showed no significant response to high CO2. pH-drift experiments indicated that floating leaves of O. cordata were able to use bicarbonate regardless of CO2 concentrations. Photosynthetic enzyme activities and patterns of organic acids fluctuation confirmed that floating leaves of O. cordata can operate CAM only at low CO2, and perform C4-like metabolism at both high and low CO2. Overall, the present results imply that the floating leaves of O. cordata does not just rely on the atmospheric CO2 for its inorganic carbon, but is also dependent on CO2 and bicarbonate in the water. By showing these effects of CO2 variation, we highlight the need for further experimental studies on the regulatory mechanisms in O. cordata floating leaves, that prevent futile cycling among the three CO2 concentrating mechanisms (bicarbonate use, C4, and CAM metabolism) and the strategy for exploiting atmospheric CO2, as well as studies on the detailed biochemical pathway for C4 and CAM metabolism in this species.https://www.frontiersin.org/article/10.3389/fpls.2020.01261/fullCO2 availabilityC4crassulacean acid metabolismbicarbonate useCO2 concentrating mechanismsorganic acids
collection DOAJ
language English
format Article
sources DOAJ
author Wenmin Huang
Wenmin Huang
Shijuan Han
Shijuan Han
Zhenfei Xing
Wei Li
spellingShingle Wenmin Huang
Wenmin Huang
Shijuan Han
Shijuan Han
Zhenfei Xing
Wei Li
Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
Frontiers in Plant Science
CO2 availability
C4
crassulacean acid metabolism
bicarbonate use
CO2 concentrating mechanisms
organic acids
author_facet Wenmin Huang
Wenmin Huang
Shijuan Han
Shijuan Han
Zhenfei Xing
Wei Li
author_sort Wenmin Huang
title Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
title_short Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
title_full Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
title_fullStr Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
title_full_unstemmed Responses of Leaf Anatomy and CO2 Concentrating Mechanisms of the Aquatic Plant Ottelia cordata to Variable CO2
title_sort responses of leaf anatomy and co2 concentrating mechanisms of the aquatic plant ottelia cordata to variable co2
publisher Frontiers Media S.A.
series Frontiers in Plant Science
issn 1664-462X
publishDate 2020-08-01
description Acclimation to variable CO2 was studied in floating leaves of the freshwater monocot Ottelia cordata grown in either low or high CO2. The most striking anatomical variations responding to high CO2 included the enlarged upper epidermal cells and the decreased area of epidermal chloroplasts. Stomata that distributed on the upper surface, and the stomatic chamber area, showed no significant response to high CO2. pH-drift experiments indicated that floating leaves of O. cordata were able to use bicarbonate regardless of CO2 concentrations. Photosynthetic enzyme activities and patterns of organic acids fluctuation confirmed that floating leaves of O. cordata can operate CAM only at low CO2, and perform C4-like metabolism at both high and low CO2. Overall, the present results imply that the floating leaves of O. cordata does not just rely on the atmospheric CO2 for its inorganic carbon, but is also dependent on CO2 and bicarbonate in the water. By showing these effects of CO2 variation, we highlight the need for further experimental studies on the regulatory mechanisms in O. cordata floating leaves, that prevent futile cycling among the three CO2 concentrating mechanisms (bicarbonate use, C4, and CAM metabolism) and the strategy for exploiting atmospheric CO2, as well as studies on the detailed biochemical pathway for C4 and CAM metabolism in this species.
topic CO2 availability
C4
crassulacean acid metabolism
bicarbonate use
CO2 concentrating mechanisms
organic acids
url https://www.frontiersin.org/article/10.3389/fpls.2020.01261/full
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