View in EDS

Chloroplast NADH dehydrogenase‐like complex‐mediated cyclic electron flow is the main electron transport route in C4 bundle sheath cells.

Saved in:
Bibliographic Details
Title: Chloroplast NADH dehydrogenase‐like complex‐mediated cyclic electron flow is the main electron transport route in C4 bundle sheath cells.
Authors: Ermakova, Maria1,2 (AUTHOR) maria.ermakova@monash.edu, Woodford, Russell1,2 (AUTHOR), Fitzpatrick, Duncan1 (AUTHOR), Nix, Samuel J.1 (AUTHOR), Zwahlen, Soraya M.1,3 (AUTHOR), Farquhar, Graham D.1 (AUTHOR), von Caemmerer, Susanne1 (AUTHOR), Furbank, Robert T.1 (AUTHOR)
Source: New Phytologist. Sep2024, Vol. 243 Issue 6, p2187-2200. 14p.
Subjects: Electron transport, Carbon 4 photosynthesis, Photosystems, Reverse genetics, Plant growth
Abstract: Summary: The superior productivity of C4 plants is achieved via a metabolic C4 cycle which acts as a CO2 pump across mesophyll and bundle sheath (BS) cells and requires an additional input of energy in the form of ATP. The importance of chloroplast NADH dehydrogenase‐like complex (NDH) operating cyclic electron flow (CEF) around Photosystem I (PSI) for C4 photosynthesis has been shown in reverse genetics studies but the contribution of CEF and NDH to cell‐level electron fluxes remained unknown.We have created gene‐edited Setaria viridis with null ndhO alleles lacking functional NDH and developed methods for quantification of electron flow through NDH in BS and mesophyll cells.We show that CEF accounts for 84% of electrons reducing PSI in BS cells and most of those electrons are delivered through NDH while the contribution of the complex to electron transport in mesophyll cells is minimal. A decreased leaf CO2 assimilation rate and growth of plants lacking NDH cannot be rescued by supplying additional CO2.Our results indicate that NDH‐mediated CEF is the primary electron transport route in BS chloroplasts highlighting the essential role of NDH in generating ATP required for CO2 fixation by the C3 cycle in BS cells. [ABSTRACT FROM AUTHOR]
Copyright of New Phytologist is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Summary: The superior productivity of C4 plants is achieved via a metabolic C4 cycle which acts as a CO2 pump across mesophyll and bundle sheath (BS) cells and requires an additional input of energy in the form of ATP. The importance of chloroplast NADH dehydrogenase‐like complex (NDH) operating cyclic electron flow (CEF) around Photosystem I (PSI) for C4 photosynthesis has been shown in reverse genetics studies but the contribution of CEF and NDH to cell‐level electron fluxes remained unknown.We have created gene‐edited Setaria viridis with null ndhO alleles lacking functional NDH and developed methods for quantification of electron flow through NDH in BS and mesophyll cells.We show that CEF accounts for 84% of electrons reducing PSI in BS cells and most of those electrons are delivered through NDH while the contribution of the complex to electron transport in mesophyll cells is minimal. A decreased leaf CO2 assimilation rate and growth of plants lacking NDH cannot be rescued by supplying additional CO2.Our results indicate that NDH‐mediated CEF is the primary electron transport route in BS chloroplasts highlighting the essential role of NDH in generating ATP required for CO2 fixation by the C3 cycle in BS cells. [ABSTRACT FROM AUTHOR]
ISSN:0028646X
DOI:10.1111/nph.19982