skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Phosphorylation of Phospho enolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO 2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi

Abstract

Phosphoenolpyruvate carboxylase (PPC; EC 4.1.1.31) catalyzes primary nocturnal CO 2 fixation in Crassulacean acid metabolism (CAM) species. CAM PPC is regulated posttranslationally by a circadian clock-controlled protein kinase called phosphoe nolpyruvate carboxylase kinase (PPCK). PPCK phosphorylates PPC during the dark period, reducing its sensitivity to feedback inhibition by malate and thus enhancing nocturnal CO 2 fixation to stored malate. Here, we report the generation and characterization of transgenic RNAi lines of the obligate CAM species Kalanchoë fedtschenkoi with reduced levels of KfPPCK1 transcripts. Plants with reduced or no detectable dark phosphorylation of PPC displayed up to a 66% reduction in total dark period CO 2 fixation. These perturbations paralleled reduced malate accumulation at dawn and decreased nocturnal starch turnover. Loss of oscillations in the transcript abundance of KfPPCK1 was accompanied by a loss of oscillations in the transcript abundance of many core circadian clock genes, suggesting that perturbing the only known link between CAM and the circadian clock feeds back to perturb the central circadian clock itself. This work shows that clock control of KfPPCK1 prolongs the activity of PPC throughout the dark period in K. fedtschenkoi, optimizing CAM-associated dark CO 2 fixation, malate accumulation, CAM productivity, and core circadianmore » clock robustness.« less

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Univ. of Liverpool, Liverpool (United Kingdom)
Publication Date:
Research Org.:
Univ. of Nevada, Reno, NV (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1529433
Alternate Identifier(s):
OSTI ID: 1546706
Grant/Contract Number:  
SC0008834
Resource Type:
Published Article
Journal Name:
Plant Cell
Additional Journal Information:
Journal Volume: 29; Journal Issue: 10; Journal ID: ISSN 1040-4651
Publisher:
American Society of Plant Biologists
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Boxall, Susanna F., Dever, Louisa V., Kneřová, Jana, Gould, Peter D., and Hartwell, James. Phosphorylation of Phosphoenolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi. United States: N. p., 2017. Web. doi:10.1105/tpc.17.00301.
Boxall, Susanna F., Dever, Louisa V., Kneřová, Jana, Gould, Peter D., & Hartwell, James. Phosphorylation of Phosphoenolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi. United States. doi:10.1105/tpc.17.00301.
Boxall, Susanna F., Dever, Louisa V., Kneřová, Jana, Gould, Peter D., and Hartwell, James. Fri . "Phosphorylation of Phosphoenolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi". United States. doi:10.1105/tpc.17.00301.
@article{osti_1529433,
title = {Phosphorylation of Phosphoenolpyruvate Carboxylase Is Essential for Maximal and Sustained Dark CO2 Fixation and Core Circadian Clock Operation in the Obligate Crassulacean Acid Metabolism Species Kalanchoë fedtschenkoi},
author = {Boxall, Susanna F. and Dever, Louisa V. and Kneřová, Jana and Gould, Peter D. and Hartwell, James},
abstractNote = {Phosphoenolpyruvate carboxylase (PPC; EC 4.1.1.31) catalyzes primary nocturnal CO2 fixation in Crassulacean acid metabolism (CAM) species. CAM PPC is regulated posttranslationally by a circadian clock-controlled protein kinase called phosphoenolpyruvate carboxylase kinase (PPCK). PPCK phosphorylates PPC during the dark period, reducing its sensitivity to feedback inhibition by malate and thus enhancing nocturnal CO2 fixation to stored malate. Here, we report the generation and characterization of transgenic RNAi lines of the obligate CAM species Kalanchoë fedtschenkoi with reduced levels of KfPPCK1 transcripts. Plants with reduced or no detectable dark phosphorylation of PPC displayed up to a 66% reduction in total dark period CO2 fixation. These perturbations paralleled reduced malate accumulation at dawn and decreased nocturnal starch turnover. Loss of oscillations in the transcript abundance of KfPPCK1 was accompanied by a loss of oscillations in the transcript abundance of many core circadian clock genes, suggesting that perturbing the only known link between CAM and the circadian clock feeds back to perturb the central circadian clock itself. This work shows that clock control of KfPPCK1 prolongs the activity of PPC throughout the dark period in K. fedtschenkoi, optimizing CAM-associated dark CO2 fixation, malate accumulation, CAM productivity, and core circadian clock robustness.},
doi = {10.1105/tpc.17.00301},
journal = {Plant Cell},
number = 10,
volume = 29,
place = {United States},
year = {2017},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1105/tpc.17.00301

Citation Metrics:
Cited by: 14 works
Citation information provided by
Web of Science

Save / Share:

Works referencing / citing this record: