Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii
Abstract While the role of TOR kinase in the chloroplast biogenesis and transcriptional regulation of photosynthesis is well documented in Arabidopsis, the functional relevance of this metabolic sensor kinase in chloroplast–mitochondria cross talk is unknown. Using Chlamydomonas reinhardtii as the m...
Main Authors: | , |
---|---|
Format: | Article |
Language: | English |
Published: |
Wiley
2019-11-01
|
Series: | Plant Direct |
Subjects: | |
Online Access: | https://doi.org/10.1002/pld3.184 |
id |
doaj-d18f3ab1af2c464687a317d188cf7b59 |
---|---|
record_format |
Article |
spelling |
doaj-d18f3ab1af2c464687a317d188cf7b592021-05-02T05:03:11ZengWileyPlant Direct2475-44552019-11-01311n/an/a10.1002/pld3.184Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtiiShivani Upadhyaya0Basuthkar Jagadeeshwar Rao1Department of Biological Sciences Tata Institute of Fundamental Research (TIFR) Mumbai IndiaIndian Institute of Science Education and Research (IISER) Tirupati Transit Campus: Sree Rama Engineering College Tirupati IndiaAbstract While the role of TOR kinase in the chloroplast biogenesis and transcriptional regulation of photosynthesis is well documented in Arabidopsis, the functional relevance of this metabolic sensor kinase in chloroplast–mitochondria cross talk is unknown. Using Chlamydomonas reinhardtii as the model system, we demonstrate the role of TOR kinase in the regulation of chloroplast and mitochondrial functions: We show that TOR kinase inhibition impairs the maintenance of high ETR associated with PSII and low NPQ and inhibits efficient state transitions between PSII and PSI. While compromised photosynthetic functions are observed in TOR kinase inhibited cells, same conditions lead to augmentation in mitochondrial basal respiration rate by twofold and concomitantly a rise in ATP production. Interestingly, such upregulated mitochondrial functions in TOR‐inhibited cells are mediated by fragmented mitochondria via upregulating COXIIb and downregulating Hxk1 and AOX1 protein levels. We propose that TOR kinase may act as a sensor that counter‐regulates chloroplast versus mitochondrial functions in a normal C. reinhardtii cell.https://doi.org/10.1002/pld3.184alternative oxidaseautophagycytochrome oxidaselipid accumulationmitochondrial respirationphotosynthesis |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Shivani Upadhyaya Basuthkar Jagadeeshwar Rao |
spellingShingle |
Shivani Upadhyaya Basuthkar Jagadeeshwar Rao Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii Plant Direct alternative oxidase autophagy cytochrome oxidase lipid accumulation mitochondrial respiration photosynthesis |
author_facet |
Shivani Upadhyaya Basuthkar Jagadeeshwar Rao |
author_sort |
Shivani Upadhyaya |
title |
Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii |
title_short |
Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii |
title_full |
Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii |
title_fullStr |
Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii |
title_full_unstemmed |
Reciprocal regulation of photosynthesis and mitochondrial respiration by TOR kinase in Chlamydomonas reinhardtii |
title_sort |
reciprocal regulation of photosynthesis and mitochondrial respiration by tor kinase in chlamydomonas reinhardtii |
publisher |
Wiley |
series |
Plant Direct |
issn |
2475-4455 |
publishDate |
2019-11-01 |
description |
Abstract While the role of TOR kinase in the chloroplast biogenesis and transcriptional regulation of photosynthesis is well documented in Arabidopsis, the functional relevance of this metabolic sensor kinase in chloroplast–mitochondria cross talk is unknown. Using Chlamydomonas reinhardtii as the model system, we demonstrate the role of TOR kinase in the regulation of chloroplast and mitochondrial functions: We show that TOR kinase inhibition impairs the maintenance of high ETR associated with PSII and low NPQ and inhibits efficient state transitions between PSII and PSI. While compromised photosynthetic functions are observed in TOR kinase inhibited cells, same conditions lead to augmentation in mitochondrial basal respiration rate by twofold and concomitantly a rise in ATP production. Interestingly, such upregulated mitochondrial functions in TOR‐inhibited cells are mediated by fragmented mitochondria via upregulating COXIIb and downregulating Hxk1 and AOX1 protein levels. We propose that TOR kinase may act as a sensor that counter‐regulates chloroplast versus mitochondrial functions in a normal C. reinhardtii cell. |
topic |
alternative oxidase autophagy cytochrome oxidase lipid accumulation mitochondrial respiration photosynthesis |
url |
https://doi.org/10.1002/pld3.184 |
work_keys_str_mv |
AT shivaniupadhyaya reciprocalregulationofphotosynthesisandmitochondrialrespirationbytorkinaseinchlamydomonasreinhardtii AT basuthkarjagadeeshwarrao reciprocalregulationofphotosynthesisandmitochondrialrespirationbytorkinaseinchlamydomonasreinhardtii |
_version_ |
1721495136382222336 |