Identification and characterisation of suppressor mutants complementing a photorespiratory defect in the Arabidopsis mutant er-ant1
- More than ten years ago, ER-ANT1 was shown to act as an ATP/ADP antiporter and to exist in the endoplasmic reticulum (ER) of higher plants. Because structurally different transporters generally mediate energy provision to the ER, the physiological function of ER-ANT1 was not directly evident. Interestingly, mutant plants lacking ER-ANT1 exhibit a photorespiratory phenotype. Although many research efforts were undertaken, the possible connection between the transporter and photorespiration also remained elusive. Here, a forward genetic approach was used to decipher the role of ER-ANT1 in the plant context and its association to photorespiration. This strategy identified that additional absence of a putative HAD-type phosphatase partially restored the photorespiratory phenotype. Localisation studies revealed that the corresponding protein is targeted to the chloroplast. Moreover, biochemical analyses demonstrate that the HAD-type phosphatase is specific for pyridoxal phosphate. These observations, together with transcriptional and metabolic data of corresponding single (ER-ANT1) and double (ER-ANT1, phosphatase) loss-of-function mutant plants revealed an unexpected connection of ER-ANT1 to vitamin B6 metabolism. Finally, a scenario is proposed, which explains how ER-ANT1 may influence B6 vitamer phosphorylation, by this affects photorespiration and causes several other physiological alterations observed in the corresponding loss-of-function mutant plants.
Author: | Jacqueline Sabrina Altensell |
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URN: | urn:nbn:de:hbz:386-kluedo-58803 |
Advisor: | Ekkehard Neuhaus |
Document Type: | Doctoral Thesis |
Language of publication: | English |
Date of Publication (online): | 2020/02/03 |
Year of first Publication: | 2020 |
Publishing Institution: | Technische Universität Kaiserslautern |
Granting Institution: | Technische Universität Kaiserslautern |
Acceptance Date of the Thesis: | 2019/07/26 |
Date of the Publication (Server): | 2020/02/04 |
Page Number: | IV, 119 |
Faculties / Organisational entities: | Kaiserslautern - Fachbereich Biologie |
DDC-Cassification: | 5 Naturwissenschaften und Mathematik / 570 Biowissenschaften, Biologie |
Licence (German): | Creative Commons 4.0 - Namensnennung (CC BY 4.0) |