Boxall, Susanna 
ORCID: 0000-0002-8753-101X, Kadu, Nirja, Dever, Louisa ORCID: 0000-0001-7801-5622, Kneřová, Jana, Waller, Jade, Gould, Peter ORCID: 0000-0002-0709-1190 and Hartwell, James ORCID: 0000-0001-5000-223X
(2019)
Silencing<i>PHOSPHOENOLPYRUVATE CARBOXYLASE1</i>in the Obligate Crassulacean Acid Metabolism Species<i>Kalanchoë laxiflora</i>causes Reversion to C<sub>3</sub>-like Metabolism and Amplifies Rhythmicity in a Subset of Core Circadian Clock Genes.
BioRXiv Plant Biology.
684050-.
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Boxall_et_al_2019_bioRXiv_Plant_Biology_684050.full.pdf - Submitted version Download (37MB) | Preview |
Abstract
<h4>ABSTRACT</h4> Unlike C 3 plants, Crassulacean acid metabolism (CAM) plants fix CO 2 in the dark using phosphoenolpyruvate carboxylase (PPC; EC 4.1.1.31). PPC combines PEP with CO 2 (as HCO 3 − ), forming oxaloacetate that is rapidly converted to malate, leading to vacuolar malic acid accumulation that peaks phased to dawn. In the light period, malate decarboxylation concentrates CO 2 around RuBisCO for secondary fixation. CAM mutants lacking PPC have not been described. Here, RNAi was employed to silence CAM isogene PPC1 in Kalanchoë laxiflora . Line rPPC1-B lacked PPC1 transcripts, PPC activity, dark period CO 2 fixation, and nocturnal malate accumulation. Light period stomatal closure was also perturbed, and the plants displayed reduced but detectable dark period stomatal conductance, and arrhythmia of the CAM CO 2 fixation circadian rhythm under constant light and temperature (LL) free-running conditions. By contrast, the rhythm of delayed fluorescence was enhanced in plants lacking PPC1 . Furthermore, a subset of gene transcripts within the central circadian oscillator were up-regulated and oscillated robustly. The regulation guard cell genes involved controlling stomatal movements was also altered in rPPC1-B . This provided direct evidence that altered regulatory patterns of key guard cell signaling genes are linked with the characteristic inverse pattern of stomatal opening and closing during CAM.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Genetics, Sleep Research |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 28 Oct 2019 09:22 |
| Last Modified: | 15 Mar 2024 02:39 |
| DOI: | 10.1101/684050 |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3059532 |
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