Abstract
Analogues of vertebrate natriuretic peptides (NPs) present in plants, termed plant natriuretic peptides (PNPs), comprise a novel class of hormones that systemically affect salt and water balance and responses to plant pathogens. Several lines of evidence indicate that Arabidopsis thaliana PNP (AtPNP-A) affects cellular redox homeostasis, which is also typical for the signaling of its vertebrate analogues, but the molecular mechanism(s) of this effect remains elusive. Here we report identification of catalase 2 (CAT2), an antioxidant enzyme, as an interactor of AtPNP-A. The full-length AtPNP-A recombinant protein and the biologically active fragment of AtPNP-A bind specifically to CAT2 in surface plasmon resonance (SPR) analyses, while a biologically inactive scrambled peptide does not. In vivo bimolecular fluorescence complementation (BiFC) showed that CAT2 interacts with AtPNP-A in chloroplasts. Furthermore, CAT2 activity is lower in homozygous atpnp-a knockdown compared with wild type plants, and atpnp-a knockdown plants phenocopy CAT2-deficient plants in their sensitivity to elevated H2O2, which is consistent with a direct modulatory effect of the PNP on the activity of CAT2 and hence H2O2 homeostasis. Our work underlines the critical role of AtPNP-A in modulating the activity of CAT2 and highlights a mechanism of fine-tuning plant responses to adverse conditions by PNPs.
Original language | English (US) |
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Journal | Scientific reports |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Nov 13 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-11-16Acknowledgements: Funding was provided by Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology. Ilona Turek was supported by a King Abdullah University of Science and Technology doctoral scholarship. Part of this work was supported by the Australian Research Council [Discovery Project funding scheme (DP0557561, DP0878194)], Australian Postgraduate Award to YHW, and also by La Trobe University. We thank the Salk Institute Genomic Analysis Laboratory for providing the sequence-indexed Arabidopsis T-DNA insertion mutants and Dr Peter Lock (La Trobe University LIMS BioImaging Facility) for assistance with imaging.