The 'Candidatus Phytoplasma mali' effector protein SAP11CaPm interacts with MdTCP16, a class II CYC/TB1 transcription factor that is highly expressed during phytoplasma infection

Cecilia Mittelberger; Bettina Hause; Katrin Janik

doi:10.1371/journal.pone.0272467

The 'Candidatus Phytoplasma mali' effector protein SAP11CaPm interacts with MdTCP16, a class II CYC/TB1 transcription factor that is highly expressed during phytoplasma infection

PLoS One. 2022 Dec 15;17(12):e0272467. doi: 10.1371/journal.pone.0272467. eCollection 2022.

Authors

Cecilia Mittelberger¹, Bettina Hause², Katrin Janik¹

Affiliations

¹ Molecular Biology and Microbiology, Group of Functional Genomics, Research Centre Laimburg, Pfatten (Vadena), South Tyrol, Italy.
² Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Halle, Saxony-Anhalt, Germany.

Abstract

'Candidatus Phytoplasma mali', is a bacterial pathogen associated with the so-called apple proliferation disease in Malus × domestica. The pathogen manipulates its host with a set of effector proteins, among them SAP11CaPm, which shares similarity to SAP11AYWB from 'Candidatus Phytoplasma asteris'. SAP11AYWB interacts and destabilizes the class II CIN transcription factors of Arabidopsis thaliana, namely AtTCP4 and AtTCP13 as well as the class II CYC/TB1 transcription factor AtTCP18, also known as BRANCHED1 being an important factor for shoot branching. It has been shown that SAP11CaPm interacts with the Malus × domestica orthologues of AtTCP4 (MdTCP25) and AtTCP13 (MdTCP24), but an interaction with MdTCP16, the orthologue of AtTCP18, has never been proven. The aim of this study was to investigate this potential interaction and close a knowledge gap regarding the function of SAP11CaPm. A Yeast two-hybrid test and Bimolecular Fluorescence Complementation in planta revealed that SAP11CaPm interacts with MdTCP16. MdTCP16 is known to play a role in the control of the seasonal growth of perennial plants and an increase of MdTCP16 gene expression has been detected in apple leaves in autumn. In addition to this, MdTCP16 is highly expressed during phytoplasma infection. Binding of MdTCP16 by SAP11CaPm might lead to the induction of shoot proliferation and early bud break, both of which are characteristic symptoms of apple proliferation disease.

Copyright: © 2022 Mittelberger et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arabidopsis* / genetics
Arabidopsis* / metabolism
Mali
Malus* / genetics
Phytoplasma Disease
Phytoplasma* / genetics
Plant Diseases / microbiology
Transcription Factors / genetics
Transcription Factors / metabolism

Substances

Transcription Factors

Grants and funding

The work of CM and KJ was co-funded by the Autonomous Province of Bozen/Bolzano (Italy, https://www.provinz.bz.it) and the South Tyrolean Apple Consortium (Italy, https://www.apfelwelt.it). The study was realized within the APPLIII and APPLIV project belonging to the Framework agreement in the field of invasive species in fruit growing and major pathologies (PROT. VZL_BZ 09.05.2018 0002552). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.