Open AccessPhytoplasma effector SWP1 induces witches’ broom symptom by destabilizing the TCP transcription factor BRANCHED1
Author(s) -
Wang Nan,
Yang Haizhen,
Yin Zhiyuan,
Liu Wenting,
Sun Liying,
Wu Yunfeng
Publication year - 2018
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12733
Subject(s) - nicotiana benthamiana , effector , broom , biology , phytoplasma , arabidopsis thaliana , mutant , microbiology and biotechnology , genetics , gene , genotype , ecology , restriction fragment length polymorphism
Summary Phytoplasmas are insect‐transmitted phytopathogenic bacteria, which secrete effector proteins that are often responsible for altering the plant morphology and behaviours of their vectors. Phytoplasma multifunctional effector proteins TENGU and SAP11 induce typical witches’ broom symptoms, but their mode of action remains unknown. Previously, we have identified a SAP11‐like effector from wheat blue dwarf phytoplasma, SWP1, which induces witches’ broom symptoms in Nicotiana benthamiana . In this study, we observed that SWP1 ‐expressing transgenic Arabidopsis thaliana plants showed typical witches’ broom symptoms. On overexpression of SWP1 truncation mutants in N. benthamiana , we identified that the coiled‐coil domain and nuclear localization were responsible for the induction of witches’ broom symptoms. In addition, using yeast two‐hybrid and bimolecular fluorescence complementation assays, we demonstrated that SWP1 interacts with A. thaliana transcription factor TCP18 (BRC1), the key negative regulator of branching signals in various plant species. Moreover, in planta co‐expression analysis showed that SWP1 promotes the degradation of BRC1 via a proteasome system. These findings suggest that the phytoplasma effector SWP1 induces witches’ broom symptoms through targeting of BRC1 and promoting its degradation.