Functional variation in phyllogen, a phyllody‐inducing phytoplasma effector family, attributable to a single amino acid polymorphism. (19th August 2020)

• Record Type: Journal Article
• Authors: Iwabuchi, Nozomu; Kitazawa, Yugo; Maejima, Kensaku; Koinuma, Hiroaki; Miyazaki, Akio; Matsumoto, Ouki; Suzuki, Takumi; Nijo, Takamichi; Oshima, Kenro; Namba, Shigetou; Yamaji, Yasuyuki
• Is Part Of: Molecular plant pathology. Volume 21:Number 10(2020)
• Page Start: 1322
• Page End: 1336
• Publication Date: 2020-08-19
• Subjects: horizontal gene transfer -- MADS domain transcription factors -- natural variation -- phyllody -- phyllogen -- phytoplasma -- α‐helix; Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/mpp.12981
• Languages: English
• ISSNs: 1464-6722

Abstract

Abstract: Flower malformation represented by phyllody is a common symptom of phytoplasma infection induced by a novel family of phytoplasma effectors called phyllogens. Despite the accumulation of functional and structural phyllogen information, the molecular mechanisms of phyllody have not yet been integrated with their evolutionary aspects due to the limited data on their homologs across diverse phytoplasma lineages. Here, we developed a novel universal PCR‐based approach to identify 25 phytoplasma phyllogens related to nine " Candidatus Phytoplasma" species, including four species whose phyllogens have not yet been identified. Phylogenetic analyses showed that the phyllogen family consists of four groups (phyl‐A, ‐B, ‐C, and ‐D) and that the evolutionary relationships of phyllogens were significantly distinct from those of phytoplasmas, suggesting that phyllogens were transferred horizontally among phytoplasma strains and species. Although phyllogens belonging to the phyl‐A, ‐C, and ‐D groups induced phyllody, the phyl‐B group lacked the ability to induce phyllody. Comparative functional analyses of phyllogens revealed that a single amino acid polymorphism in phyl‐B group phyllogens prevented interactions between phyllogens and A‐ and E‐class MADS domain transcription factors (MTFs), resulting in the inability to degrade several MTFs and induce phyllody. Our finding of natural variation in the function of phytoplasma effectors provides new insights into molecular mechanisms underlying the aetiology of phytoplasma diseases. Abstract : Comparison of phyllogen, a phyllody‐inducing effector family, revealed its molecular evolution and functional variation attributed to a single amino acid polymorphism governing the phyllody symptoms of phytoplasma infection.