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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Molecular Plant Pathology Laboratory » Research » Publications at this Location » Publication #402506
Research Project: Omics-Based Approach to Detection, Identification, and Systematics of Plant Pathogenic Phytoplasmas and Spiroplasmas

Location: Molecular Plant Pathology Laboratory

Title: Phytoplasma infection alters polar lipid composition and triggers chloroplast autophagy in host plants

Author
item Inaba, Junichi
item KIM, BO MIN - Orise Fellow
item Zhao, Yan
item Wei, Wei

Submitted to: Phytopathogenic Mollicutes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2023
Publication Date: 5/23/2023
Citation: Inaba, J., Kim, B., Zhao, Y., Wei, W. 2023. Phytoplasma infection alters polar lipid composition and triggers chloroplast autophagy in host plants. Phytopathogenic Mollicutes. 13(1):3-4. https://doi.org/10.5958/2249-4677.2023.00002.6.
DOI: https://doi.org/10.5958/2249-4677.2023.00002.6

Interpretive Summary: Phytoplasmas are minute and unculturable bacteria that are responsible for various plant diseases. In the present study, ARS scientists in Beltsville, Maryland reported phytoplasma infection induced changes in polar lipid composition, which are important molecules involved in various plant functions. The levels of some types of polar lipids were decreased in the infected plants. These alterations in lipid composition may contribute to the development of yellowing symptoms and a reduction in photosynthesis efficiency. The study also found that the phytoplasma infection triggered the degradation of chloroplast proteins, which are important for photosynthesis, and activated a process called autophagy in the chloroplasts. Autophagy is a process by which cells break down and recycle their own components. These findings suggest that phytoplasma infection can significantly alter the normal functioning of plants and lead to disease symptoms. The study sheds light on the mechanisms of phytoplasma infection and could contribute to the development of new strategies for controlling plant diseases caused by phytoplasmas. The findings from this study will benefit researchers, students and university professors who are interested in plant-pathogens interactions.

Technical Abstract: Phytoplasmas are small, cell wall-less bacteria that infect a wide range of plant species. In this study, we investigated changes in the polar lipid composition of tomato plants infected with potato purple top (PPT) phytoplasma. The analysis revealed a decrease in the levels of Monogalactosyldiacylglycerol (MGDG), Phosphatidic acid (PA) and Phosphatidylglycerol (PG) in PPT-infected plants compared to mock controls. The MGDG/digalactosyldiacylglycerol (DGDG) ratio, an indicator of chloroplast thylakoid membrane structure and function, was reduced in PPT phytoplasma-infected plants. Additionally, the degradation of the chloroplast rubisco large and small subunits (RbcL and RbcS) was observed in infected plants, indicating the activation of chloroplast autophagy triggered by the accumulation of reactive oxygen species (ROS) resulting from lipid composition changes. These findings suggest that phytoplasma infection alters the lipid metabolism of host plants, which could contribute to the development of yellowing symptoms and reduced photosynthesis efficiency. Understanding these mechanisms could lead to the development of new disease control strategies.