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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 #363871
Research Project: Genome-Based Strategies and Physiological Biomarkers for Detection and Identification of plant Pathogenic Phytoplasmas and Spiroplasmas

Location: Molecular Plant Pathology Laboratory

Title: Phytoplasma inoculum titre and inoculation timing influence symptom development in newly infected plants

Author
item Wei, Wei
item Zhao, Yan
item Davis, Robert

Submitted to: Phytopathogenic Mollicutes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2019
Publication Date: 6/30/2019
Citation: Wei, W., Zhao, Y., Davis, R.E. 2019. Phytoplasma inoculum titre and inoculation timing influence symptom development in newly infected plants . Phytopathogenic Mollicutes. 9/115-116. https://doi.org/10.5958/2249-4677.2019.00058.6.
DOI: https://doi.org/10.5958/2249-4677.2019.00058.6

Interpretive Summary: Phytoplasmas are small and wall-less bacteria. Phytoplasma infection can override genetically predetermined fate of plant stem cells, inducing symptoms that change plant morphology. In a previous study, ARS scientists identified four sequentially developed symptoms in phytoplasma-infected tomato plants. In the present study, the ARS scientists modified inoculation parameters by changing bacterial inoculum titer and inoculation timing. The researchers unveiled that both phytoplasma inoculum titer and inoculation timing could significantly influence the symptom development in infected plants and induce different combinations of symptoms. Findings from the study will help understand interactions between host plant and phytoplasmas. The information is important to research scientists, students, and university professors who are studying plant growth and development, pathogen-host interactions, and disease symptom management.

Technical Abstract: Our previous study unveiled that a single phytoplasma infection may induce mutually distinct symptoms in a single host plant. Four sequentially-developed symptoms were identified in potato purple top (PPT) phytoplasma-infected tomato plants. The symptoms included big bud (BB), cauliflower-like inflorescence (CLI), disrupted sympodial growth patter (DSGP), and witches'-broom growth (WB). In the present study, we graft-inoculated tomato seedling at different developmental stages and with PPT phytoplasma inocula of different titres. Our results indicated that both phytoplasma inoculum titre and inoculation timing could influence the symptom development in infected plants. Findings from the study support the notion that the type of symptoms in any given shoot is determined by the developmental stage of the shoot apex when it became affected by the phytoplasma.