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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 #353628
Research Project: Genome-Based Strategies and Physiological Biomarkers for Detection and Identification of plant Pathogenic Phytoplasmas and Spiroplasmas

Location: Molecular Plant Pathology Laboratory

Title: Transcriptome analysis reveals a complex array of differentially expressed genes accompanying a source-to-sink changes in phytoplasma-infected sweet cherry leaves

Author
item TAN, YUE - Shandong Institute
item WANG, JIAWEI - Shandong Institute
item Davis, Robert
item WEI, HAIRONG - Shandong Institute
item ZONG, XIAOJUAN - Shandong Institute
item Wei, Wei
item Shao, Jonathan
item Zhao, Yan
item LIU, Q - Shandong Institute

Submitted to: Annals of Applied Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sweet cherry (Prunus avium L.) is a popular deciduous tree highly valued for its fruit and timber. Recently, sweet cherry trees in China have been affected by a destructive disease associated with infection by a small bacterium called phytoplasma. A previous study revealed that photosynthetic activity had significantly declined in leaves of such diseased trees. To gain a deeper understanding of the disease, ARS scientists and their colleagues in China jointly performed a large-scale gene expression study (transcriptomic analysis), comparing expression profiles of the entire set of host genes in leaves of diseased versus healthy sweet cherry trees. The study identified more than a thousand genes whose expression levels were altered in the diseased trees. Phytoplasma infection induced the up-regulation of a suite of genes involved in carbohydrate metabolism, fatty acid biosynthesis, phenylpropanoid biosynthesis, and flavonoid biosynthesis. Expression levels of genes related to amino acid metabolism and hormonal balance were also significantly changed. Findings from this study provide leads to elucidating host responses to the bacterial infection and mechanisms of disease induction. This report will be of interest to research scientists who are studying pathogen-host interactions and molecular basis of phytoplasmal diseases. The information is also important to diagnosticians and extension personnel who are concerned with phytoplasmal disease management.

Technical Abstract: Sweet cherry (Prunus avium) in China has recently been affected by a destructive disease that is characterized by symptoms of floral virescence and witches’-broom growths. The etiological agent of the disease is a subgroup 16SrV-B phytoplasma that is closely related to ‘Candidatus Phytoplasma ziziphi’. A previous study revealed that photosynthetic activity had significantly declined in symptomatic leaves of the diseased sweet cherry trees. For a deeper view into the infection, we performed a comparative transcriptomic analysis. A total of 62,410 unigenes were identified; among them, 1,675 were differentially expressed in symptomatic leaves of diseased versus asymptomatic leaves of healthy plants. Phytoplasma infection induced the up-regulation of a suite of genes involved in carbohydrate metabolism, fatty acid biosynthesis, phenylpropanoid biosynthesis and flavonoid biosynthesis. Expression profiles of genes related to amino acid metabolism, hormone metabolism, and signal transductions were also altered in leaves of phytoplasma-infected trees. Findings from this study offer clues to understanding host responses to the phytoplasma infection and disease induction in sweet cherry trees.