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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 #420648
Research Project: Omics-Based Approach to Detection, Identification, and Systematics of Plant Pathogenic Phytoplasmas and Spiroplasmas

Location: Molecular Plant Pathology Laboratory

Title: Convolvulus arvensis is a novel host of 'Candidatus Phytoplasma Omanense'-related strains causing Little Leaf Disease in Jordan

Author
item ABU ALLOUSH, ASEM - National Agriculture Research Center(NARC)
item Inaba, Junichi
item Bottner-Parker, Kristi
item Shao, Jonathan
item OBEIDAT, NIZAR - National Agriculture Research Center(NARC)
item Wei, Wei

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2025
Publication Date: 4/8/2025
Citation: Abu Alloush, A.H., Inaba, J., Bottner-Parker, K.D., Shao, J.Y., Obeidat, N., Wei, W. 2025. Convolvulus arvensis is a novel host of 'Candidatus Phytoplasma Omanense'-related strains causing Little Leaf Disease in Jordan. Plant Disease. https://doi.org/10.1094/PDIS-12-24-2635-PDN.
DOI: https://doi.org/10.1094/PDIS-12-24-2635-PDN

Interpretive Summary: Since 2023, field bindweed, an invasive perennial weed native to Europe and Asia, has been observed in Kharja, Jordan, displaying symptoms such as little leaf, discoloration, thickening, and stunted growth. ARS scientists in Beltsville, Maryland, suspected that these symptoms might be linked to a phytoplasma infection. In collaboration with Jordanian scientists, ARS researchers conducted molecular detection using specific genetic markers for phytoplasmas. The results confirmed the presence of phytoplasmas and identified them as new strains belonging to the 16SrXXIX taxonomic group, representing a new subgroup (16SrXXIX-C). This marks the first documented case of 16SrXXIX strains in bindweed in Jordan. This finding enhances our understanding of the diversity of phytoplasmas associated with bindweed. Given the invasive nature of bindweed and its capacity to transmit phytoplasmas, it is essential to recognize the increased risk to local crops and agricultural health. The findings are crucial for researchers studying phytoplasma detection and diversity while also providing important guidance for extension personnel and farmers in developing effective disease management strategies to protect crops from potential outbreaks.

Technical Abstract: In July 2023, field bindweed (Convolvulus arvensis), an invasive perennial weed, exhibited symptoms of little leaf, discoloration, thickening, and stunted growth in a 0.3-hectare green cherry orchard in Kharja, Jordan. These symptoms were observed in 20 out of 35 plants, indicating a 57% incidence rate. Given the role of bindweed as a known phytoplasma host and the similarity of symptoms to phytoplasma infections, DNA was extracted from six symptomatic plants and two healthy controls. PCR assays targeting the phytoplasma 16S rRNA gene confirmed infection in all symptomatic plants, while healthy controls tested negative. iPhyClassifier analysis identified the strain associated with field bindweed little leaf (FBLL) disease as a 'Candidatus Phytoplasma omanense'-related strain, which belongs to the 16SrXXIX group and represents a novel subgroup, 16SrXXIX-C. The strain was designated as FBLL1. Further characterization of FBLL1 involved amplification and sequencing of the rp and secY genes. BLASTN analysis showed 75.60% identity of the rp gene to 'Ca. P. pruni' and 73.47% identity of the secY gene to 'Ca. P. phoenicium'. This is the first report of 16SrXXIX-related strains in bindweed, expanding the known diversity of phytoplasmas associated with this weed. The rapid spread of bindweed and its role as a phytoplasma reservoir increases the risk of crop disease transmission, highlighting the need for enhanced monitoring and management strategies to protect agricultural biosecurity.