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Ivanauskas A, Inaba J, Zhao Y, Bottner-Parker KD, Wei W. Differential Symptomology, Susceptibility, and Titer Dynamics Manifested by Phytoplasma-Infected Periwinkle and Tomato Plants. PLANTS (BASEL, SWITZERLAND) 2024; 13:787. [PMID: 38592808 PMCID: PMC10974080 DOI: 10.3390/plants13060787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/08/2024] [Accepted: 03/09/2024] [Indexed: 04/11/2024]
Abstract
Phytoplasmas are intracellular pathogenic bacteria that infect a wide range of plant species, including agriculturally important crops and ornamental trees. However, our understanding of the relationship between symptom severity, disease progression, and phytoplasma concentration remains limited due to the inability to inoculate phytoplasmas mechanically into new plant hosts. The present study investigated phytoplasma titer dynamics and symptom development in periwinkle and tomato, both infected with the same potato purple top (PPT) phytoplasma strain using a small seedling grafting approach. Virescence, phyllody, and witches'-broom (WB) symptoms sequentially developed in periwinkle, while in tomato plants, big bud (BB, a form of phyllody), cauliflower-like inflorescence (CLI), and WB appeared in order. Results from quantitative polymerase chain reaction (qPCR) targeting the PPT phytoplasma's 16S rRNA gene revealed that in both host species, phytoplasma titers differed significantly at different infection stages. Notably, the highest phytoplasma concentration in periwinkles was observed in samples displaying phyllody symptoms, whereas in tomatoes, the titer peaked at the BB stage. Western blot analysis, utilizing an antibody specific to PPT phytoplasma, confirmed substantial phytoplasma presence in samples displaying phyllody and BB symptoms, consistent with the qPCR results. These findings challenge the conventional understanding that phytoplasma infection dynamics result in a higher titer at later stages, such as WB (excessive vegetative growth), rather than in the early stage, such as phyllody (abnormal reproductive growth). Furthermore, the PPT phytoplasma titer was markedly higher in periwinkles than in tomato plants, indicating differing susceptibilities between the hosts. This study reveals distinct host responses to PPT phytoplasma infection, providing valuable insights into phytoplasma titer dynamics and symptom development, with implications for the future management of agricultural disease.
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Affiliation(s)
- Algirdas Ivanauskas
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; (A.I.); (J.I.); (Y.Z.); (K.D.B.-P.)
- Laboratory of Plant Pathology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
| | - Junichi Inaba
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; (A.I.); (J.I.); (Y.Z.); (K.D.B.-P.)
| | - Yan Zhao
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; (A.I.); (J.I.); (Y.Z.); (K.D.B.-P.)
| | - Kristi D. Bottner-Parker
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; (A.I.); (J.I.); (Y.Z.); (K.D.B.-P.)
| | - Wei Wei
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA; (A.I.); (J.I.); (Y.Z.); (K.D.B.-P.)
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Chang HC, Chen JC. An efficient grafting method for phytoplasma transmission in Catharanthus roseus. PLANT METHODS 2024; 20:13. [PMID: 38245775 PMCID: PMC10799486 DOI: 10.1186/s13007-024-01139-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/14/2024] [Indexed: 01/22/2024]
Abstract
BACKGROUND Phytoplasmas are parasitic plant pathogens that reside intracellularly within the sieve tube cells. Phytoplasmas induce various symptoms, including floral virescence, phyllody, leaf yellowing, and witches'-broom. Currently, it is challenging to culture phytoplasma in vitro. In the laboratory, phytoplasmas are generally maintained in alternative host plants, such as Catharanthus roseus. Grafting is used to transmit phytoplasmas among the alternative hosts. During the experiment, scions from infected plants are grafted onto healthy plants using a side grafting method. However, the practice has certain limitations, including its inability to be applied to small plants and its irregular disease incidence. RESULTS Here, we demonstrate a new approach, penetration grafting, to overcome the limitations of side grafting. This grafting method allows phytoplasma to be efficiently and uniformly transmitted into the inoculated plants. No significant difference was observed in phytoplasma accumulation between both grafting techniques. However, penetration grafting allows rapid symptom development, saving waiting time and reducing space usage. CONCLUSIONS This study provides a reliable and stable method for experiments that require grafting transmission.
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Affiliation(s)
- Ho-Chun Chang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Jen-Chih Chen
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC.
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 106, Taiwan, ROC.
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Pardo JM, Chittarath K, Vongphachanh P, Hang LT, Oeurn S, Arinaitwe W, Rodriguez R, Sophearith S, Malik AI, Cuellar WJ. Cassava Witches' Broom Disease in Southeast Asia: A Review of Its Distribution and Associated Symptoms. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12112217. [PMID: 37299196 DOI: 10.3390/plants12112217] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023]
Abstract
Cassava witches' broom disease (CWBD) is one of the main diseases of cassava in Southeast Asia (SEA). Affected cassava plants show reduced internodal length and proliferation of leaves (phyllody) in the middle and top part of the plant, which results in reduced root yields of 50% or more. It is thought to be caused by phytoplasma; however, despite its widespread distribution in SEA still little is known about CWBD pathology. The overarching goal of this study was to review and corroborate published information on CWBD biology and epidemiology considering recent field observations. We report the following: (1) CWBD symptoms are conserved and persistent in SEA and are distinct from what has been reported as witches' broom in Argentina and Brazil. (2) In comparison with cassava mosaic disease, another major disease of cassava in SEA, symptoms of CWBD develop later. (3) Phytoplasma detected in CWBD-affected plants belong to different ribosomal groups and there is no association study available indicating phytoplasma as the causing agent of CWBD. These findings are essential clues for designing surveillance and management strategies and for future studies to better understand the biology, tissue localization and spatial spread of CWBD in SEA and other potential risk areas.
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Affiliation(s)
- Juan M Pardo
- Cassava Program, International Center for Tropical Agriculture (CIAT), The Americas Hub, Km 17 Recta Cali-Palmira, Cali 763537, Colombia
| | - Khonesavanh Chittarath
- Plant Protection Center (PPC), Department of Agriculture, Ministry of Agriculture and Forestry, Vientiane P.O. Box 811, Laos
| | - Pinkham Vongphachanh
- Plant Protection Center (PPC), Department of Agriculture, Ministry of Agriculture and Forestry, Vientiane P.O. Box 811, Laos
| | - Le Thi Hang
- Plant Protection Research Institute (PPRI), Duc Thang, Bac Tu Liem, Ha Noi 100000, Vietnam
| | - Samoul Oeurn
- Plant Protection Sanitary and Phytosanitary Department, General Directorate of Agriculture (GDA), Phnom Penh 120406, Cambodia
| | - Warren Arinaitwe
- Cassava Program Asia Office, International Center for Tropical Agriculture (CIAT), Vientiane P.O. Box 783, Laos
| | - Rafael Rodriguez
- Cassava Program, International Center for Tropical Agriculture (CIAT), The Americas Hub, Km 17 Recta Cali-Palmira, Cali 763537, Colombia
| | - Sok Sophearith
- Cassava Program Cambodia Office, International Center for Tropical Agriculture (CIAT), Phnom Penh 120904, Cambodia
| | - Al Imran Malik
- Cassava Program Asia Office, International Center for Tropical Agriculture (CIAT), Vientiane P.O. Box 783, Laos
| | - Wilmer J Cuellar
- Cassava Program, International Center for Tropical Agriculture (CIAT), The Americas Hub, Km 17 Recta Cali-Palmira, Cali 763537, Colombia
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