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Roles of two distinct alphasatellites modulating geminivirus pathogenesis
Manish Kumar1, Fauzia Zarreen1, Supriya Chakraborty2
1Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
Virology Journal
|December 14, 2021
Summary
Alphasatellites, such as CLCuMuA and GDarSLA, were found to reduce disease symptoms and helper virus accumulation in hollyhock plants. These findings highlight the role of alphasatellites in plant defense mechanisms.
Area of Science:
- Plant Virology
- Molecular Plant Pathology
- Genetics
Background:
- Alphasatellites are small DNA satellites often accompanying begomoviruses and betasatellites, influencing disease severity.
- Two specific alphasatellites, Cotton leaf curl Multan alphasatellite (CLCuMuA) and Gossypium darwinii symptomless alphasatellite (GDarSLA), were identified in hollyhock plants with yellow mosaic disease.
- These alphasatellites were associated with Cotton leaf curl Multan virus-India (CLCuMuV-IN) and Ludwigia leaf distortion betasatellite (LuLDB).
Purpose of the Study:
- To investigate the role of CLCuMuA and GDarSLA alphasatellites in modulating disease symptoms and viral replication in hollyhock plants.
- To determine the effect of these alphasatellites on the accumulation of their helper virus (CLCuMuV-IN) and associated betasatellite (LuLDB).
- To analyze the phylogenetic and genetic diversity of the studied alphasatellites.
Main Methods:
- Generation of tandem repeat constructs of CLCuMuA and GDarSLA.
- Co-agroinoculation of Nicotiana benthamiana plants with CLCuMuV-IN, LuLDB, and either CLCuMuA or GDarSLA.
- Quantification of viral DNA using qPCR at 7, 14, and 21 days post-inoculation.
- Phylogenetic analysis using MEGA-X and genetic diversity analysis using DnaSP.
Main Results:
- The presence of CLCuMuA and GDarSLA attenuated and delayed symptom development in N. benthamiana.
- Accumulation of the helper virus CLCuMuV-IN was reduced in plants harboring either alphasatellite.
- No significant change was observed in the accumulation levels of the associated betasatellite, LuLDB.
Conclusions:
- Alphasatellites play a significant role in modulating disease symptoms and suppressing helper virus replication.
- These alphasatellites do not appear to affect the replication of their associated betasatellites.
- Understanding the evolutionary dynamics and host-defense contributions of alphasatellites is crucial for developing effective plant disease resistance strategies.
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