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Agricultural Losses: Plant viruses cause over $30 billion in annual global losses, with pests and diseases destroying nearly 40% of annual crops.
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Cucumber Mosaic Virus (CMV): CMV infects over 1,200 plant species, causing significant yield losses (e.g., 25-30% in Indian banana plantations, up to 70% in pumpkin/cucumber/melon crops). Spread by aphids.
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RNA Silencing: Plants naturally use RNA silencing (dsRNA triggers DCL enzymes to produce siRNAs, destroying viral RNA) as a defense against viruses.
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HIGS vs. SIGS: Host-Induced Gene Silencing (HIGS) involves genetically modifying plants for continuous dsRNA production but faces regulatory and cost hurdles. Spray-Induced Gene Silencing (SIGS) uses RNA sprays, but traditional dsRNA mixes are inefficient.
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New “Effective dsRNA” Approach: Researchers developed a new approach that enhanced the effectiveness of RNA silencing against CMV.
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Engineered dsRNA: Genetically engineered dsRNA enriched with highly functional siRNA.
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Key Advantages: The new approach: (i) precision, directing the plant’s immune system toward the viral particles’ most vulnerable genetic regions, boosting its ability to fight infection. (ii) a stronger defense because the more-effective dsRNA targets multiple regions of the viral genome simultaneously, making it harder for the virus to mutate and escape. (iii) effective dsRNA can be redesigned in about a month to target new viral strains.
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Promising Results: Demonstrated up to 80% viral load reduction in lab settings using Nicotiana benthamiana. Effective against multiple CMV strains.
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Future Steps: Developing spray-based solutions and field trials are underway to test effectiveness in natural conditions.
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Broader Applications: The technology could be adapted for other plant viruses, fungal and bacterial diseases, and insect pests.
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Challenges: RNA stability in outdoor conditions (sunlight, rain), cost and scalability of production, and regulatory approvals.
