RNA-based
Antiviral for Plants – SCIENCE & TECHNOLOGY
NEWS: Scientists have developed an RNA-based
antiviral technology that significantly strengthens plant immunity against
devastating viral infections, especially the cucumber mosaic virus (CMV).
WHAT’S IN THE NEWS?
Overview of RNA-Based Antiviral Approach
- Innovation
Origin: Developed by a research team at Martin Luther University
Halle-Wittenberg, Germany, the RNA-based antiviral offers a
next-generation defence strategy against plant viruses.
- Mechanism
of Action: This method involves engineering double-stranded RNA
(dsRNA), which is rich in small interfering RNAs (siRNAs), to initiate a
strong immune response in plants.
- Immune
Trigger: The dsRNA is recognized by the plant’s immune system and
processed into siRNAs, which then target and degrade the viral RNA with
high precision.
- Spray-Based
Application: The antiviral can be delivered as a foliar spray,
offering a non-genetically modified (non-GMO) solution that does not alter
plant DNA.
Advantages of the RNA-Based Antiviral
- Precision
Targeting: Engineered siRNAs are designed to match and silence the
most vulnerable parts of the viral genome, ensuring high specificity and
efficiency.
- Stronger
and Durable Defence: The method enhances siRNA concentration within
the plant, providing robust and longer-lasting protection against various
virus strains.
- Non-GMO
Solution: Since it is applied externally as a spray, it bypasses the
concerns associated with genetically modifying crops.
- Adaptability:
The dsRNA can be rapidly redesigned to counter new or mutating virus
strains, making it a versatile and future-proof approach.
Potential Agricultural Impact
- Reduction
in Crop Losses: Could significantly mitigate the economic burden
caused by plant viruses, which currently result in over $30 billion in
losses annually.
- Improved
Food Security: Enhances the resilience of crops to viral threats,
ensuring more stable food supplies, especially critical in regions heavily
dependent on agriculture.
- Support
for Sustainable Agriculture: Offers an eco-friendly solution that
aligns with the principles of integrated pest management and sustainable
farming practices.
Challenges and Future Prospects
- RNA
Stability: RNA molecules are prone to degradation under field
conditions, which may limit their efficacy unless stabilized.
- Scalability
of Production: Producing large volumes of dsRNA at a feasible cost
remains a challenge for commercial deployment.
- Regulatory
Hurdles: Approval from agricultural and environmental regulatory
bodies is necessary before this technology can be widely adopted.
- Farmer
Readiness: Adequate training and awareness among farmers are essential
for the successful implementation of this new technology.
About Cucumber Mosaic Virus (CMV)
- Host
Range: CMV infects over 1,200 plant species, including vegetables,
fruits, and ornamental plants, causing significant economic losses.
- Transmission:
Mainly spread by aphids in a non-persistent manner; also transmittable
through infected seeds and mechanical contact.
- Symptoms:
Causes mosaic patterns on leaves, stunted growth, distortion of plant
parts, and significant yield reductions.
- Management
Difficulty: Its broad host range and multiple transmission modes make
CMV particularly hard to control.
Viral Infections in Plants: General Background
- Nature
of Infection: Plant viruses enter cells and hijack their replication
machinery, leading to cellular damage and disrupted plant function.
- Common
Plant Viruses: Include CMV, Tomato Yellow Leaf Curl Virus, Potato
Virus Y, and Tobacco Mosaic Virus, among others.
- Symptoms:
Include mosaic leaf patterns, leaf curling, chlorosis, fruit malformation,
and plant death in severe cases.
Economic and Agricultural Impact of Plant Viruses
- Yield
Reduction: Viral infections can lead to yield losses of 25–70%, posing
a major risk to agricultural profitability.
- Global
Financial Loss: UN FAO estimates that pests and diseases destroy
around 40% of crops annually, with viruses causing $30 billion of this
loss.
- Plant
Health Decline: Infected plants suffer stunted growth and produce
unmarketable or lower-quality produce.
Factors Contributing to Viral Spread
- Rapid
Viral Mutation: High mutation rates in viruses allow them to evade
natural plant immunity and resist control measures.
- Vector
Proliferation: Sap-sucking insects like aphids are major carriers;
nearly 90 aphid species can transmit CMV alone.
- Climate
Change Effects: Rising temperatures and shifting rainfall patterns
expand the habitat of vectors, intensifying viral outbreaks.
- Absence
of Direct Treatments: Unlike fungal or bacterial infections, there are
currently no direct antiviral treatments available for plants.
India’s Vulnerability to Plant Viral Infections
- Severe
Yield Losses: CMV alone results in 25–30% yield losses in bananas and
up to 70% in crops like cucumber, pumpkin, and melon.
- Wide
Crop Diversity: India’s agricultural system includes many
virus-susceptible crops, increasing its exposure to viral threats.
- Favorable
Conditions for Vectors: Warm temperatures and monsoon humidity create ideal
breeding conditions for aphids and other vectors.
Way Forward
- Promoting
Technological Adoption: Farmers should be trained and incentivized to
use RNA-based antivirals such as Spray-Induced Gene Silencing (SIGS).
- Combining
with Traditional Practices: Integrating RNA technology with methods
like crop rotation, resistant varieties, and vector management enhances
effectiveness.
- Farmer
Awareness Campaigns: Outreach programs are essential to inform farmers
about viral threats and modern protective strategies.
- Governmental
Support: Policymakers must prioritize regulatory clearance, financial
assistance for farmers, and support for field trials and public-private
collaborations.
Source: https://www.thehindu.com/sci-tech/energy-and-environment/rna-based-antiviral-offers-strong-defence-against-cucumber-mosaic-virus/article69497221.ece