Scientists Decode How Plants Use Molecular Traps To Fight Viruses

Scientists have decoded the 'sticky' molecular traps plants use to fight viral infections, paving the way for more resilient crops and potential treatments for human diseases.

Scientists of CSIR-CCMB here have decoded 'sticky' molecular traps used by plants to arrest viral infections.

Understanding Plant's Viral Defence Mechanisms

The Centre for Cellular and Molecular Biology (CCMB) on Wednesday said the study would help design plants that are more resilient to devastating viral outbreaks and can treat human diseases such as dementia.

A CCMB release said plants are known to use liquid-like, sticky protein droplets to trap and disable invading viruses.

The study, led by Mandar V Deshmukh, and published in the Journal of the American Chemical Society (JACS), provides a molecular-level mechanism for this process.

The release said many viruses contain double-stranded RNA as their genetic material. Plants produce certain proteins more when they are infected by viruses, which can identify the viral RNAs. They are called RNA-binding proteins.

Some of the RNA-binding proteins can bind to the virus's genetic machinery (at positions called the Viral Replication Complexes) and stall the genetic machinery from dividing.

Unable to divide its genetic material, a virus fails to replicate itself in infected cells. However, the details of the proteins binding to the RNA remained a mystery, it said.

The Role of RNA-Binding Proteins

Traditionally, RNA-binding proteins have been assumed to latch onto double-stranded RNA, simply like a key fits into a lock.

However, using advanced techniques, the CCMB scientists found more to these lock and key structures. They discovered a unique fold in double-stranded RNA-binding proteins.

"In this fold, electric charges are distributed on the surface of the proteins such that they create sticky patches. Positive electric charges attract negative charges. These charges are distributed across the proteins, attracting and binding them to one another. This interconnected mesh of proteins forms dense, gel-like droplets," it said.

"These proteins act like a molecular glue. By forming these dense, gel-like droplets, the plant cells effectively trap the viral RNA, preventing it from interacting with the machinery needed for replication," said Jaydeep Paul, first author of the study.

Implications for Agriculture and Human Health

The droplets, also known as biomolecular condensates, represent a shift in how scientists understand a living cell, the release said.

For agriculture, this discovery opens new avenues for developing crop varieties with enhanced natural immunity.

By mimicking or strengthening these protein-based traps, scientists can design plants that are more resilient to devastating viral outbreaks that cause billions of dollars in crop losses globally.

In human cells, the study opens up the possibility for scientists to manipulate the sticky protein patches, to dissolve neurotoxic clumps associated with dementia or dismantle liquid barriers that protect growing tumours, it said.

Moreover, a thorough understanding of the molecular mechanisms would allow scientists to design drugs that precisely manipulate the sticky protein patches, the release added.