Researchers find tobacco protein enhances crop immune systems

July 11, 2012 By Aya Kawanishi
The tobacco plant's protein could be used to enhance existing crop immune systems. Credit: Dennis Tang

A study led by Associate Prof. Kenji Nakahara at Hokkaido University in Japan has found a component in tobacco that makes crop immune systems more resistant to viral attacks.

Although crops have a general defense mechanism in order to fight against viruses, their invaders counteract this defense by suppressing the plant immune response. Evidence from recent studies implied that plants have developed an additional set of countermeasures to combat the virus’s immune suppression tactics.

In order to examine how plants do this, the researchers set out to find the mechanisms involved. Their results appear in the Proceedings of the National Academy of Sciences (PNAS).

They found rgs-CaM, otherwise known as “ calmodulin-like protein”, a calcium-binding messenger protein (Calmodulin is an abbreviation for “CALcium MODulated proteIN). In tobacco this binds to the viral (RNA interference) suppressors (molecules produced by the virus that chemically counteract the plants’ own defenses) and inhibits the virus from impeding the plant’s defenses.

Tobacco calmodulin-like protein binds to RNAi suppressors and sequesters them in corporation with autophagy, allowing RNAi, which was previously attenuated by the suppressors, to operate the defense mechanism properly. Credit: Kenji S. Nakahara

These findings have the potential to enhance the immune systems for crops that are vulnerable to pesticide-resistant viruses. The results of this research may well have an impact beyond tobacco crops. “Because most viruses encode RNAi suppressors, this study may contribute to the development of a molecular breeding strategy to confer resistance other viruses in crops,” said Associate Prof. Nakahara.

Explore further: Plant virus spreads by making life easy for crop pests

More information: Kenji S. Nakahara, Chikara Masuta, Syouta Yamada et al. Tobacco calmodulin-like protein provides secondary defense by binding to and directing degradation of virus RNA silencing suppressors. Proceedings of the National Academy of Sciences. 2012 Jun 19;109(25):10113-8. Epub 2012 Jun 4. doi: 10.1073/pnas.1201628109

Related Stories

Plant virus spreads by making life easy for crop pests

October 30, 2008

(PhysOrg.com) -- In 752, Japanese Empress Koken wrote a short poem about the summertime yellowing of a field in what is thought to be the first account of a viral plant disease. More than 1,250 years later, scientists concluded ...

Researchers clarify bacterial resistance

June 24, 2011

Just like plants and animals, bacteria have a range of defence mechanisms against viruses and other threats. Dutch researchers at the Wageningen Laboratory for Microbiology and their American and Russian colleagues have largely ...

Invigorating plants

July 7, 2011

One of the key elements of the Green Revolution – when a series of  agricultural initiatives dramatically boosted crop productivity worldwide – was the harnessing of hybrid vigour. This phenomenon occurs when ...

Major breakthrough on how viruses infect plants

July 14, 2011

(PhysOrg.com) -- CSIRO plant scientists have shed light on a problem that has puzzled researchers since the first virus was discovered in 1892 – how exactly do they cause disease?

Recommended for you

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

Rare nautilus sighted for the first time in three decades

August 25, 2015

In early August, biologist Peter Ward returned from the South Pacific with news that he encountered an old friend, one he hadn't seen in over three decades. The University of Washington professor had seen what he considers ...

Why a mutant rice called Big Grain1 yields such big grains

August 24, 2015

(Phys.org)—Rice is one of the most important staple crops grown by humans—very possibly the most important in history. With 4.3 billion inhabitants, Asia is home to 60 percent of the world's population, so it's unsurprising ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.