Scientists Plot Genetic Ploy Against Grain Pest

November 3, 2009 By Jan Suszkiw
Scientists Plot Genetic Ploy Against Grain Pest
Red flour beetle (Tribolium castaneum).

(PhysOrg.com) -- Aided by a genomic map of the red flour beetle, Tribolium castaneum, Agricultural Research Service (ARS) and university scientists are plotting a kind of genetic sabotage on the pest’s basic life functions -- from locomotion to digestion.

Nationally, infestations of flour beetles and their beetle cousins cost millions of dollars in losses annually to stored grains and the food products made from those grains. Warehouse sanitation usually keeps beetle numbers down, but severe cases can necessitate the use of chemical controls. The problem is that T. castaneum has shown a propensity for developing resistance to insecticides.

As an alternative, a team of ARS and Kansas State University scientists is examining ways to exploit specific genes that regulate where, when and how a substance called chitin is used to form the beetle’s outer shell, or exoskeleton.

Led by ARS entomologist Richard Beeman, the team identified nine genes encoding specialized enzymes, dubbed “chitin deacetylases” (CDAs), which trim off branches of a long chain of simple sugars that make up raw chitin.

Which branches get trimmed depends on where chitin is needed on a developing beetle’s body, and for what purpose, explains Beeman, with the ARS Stored Product Insect Research Unit in Manhattan, Kan. For example, around leg joints, chitin’s branched-chain structure must be snipped to allow for flexibility and movement. But around the head and thorax, where protection of vital organs is key, a heavier, stiffer chitin deposition is needed, requiring a different form of CDA trimming.

Beeman and KSU collaborators Subbaratnam Muthukrishnan and Yasuyuki Arakane used a biotech procedure called “” to demarcate the genes’ roles and observe what effect their elimination had on the insect’s development or survival. Some CDA-deficient strains developed in the lab couldn’t bend their legs as adult beetles, making it impossible for them to walk, mate or feed. Another such strain couldn’t shed its old .

Ultimately, such observations could open the door to chitin-disabling biopesticides or anti-chitin proteins engineered into crop plants.

Read more about this research in the November/December 2009 issue of Agricultural Research magazine.

Provided by USDA Agricultural Research Service

Explore further: New molecule may aid in production of biofuels and fungi-resistant plants

Related Stories

Study discovers how beetle shells harden

August 5, 2005

Kansas State University researchers think their discovery of the enzyme involved in the hardening of a beetle's exoskeleton or cuticle could lead not only to better pest control, but also help create similar strong, lightweight ...

Biologists sequenced red flour beetle genome

March 23, 2008

Most of us hate to find the red flour beetle living happily in the flour sack in our pantries. But for several scientists at Kansas State University, and many others throughout the world, this pest of stored grain and grain ...

Hardy New Corn Lines Released

October 16, 2009

(PhysOrg.com) -- Six new inbred maize lines with resistance to aflatoxin contamination have now been registered in the United States by the Agricultural Research Service (ARS). ARS plant pathologist Robert Brown and colleague ...

Recommended for you

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

Plants also suffer from stress

September 4, 2015

High salt in soil dramatically stresses plant biology and reduces the growth and yield of crops. Now researchers have found specific proteins that allow plants to grow better under salt stress, and may help breed future generations ...

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.