Page Banner

United States Department of Agriculture

Agricultural Research Service

Agricultural Research Service
U.S. Department of Agriculture
ARS News and InformationSearch News and InfoScience for KidsImage GalleryAgricultural Research MagazinePublications and NewslettersNews ArchiveNews and Info homeARS News and Information
Latest news | Subscribe

Photo: Technician Donald Brummett (left) and plant physiologist Steve Crafts-Brandner measure photosynthesis in an Arizona cotton field. Link to photo information
Click image for caption and other photo information.

Read the magazine story to find out more.

Robust Plants' Secret? Rubisco Activase!

By Marcia Wood
November 22, 2002

Green plants must have a hardworking enzyme--called rubisco--in their leaves in order to grow. Ongoing investigations by Agricultural Research Service scientists in Phoenix, Ariz., have uncovered secrets about the pivotal role of a companion enzyme, rubisco activase.

Rubisco activase helps convert rubisco from an inactive to an active form. That's essential. Only active rubisco can help plants convert sunlight, water from the soil, and carbon dioxide from the air into food that they need for growth.

This process--called photosynthesis--slows if leaf cells have more inactive than active rubisco. The result? Plants don't grow as fast, and harvests aren't as bountiful, according to plant physiologist Steven J. Crafts-Brandner of the ARS Western Cotton Research Laboratory in Phoenix. He did the rubisco activase studies with Michael E. Salvucci, also a plant physiologist at the laboratory.

A plant could end up with more inactive than active rubisco if rubisco activase is inhibited by high temperatures or high carbon dioxide, the scientists found. No one had previously identified rubisco activase as the culprit that limits photosynthesis under these climatic conditions.

Damage-causing high temperatures can occur in the arid Southwest as well as in the South and Southeast. And, worldwide records of the past 100 years indicate a gradual warming trend and an increase in atmospheric carbon dioxide. Some experts predict both trends will continue.

The research should not only boost the accuracy of projections about how global climate change might affect green plants but should also lead to new strategies to help crop plants sidestep the unwanted, climate-driven influences on rubisco activase. For instance, Crafts-Brandner and Salvucci hope to find or construct genes that could cue plants to synthesize a more heat-stable rubisco activase. They're collaborating with Pioneer Hi-Bred International, Inc., of Des Moines, Iowa., in the research.

An article in the current issue of Agricultural Research magazine tells more.

ARS is the U.S. Department of Agriculture's chief scientific research agency.

Top|News Staff|Photo Staff

E-mail the web teamPrivacy and other policiesSite mapAbout ARS Information StaffBottom menu

Home | News | Pubs | Magazine | Photos | Sci4Kids | Search
About ARS Info | Site map | Policies | E-mail us

Last Modified: 8/22/2017
Footer Content Back to Top of Page