By JORDAN STRICKLER

Kentucky Correspondent

LEXINGTON, Ky. — Anthracnose stalk rot, one of the most prevalent stalk rots in the eastern United States, is the center of a $1.25 million grant to University of Kentucky (UK) researcher Lisa Vaillancourt.

Vailancourt, a plant pathologist, received the grant from Plant Biotic Interactions Program, a joint venture between the USDA and the National Science Foundation. The goal of the grant is to further examine an anthracnose mutant produced in her lab that is unable to cause the stalk rot disease in corn plants, which could provide a major setback to the rot.

Anthracnose has been shown to provide yield losses anywhere from 40-80 percent. “This project could give us insight into the basic biology of fungal secretion, and it could be a good target for controlling plant pathogenic fungi including biotrophic pathogens like rusts and mildew,” said Vaillancourt.

Affected plants have shredded piths and die prematurely. Anthracnose rot symptoms of the lower stalk can begin soon after tasseling, but surface discoloration and lodging usually occur later. Anthracnose also causes a distinctive blackening of the stalk rind.

The disease generally overwinters in corn residue and infects plants through the roots or by spores that splash onto the stalk or are carried by insects that may introduce them into feeding wounds. Seedlings can be infected, and some plants may die before pollination.

The disease usually does not appear until late in the season and occurs more severely where corn follows corn, especially in reduced tillage.

Vaillancourt has learned the mutant is not able to secrete certain small proteins called effectors. These effectors typically shut down a plant’s defense system and allow the disease to spread throughout the plant. The center of her study is based on a specific protein that has appeared to regulate this process.

Scientists have known about this protein’s existence as part of the secretory system in all living organisms except bacteria; however, little is known about its function, and a specific role in the regulation of effector secretion was not previously suspected.

“It appears that yield loss was 197.8 million bushels in 2016, which is a very significant loss,” said Mark Lambert, senior communications manager for the National Corn Growers Assoc. “Working on solving these disease and pest problems is important because it affects growers’ profits when they are operating on thin margins.

“It will also become more and more important to the public in the future as the population grows, corn demand grows and we see corn acreage remain flat or decline.”

During their research of the mutant, Vaillancourt – along with research collaborator Ken Jones, an extension professor in the Department of Community and Leadership Development at UK – will lead an outreach effort for middle-school students and their teachers, to give them a better understanding of the genetics of diseases and other biological processes. Many of the activities they engage in will be based on findings in her lab.