Huck Institutes of the Life Sciences

Researchers receive $3.6 million to study genetics of plant disease resistance

Cacao seed pods in Costa Rica display symptoms of fungal black pod disease. A National Science Foundation grant will enable researchers to study the genetic basis of disease resistance in cacao. Credit: Christopher J. Saunders, Bugwood.orgAll Rights Reserved.

UNIVERSITY PARK, Pa. — A $3.6 million grant from the National Science Foundation will support a new research project aimed at pinpointing the genes that confer disease resistance in cacao.

The ultimate goal of the four-year study is to develop a new approach that plant scientists and breeders can use to identify the genetic basis for disease resistance in a variety of perennial crops, according to lead researcher Mark Guiltinan, professor of plant molecular biology in Penn State's College of Agricultural Sciences.

"Because of the longer life cycle of perennial crops — particularly long-lived tree crops — finding resistance genes is more difficult and time consuming than it is in short-rotation annual crops," Guiltinan said.

"This project will explore the plant immune system via a comprehensive study of the genes important for resistance to key pathogens of cacao, which is the source of chocolate and an important cash crop for millions of farmers in developing countries," he said. "The methods, tools and knowledge gained will be directly applicable to discovery of genes underlying important traits in other crops, especially trees and many perennial grasses."

Guiltinan said the interdisciplinary team, which includes plant evolutionary biologists and functional genomicists, will study 24 cacao varieties divided into three genetic groups, each containing eight plants — four that are susceptible to disease and four that are resistant. The researchers will extract DNA and sequence the plants' genomes, while also looking at gene expression.

"When a pathogen attacks a plant, it injects proteins that interact with proteins in the plant," he explained. "We want to better understand this interaction and determine which genes are involved. Functional analysis of these genes will test their role in resistance and set the stage for future translation of these basic findings to guide more efficient breeding programs utilizing a wider array of genetic diversity."

Guiltinan noted that the project could help enhance food and economic security for a growing world population that experts project will reach 9.6 billion by 2050, requiring a 50 percent increase in food and fiber production.

"A major constraint to increased food production is crop losses due to microbial plant diseases, which destroy about 15 percent of the world's total crop production every year," he said. "Advances in the science of plant disease control are needed to reduce these disease-related losses."

He said the project also will build genomics research capacity in developing countries through scientific exchanges between project members and international collaborators, and will provide postdoctoral, graduate and undergraduate student training at multiple institutions.

The research team also includes Siela Maximova, senior scientist and professor of horticulture, Claude dePamphilis, professor of biology, and James Marden, professor of biology, Penn State; and Peter Tiffin, professor of plant and microbial biology, University of Minnesota.

Last Updated January 6, 2017

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