Preventing Crop Loss

Problem

What can be done to prevent crop losses due to citrus greening?

• Since 2005, Candidatus Liberibacter asiaticus (CLas)—a devastating and broadly distributed bacterial pathogen that causes citrus greening or Huanglongbing (HLB)—has reduced Florida's orange crop production by more than 70 percent and has been detected in Texas, California, Georgia, and Louisiana.
• The best hope of reducing the spread of citrus greening is to eliminate diseased trees quickly, but current detection methods often fail, especially in asymptomatic tissue. Infected trees can act as a disease reservoir for months or years before showing visible symptoms.

Findings

Researchers used CRISPR/Cas technology, a powerful gene-editing technology that has been recently adapted as a molecular diagnostic tool, to develop a highly specific and sensitive assay to detect the presence of CLas nucleic acids across different infected citrus and insect vector samples.

Impact

Early detection technology for disease diagnosis and quarantine of infected crops and insect vectors can help to minimize crop loss and prevent transmission into disease-free, citrus-growing regions.

• The CRISPR/Cas method provides a sensitivity detection level 100 to 1,000 times greater than the current diagnostic tests commonly used. The assay used for this test was shown to be compatible with lateral flow technology, similar in concept to home pregnancy tests, holding promise for providing rapid and economical testing for HLB in the field.

Research Credit

Team

• Yinong Yang, Matthew S. Wheatley, Qin Wang, Yong Ping Duan

Participating Department

• Plant Pathology and Environmental Microbiology

Partners

• USDA Agricultural Research Service, U.S. Horticultural Research Laboratory

Competitive Funding

• USDA Animal and Plant Health Inspection Service (APHIS)

Federal and State Appropriations

• USDA NIFA Hatch Project PEN04659, Accession #1016432

Emerging Discoveries

CRISPR/Cas technology could enable early diagnosis of devastating citrus disease

May 10, 2021

Penn State and U.S. Department of Agriculture scientists have used cutting-edge CRISPR/Cas technology to develop a diagnostic test that could enable early diagnosis of citrus greening, or Huanglongbing, a serious disease that threatens worldwide citrus production, which is valued at roughly $17 billion from the sale of fresh fruit and juices.

Published Research

Highly Sensitive and Rapid Detection of Citrus Huanglongbing Pathogen ('Candidatus Liberibacter asiaticus') Using Cas12a-Based Methods.

• Wheatley, M. S., Duan, Y. P., & Yang, Y. (2021). Highly Sensitive and Rapid Detection of Citrus Huanglongbing Pathogen ('Candidatus Liberibacter asiaticus') Using Cas12a-Based Methods. Phytopathology, 111(12), 2375-2382. https://doi.org/10.1094/PHYTO-09-20-0443-R