APS Homepage

TECHNICAL SESSION: Advanced detection and diagnosis of plant diseases

Microneedle-based Rapid Plant DNA Extraction: Towards In-Field Detection of Plant Pathogens
Rajesh Paul - North Carolina State University. Amanda Saville- North Carolina State University, Jean Ristaino- North Carolina State University, Qingshan Wei- North Carolina State University, Guojun Chen- University of California, Xinyuan Xinyuan- Tianjin University, Alyssa Williams- North Carolina Sta

Extraction of DNA from infected plant leaves is an important step for molecular diagnosis of plant pathogens. Current laboratory-based plant DNA extraction protocols (e.g., cetyltrimethylammonium bromide (CTAB) extraction) involve multiple steps and require bulky benchtop equipment and skilled technicians. As such, sample preparation becomes a major bottleneck that constrains advanced molecular diagnosis of plant diseases in the laboratory settings. Here, a rapid DNA extraction method has been developed by using polymeric microneedle (MN) patches. This method is minimally invasive, and isolates polymerase chain reaction (PCR) amplifiable DNA within one minute from plant leaves. Furthermore, we used these MN patches to successfully extract Phytophthora infestans DNA from both laboratory-inoculated and field samples for late blight disease detection in tomato. For laboratory-inoculated samples, the MN patch-based DNA extraction method achieved 100% detection rate compared to CTAB extraction method when the samples were taken 3 days after inoculation. For field samples, the MN extraction method successfully detected P. infestans in all blind samples tested from older lesions. This simple and rapid MN patch-based DNA extraction method could be applicable to extract DNA from other plant pathogens in infected plant material directly in the field, constituting a crucial first step towards the development of an in-field molecular diagnostic platform for plant pathogens.