Modern Tools for Detection and Diagnosis of Plant Pathogens

Abstract

Plant diseases contribute to an estimated annual crop loss of $60 billion worldwide, threatening the food security and thereby the survival of humankind. Plant pathogens are an important component of the widely accepted disease triangle concept where they cause diseases in susceptible hosts under favorable environmental conditions. Under such favorable environmental conditions, pathogens often spread rapidly to new hosts. Therefore, early and accurate detection of a disease and diagnosis of its causal agent is highly important for disease control and sustainable agricultural production. This chapter provides information on an array of methods actively being used to detect and diagnose diseases. We include discussion of established methods such as microscopy and serology, indexing, and PCR as well as methods that are actively under development. An elaborate account of information is provided on promising diagnostic methods based on programmable nucleic acid-binding proteins such as clustered regularly interspaced palindromic repeat (CRISPR)-associated (CAS) proteins, zinc finger (ZnF) proteins, and transcription activator-like effector (TALE) proteins. Finally, we discuss indirect pathogen detection technologies that utilize optical sensors to identify changes in the host plant properties due to a disease.