A Powerful LAMP Weapon against the Threat of the Quarantine Plant Pathogen Curtobacterium flaccumfaciens pv. flaccumfaciens

Abstract

Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff) is a Gram-positive phytopathogenic bacterium attacking leguminous crops and causing systemic diseases such as the bacterial wilt of beans and bacterial spot of soybeans. Since the early 20th century, Cff is reported to be present in North America, where it still causes high economic losses. Currently, Cff is an emerging plant pathogen, rapidly spreading worldwide and occurring in many bean-producing countries. Infected seeds are the main dissemination pathway for Cff, both over short and long distances. Cff remains viable in the seeds for long times, even in field conditions. According to the most recent EU legislation, Cff is included among the quarantine pests not known to occur in the Union territory, and for which the phytosanitary inspection consists mainly of the visual examination of imported bean seeds. The seedborne nature of Cff combined with the globalization of trades urgently call for the implementation of a highly specific diagnostic test for Cff, to be routinely and easily used at the official ports of entry and into the fields. This paper reports the development of a LAMP (Loop-Mediated Isothermal Amplification) specific for Cff, that allows the detection of Cff in infected seeds, both by fluorescence and visual monitoring, after 30 min of reaction and with a detection limit at around 4 fg/μL of pure Cff genomic DNA.

The Potential Use of Isothermal Amplification Assays for In-Field Diagnostics of Plant Pathogens

“…The most observable colorimetric method of detection is those that involve pH changes. A developing yellow colour in a positive LAMP reaction is easily distinguishable from a pink negative sample [157][158][159][160]. The opposite colorization is also available [161][162][163].…”

Detection and Control of Pantoea agglomerans Causing Plum Bacterial Shot-Hole Disease by Loop-Mediated Isothermal Amplification Technique

“…pruni could be detected within 15 min by using real-time LAMP (Li et al, 2019 ). Tegli et al ( 2020 ) established a LAMP method for detecting Curtobacterium flaccumfaciens pv. flaccumfaciens after 30 min and the detection limit was reduced to 4 fg·μl −1 of genomic DNA.…”