Development of a SYBR green-based real-time PCR assay for distinguishing the edible plant Allium microdictyon from the toxic plant Convallaria majalis and its application

Abstract

Consumption of wild plants is a common practice globally; however, not all plants are safe for human consumption, as some are toxic. Toxic plants often resemble edible species, which makes their identification difficult, particularly for non-experts. Convallaria majalis, a poisonous plant containing cardiac glycosides, poses a significant danger if mistakenly ingested. Allium microdictyon is a popular edible wild vegetable in East Asia. Owing to their similar appearance, accidental mixing can occur during harvesting or processing. In this study, specific primer pairs were designed to target chloroplast genes to distinguish the edible plant Allium microdictyon from the toxic plant Convallaria majalis, and their practicality was tested. The specificity, sensitivity, and applicability of the quantitative real-time PCR assay were evaluated using all primer pairs. Six primer sets (three for A. microdictyon and three for C. majalis) exhibited strong linearity, with correlation coefficients exceeding 0.98 and slopes ranging from − 3.22 to − 3.56. PCR efficiencies ranged from 90.80% to 97.85%. Cycle threshold (Ct) values corresponding to 0.1% of the binary mixture were used as the cut-off values. Additionally, the specificity of the primer pairs was validated by analyzing 13 non-target plant species and assessed for practicality using 15 commercial samples. The developed primer pairs will aid in preventing the misidentification of toxic wild plants and serve to guide the identification of toxic species, thereby contributing to public health and safety.