Expanding research and development of functional nucleic acids for agricultural applications

As an essential class of macromolecules in biological systems,nucleic acids continue to surprise many as more and more biological and nonbiological functions of nucleic acids are revealed and increasingly diverse applications of nucleic acids are demonstrated.A hotly pursued research area for the past 50 years is“functional nucleic acids”,natural or synthetic nucleic acid molecules that possess catalytic activity(nucleic acid enzymes),binding properties(nucleic acid aptamers),or both functions(aptazymes).Thomas Cech and Sidney Alterman were the first two scientists who made ground-breaking discoveries of unexpected properties of nucleic acids in early 1980s–their catalytic abilities–through the findings that some naturally occurring single-stranded RNA molecules,termed ribozymes,exhibit catalytic activities.1,2 This was followed by the demonstration of an experimental method in 1990,known as in vitro selection or SELEX,3,4 that allows the isolation of single-stranded nucleic acid molecules with either catalytic or binding properties.The development of this test-tube selection and evolution method has permitted rapid development of RNA aptamers(target-recognizing RNA molecules),DNA aptamers(target-binding DNA molecules),artificial ribozymes,and DNAzymes(enzymes made of DNA).Since then,thousands of aptamers have been discovered for diverse targets that include small molecules,proteins,viruses and bacteria.5 Similarly,many artificial ribozymes and DNAzymes have been discovered to catalyze diverse chemical reactions.6 Ribozymes or DNAzymes can be further combined with aptamers to create allosteric ribozymes or DNAzymes,which sometimes are simply referred to as aptazymes.All these functional nucleic acids have found increasingly diverse applications as biosensors,diagnostics,imaging agents,and therapeutics,applications in research and development areas that humans care a lot about,such as healthcare sector,environmental protection,agricultural production and food safety.6–8 As a co-editor-in-chief for our new journal Advanced Agrochem,I am motivated to get more people interested in exploring functional nucleic acids to solve problems faced in the agriculture sector.

Functional nucleic acid-based biosensors for virus detection

A growing number of viruses pose significant threats to human health,impact agricultural production and compromise food safety.Minimizing the impact of viral infections demands for effective technologies that can deliver sensitive viral detection under various settings.Functional nucleic acids(FNAs)–natural or synthetic nucleic acid molecules with catalytic and/or binding properties–have been increasingly explored as key components for setting up diagnostic tests for viral detection.FNA-based viral biosensors offer distinct advantages,such as the ability to achieve sensitive viral detection in complex biological samples,ease of use,scalability,and cost-effectiveness.This mini-review will be dedicated to appraising progress made in recent years in FNA-based biosensors for diagnosing diverse human and animal viruses.We will first describe virus structures and potential biomarkers that can be utilized as the targets for FNA probe engineering.This is followed by reviewing the latest advances in two classes of FNAs-DNAzyme and DNA aptamers,with focuses on DNAzyme-and DNA aptamerbased biosensors that employ diverse signal transduction mechanisms to achieve sensitive viral detections.Finally,we will discuss current challenges in the field and suggest future research directions that can address these challenges.