Plant Pathogen Detection Techniques: New Trends

Author: Prashanth Kumar A.

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Abstract

Plant infections are accountable for a significant proportion, around 40%, of the yearly decline in commercially valuable crops. This results in a substantial economic burden and has notable socio-ecological consequences. The primary objective of integrated pest management (IPM) is to mitigate the ecological consequences associated with conventional disease management approaches. This is achieved by the implementation of biological control methods and cultivation techniques that effectively minimize the occurrence of diseases or their associated symptoms. The present and developing techniques for detecting plant pathogens encompass cultivation-based, immunological, and nucleic acid-based approaches. Cultivation-based techniques encompass the deliberate cultivation and subsequent isolation of microorganisms using growth media that are either selective or semi-selective in nature. The aforementioned techniques are characterized by their simplicity, reliability, and lack of dependence on advanced technological apparatus. Nevertheless, these methods are deemed suboptimal as a result of their significant plate count anomaly, time-intensive procedures, and limited capability to identify viral plant diseases. Plant pathogens can be detected utilizing immunological techniques that involve the use of particular antibodies conjugated with enzymes, fluorophores, or nanoparticles. Nevertheless, it is important to acknowledge that these methodologies do possess several limitations, including the suboptimal chemical and physical stability of antibodies, the requirement for refrigeration during storage, and the challenges associated with generating new antibodies. Lateral flow immunoassays (LFIA) are commonly employed in the field of plant pathology for the purpose of detecting plant pathogens. However, it is important to note that these assays possess a restricted capacity for sample loading and are exclusively applicable to liquid samples. The utilization of aptamers as substitutes for antibodies in enzyme-linked apta-sorbent assays and lateral flow devices is feasible; nevertheless, it is important to note that the selectivity and affinity of aptamers can be affected by the circumstances of the sample. Conventional polymerase chain reaction (PCR) is a highly sensitive methodology; yet, it is not without limitations. These include susceptibility to PCR inhibitors, the necessity for a controlled laboratory setting, and an elevated potential for false-positive outcomes. A number of polymerase chain reaction (PCR) variants have been devised with the aim of enhancing the utility of PCR in the realm of plant pathogen identification. Isothermal nucleic acid amplification techniques present a valuable alternative to polymerase chain reaction (PCR)-based approaches. These techniques include loop-mediated isothermal amplification (LAMP), recombinase polymerase amplification (RPA), hybridization arrays, CRISPR-Cas-based molecular tools, and nucleic acid sequencing methods. Biosensors are intricate instruments that integrate a biorecognition component with a physicochemical transducer, enabling precise and timely identification of volatile organic compounds (VOCs) associated with plant diseases.

Keywords

Pathogens, enzymes, amplification, antibodies, PCR and biosensors

Conclusion

Plant diseases are responsible for causing a significant reduction in crop output, amounting to around 40% annually in economically significant crops. Consequently, the timely identification of these pathogens is of utmost importance for the implementation of integrated pest management strategies, the promotion of sustainable agricultural practices, and the reduction of reliance on chemical pesticides. Remote sensing technologies have the potential to aid in the identification and localization of stress conditions prior to the manifestation of apparent illness signs. The guidelines established by the National Plant Protection Organization (NPPO) encompass the implementation of PM7 Diagnostic Protocols for Regulated Pests. However, it is important to acknowledge that these protocols are subject to certain constraints, such as the requirement for specialized staff, the associated high costs, and the extended processing times involved. Various techniques, such as cultivation-based, immunological, PCR-based, isothermal amplification, hybridization-based, and next-generation sequencing, are now being developed to overcome these constraints. The selection of an optimal detection method is contingent upon various factors, including the specific pathogen being targeted, the allocated budget, the nature of the sample matrix, and the technological resources that are at one's disposal.

References

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How to cite this article

Prashanth Kumar A. (2023). Plant Pathogen Detection Techniques: New Trends. Biological Forum – An International Journal, 15(8a): 531-540.