A reverse transcription-cross-priming amplification method with lateral flow dipstick assay for the rapid detection of Bean pod mottle virus

Isothermal Nucleic Acid Amplification-Based Lateral Flow Testing for the Detection of Plant Viruses

Isothermal nucleic acid amplification-based lateral flow testing (INAA-LFT) has emerged as a robust technique for on-site pathogen detection, providing a visible indication of pathogen nucleic acid amplification that rivals or even surpasses the sensitivity of real-time quantitative PCR. The isothermal nature of INAA-LFT ensures consistent conditions for nucleic acid amplification, establishing it as a crucial technology for rapid on-site pathogen detection. However, despite its considerable promise, the widespread application of isothermal INAA amplification-based lateral flow testing faces several challenges. This review provides an overview of the INAA-LFT procedure, highlighting its advancements in detecting plant viruses. Moreover, the review underscores the imperative of addressing the existing limitations and emphasizes ongoing research efforts dedicated to enhancing the applicability and performance of this technology in the realm of rapid on-site testing.

Microfluidic Device for Simple Diagnosis of Plant Growth Condition by Detecting miRNAs from Filtered Plant Extracts

Plants are exposed to a variety of environmental stress, and starvation of inorganic phosphorus can be a major constraint in crop production. In plants, in response to phosphate deficiency in soil, miR399, a type of microRNA (miRNA), is up-regulated. By detecting miR399, the early diagnosis of phosphorus deficiency stress in plants can be accomplished. However, general miRNA detection methods require complicated experimental manipulations. Therefore, simple and rapid miRNA detection methods are required for early plant nutritional diagnosis. For the simple detection of miR399, microfluidic technology is suitable for point-of-care applications because of its ability to detect target molecules in small amounts in a short time and with simple manipulation. In this study, we developed a microfluidic device to detect miRNAs from filtered plant extracts for the easy diagnosis of plant growth conditions. To fabricate the microfluidic device, verification of the amine-terminated glass as the basis of the device and the DNA probe immobilization method on the glass was conducted. In this device, the target miRNAs were detected by fluorescence of sandwich hybridization in a microfluidic channel. For plant stress diagnostics using a microfluidic device, we developed a protocol for miRNA detection by validating the sample preparation buffer, filtering, and signal amplification. Using this system, endogenous sly-miR399 in tomatoes, which is expressed in response to phosphorus deficiency, was detected before the appearance of stress symptoms. This early diagnosis system of plant growth conditions has a potential to improve food production and sustainability through cultivation management.

Plant Virus Sensor for the Rapid Detection of Bean Pod Mottle Virus Using Virus-Specific Nanocavities

This study presents a miniaturized sensor for rapid, selective, and sensitive detection of bean pod mottle virus (BPMV) in soybean plants. The sensor employs molecularly imprinted polymer technology to generate BPMV-specific nanocavities in porous polypyrrole. Leveraging the porous structure, high surface reactivity, and electron transfer properties of polypyrrole, the sensor achieves a sensitivity of 143 μA ng-1 mL cm-2, a concentration range of 0.01-100,000 ng/mL, a detection time of less than 2 min, and a detection limit of 41 pg/mL. These capabilities outperform those of conventional methods, such as enzyme-linked immunosorbent assays and reverse transcription polymerase chain reactions. The sensor possesses the ability to distinguish BPMV-infected soybean plants from noninfected ones while rapidly quantifying virus levels. Moreover, it can reveal the spatial distribution of virus concentration across distinct leaves, a capability not previously attained by cost-effective sensors for such detailed viral data within a plant. The BPMV-specific nanocavities can also be easily restored and reactivated for multiple uses through a simple wash with acetic acid. While MIP-based sensors for plant virus detection have been relatively understudied, our findings demonstrate their potential as portable, on-site diagnostic tools that avoid complex and time-consuming sample preparation procedures. This advancement addresses a critical need in plant virology, enhancing the detection and management of plant viral diseases.

Detection of Tomato Ringspot Virus Based on Microfluidic Impedance Sensor

A microfluidic impedance sensor embedded with gold interdigitated array microelectrodes was utilized to rapidly detect Tomato Ringspot Virus (ToRSV) and achieve efficient and precise detection. The electrochemical impedance spectrum was obtained by immobilizing ToRSV antibody on the surface of a gold interdigital array microelectrode and mixing it with ToRSV to generate an impedance change. The electrochemical impedance spectrum was obtained. The equivalent circuit was established to analyze the mechanism of impedance change, and the quantitative linear relationship between ToRSV concentration and impedance was established. According to an equivalent circuit analysis, ToRSV increases the solution resistance Rs, the electron transfer resistance Ret on the electrode surface, and the double layer capacitance Cdl, resulting in an increase in impedance. The results reveal that the ToRSV concentration detected in the range of 0.001 to 10 μg/mL ranges from 248.8 to 687.2 kΩ at the ideal detection frequency of 10.7 Hz, with a good linear connection, R² = 0.98. When this method's detection limit is tested, the impedance value is 367.68 kΩ. 0.0032 μg/mL was the detection limit. The sensor is quick and easy to use, has high detection sensitivity, and can be used to detect other plant viruses.