Biology subjects

Vidalakis, G.

Publications and source records attributed to Vidalakis, G..

3 recordsLinked to original sources

bioRxiv2024

Rapid colorimetric detection of citrus tristeza virus combining portable sample preparation and reverse transcription-loop mediated isothermal amplification

AbstractsA sensing platform combining semi-automated sample preparation protocol and one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) is reported for rapid colorimetric detection of citrus tristeza virus (CTV) in a greenhouse. An OmniLyse micro-homogenizer and cellulose paper disks were integrated for quick sample preparation of total nucleic acids (<15 min). RT-LAMP assays were optimized in terms of primers concentrations and minimization of false positives for both CTV and cytochrome oxidase (COX) detections. Specifically, the optimal reaction time for lab-based RT-LAMP assays was determined as 40 minutes with the detection limits of CTV and COX as 43 copies/L (equivalent to 86 copies/mg of tissue) and 5 copies/L (equivalent to 10 copies/mg of tissue), respectively. Additionally, an in-greenhouse colorimetric RT-LAMP assay with lyophilized reaction mix for endpoint CTV detection was successfully conducted in 35 minutes without a false response in either colorimetric or fluorometric assays. Overall, this quick sample preparation protocol integrated with the lyophilized RT-LAMP assays showed high efficiency and reliability in plant pathogen detection in a greenhouse. This strategy holds great potential to be integrated into a portable, autonomous system and be universally adopted for in-field diagnosis of different pathogens.

bioengineering↗

bioRxiv2024

A 3D-printed handheld device for quick citrus tissue lysis and nucleic acid extraction

AbstractsA 3D-printed handheld device has been developed for rapid and efficient sample preparation from citrus leaves, aimed at streamlining protocols traditionally reliant on mortar and pestle. With its high-speed motor, knurled lysis chamber for rapid sample lysis, and quick nucleic acid extraction using paper disks, this device can yield ready-to-use extracts in just 12 minutes, significantly reducing the time required for sample preparation. The device was optimized for maximum sample lysis by evaluating operation voltages and chamber features. The results showed that the lysis chamber with internal knurling and the motor operated at 7.5 V was sufficient for effective sample lysis in 1 minute, achieving total RNA concentrations up to 87.6% of those obtained with a mortar and pestle. Furthermore, concerns regarding heat generation and resin release during the lysis process were found to not impact sample quality. To further facilitate in-field diagnosis, the capability of in-device sample preparation was verified with citrus sources infected with citrus tristeza virus and Spiroplasma citri in qPCR-based assays, where low assay variations were demonstrated (< 3.8%). Overall, the in-device sample preparation integrated with the paper disks showed good reliability and compatibility across different pathogens for downstream analysis. An eco-friendly sterilization protocol using household bleach and vitamin C solution was also developed to safely reuse the device for in-field deployment.

bioengineering↗

bioRxiv2022

Arbuscular mycorrhizal fungal composition across US citrus orchards, management strategies, and disease severity spectrum

Arbuscular mycorrhizal fungi (AMF) remain understudied in perennial cropping systems. Citrus is a globally grown fruit tree and under threat by the pandemic Huanglongbing (HLB) disease. Here, we assessed in what capacity geographical location, management strategies and disease affect AMF citrus root communities. Root samples were collected from 88 trees in ten orchards located in the two major citrus producing states in the US. Orchards were selected based on conventional or organic practices in California and based on HLB symptom severity in Florida. We used AMF-specific amplicon sequencing primers to capture community composition and diversity. Taxa names were assigned based on a phylogenetic analysis that comprised a backbone of AMF references sequences from Mycobank and virtual taxa from the MaarjAM database. AMF were detected in 78% of citrus root samples with taxa belonging to six known (Dominikia, Funneliformis, Glomus, Rhizophagus, Sclerocystis, Septoglomus) and unknown Glomeraceae genera. Geographical location affected AMF community composition but not richness, whereas management practice and disease influenced both richness and composition. Our approach indicated that perennial agroecosystems share a set of AMF generalist and specialist taxa. Some taxa could improve environmental fitness and be exploited for agricultural purposes.

microbiology↗