field-deployable-candidatus-liberibacter-asiaticus-detection-using

Field-Deployable <em>Candidatus</em> Liberibacter asiaticus Detection Using Recombinase Polymerase Amplification Combined with CRISPR-Cas12a

The early detection of Candidatus Liberibacter asiaticus (CLas) by citrus growers facilitates early intervention and prevents the spread of disease. A ...

Gannan Normal University

Larvae of click beetles are the most important soil-dwelling agricultural pests and are abundant throughout the world.  sp. belongs to the subfamily Agrypninae of Elateridae. Here, we sequenced and annotated the complete mitochondrial genome (mitogenome) of  sp., the new representative of the mitogenome of the subfamily. This mitogenome was 16,056 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and two ribosomal RNA unit genes (rRNAs). Gene order was conserved and identical to most other previously sequenced Elateridae. The nucleotide composition biases towards A and T, which together made up 70.8% of the entirety. Phylogenetic analysis based on 13 PCGs sequences showed that  sp. got together with the same subfamily species , , , and  with high support value.

The complete mitochondrial genome of click beetle  sp. (Coleoptera: Elateridae) and phylogenetic analysis.

 subsp.  () is the causal agent of citrus bacterial canker (CBC), one of the most devastating citrus diseases. Most commercial citrus varieties are susceptible to CBC. However, some citrus varieties and wild citrus germplasms are CBC resistant and are promising in genetic increases in citrus resistance against CBC. We aimed to evaluate citrus germplasms for resistance against CBC. First, we developed a rapid evaluation method based on enhanced yellow fluorescent protein (eYFP)-labeled . The results demonstrated that eYFP does not affect the growth and virulence of .  allows measurement of bacterial titers but is more efficient and rapid than the plate colony counting method. Next, we evaluated citrus germplasms collected in China. Based on symptoms and bacterial titers, we identified that two citrus germplasms ('Ichang' papeda and 'Huapi' kumquat) are resistant, whereas eight citrus germplasms ('Chongyi' wild mandarin, 'Mangshan' wild mandarin, 'Ledong' kumquat, 'Dali' citron, 'Yiliang' citron, 'Longyan' kumquat, 'Bawang' kumquat, and 'Daoxian' wild mandarin) are tolerant. In summary, we have developed a rapid evaluation method to test the resistance of citrus plants against CBC. This method was successfully used to identify two highly canker-resistant citrus germplasms and eight citrus germplasms with canker tolerance. These results could be leveraged in traditional breeding contexts or be used to identify canker resistance genes to increase the disease resistance of commercial citrus varieties via biotechnological approaches.

Rapid Evaluation of the Resistance of Citrus Germplasms Against  subsp. .

 subsp.  () is the agent of citrus bacterial canker (CBC) disease, which has significantly reduced citrus quantity and quality in many producing areas worldwide. Copper-based bactericides are the primary products for CBC control and management, but the problems derived from copper-resistant and environmental contamination have become issues of anxiety. Thus, there is a need to find alternative antibacterial products instead of relying on a single type of agent. This study developed a method to evaluate the inhibition of antibacterial agents using the fluorescence-labeled recombinant  strain (). The optimization of timelines and parameters for the evaluation of antibacterial agents involved the use of a Spark™ multimode microplate reader. This evaluation and screening method can be applied to bactericides, cocktail-mixture formulations, antagonistic bacteria, and derived metabolites. The results showed that the minimum inhibitory concentration (MIC) of commercial bactericides determined by fluorescence agrees with the MIC values determined by the conventional method. A screened cocktail-mixture bactericide presents more activity than the individual agents during the protective effects. Notably, this method has been further developed in the screening of -antagonistic bacterial strains. In summary, we provide a validated strategy for screening and evaluation of different antibacterial components for inhibition against  for CBC control and management.

Yunfei Long

China-USA Citrus Huanglongbing Joint Laboratory,
National Navel Orange Engineering Research Center,
China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center

Gannan Normal University

Field-Deployable Candidatus Liberibacter asiaticus Detection Using Recombinase Polymerase Amplification Combined with CRISPR-Cas12a

Yunfei Long

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}China-USA Citrus Huanglongbing Joint Laboratory,National Navel Orange Engineering Research Center,China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center

Gannan Normal University

Field-Deployable Candidatus Liberibacter asiaticus Detection Using Recombinase Polymerase Amplification Combined with CRISPR-Cas12a

China-USA Citrus Huanglongbing Joint Laboratory,
National Navel Orange Engineering Research Center,
China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center