Gene silencing of cathepsins B and L using CTV-based, plant-mediated RNAi interferes with ovarial development in Asian citrus psyllid (ACP), Diaphorina citri

Technological advances and the use of IoT in monitoring Diaphorina citri in citrus cultivation

The Asian citrus psyllid, Diaphorina citri, is a pest of great relevance to the citrus industry, acting as a vector for the bacterium Candidatus Liberibacter asiaticus (CLas), responsible for the disease known as Huanglongbing (HLB) or citrus greening. The distribution of D. citri covers tropical and subtropical regions, representing a significant threat to global citrus production and causing economic losses. Transmission of CLas occurs when the psyllid feeds on the phloem of citrus plants, spreading the disease severely. Therefore, the management of D. citri is essential for the health of citrus groves, and understanding its habitat and dispersal patterns is crucial for adequate control. Internet of Things (IoT) technology is a promising tool in agriculture, enabling real-time monitoring and control systems that increase the efficiency and sustainability of agricultural practices. The integration of IoT facilitates the early detection of D. citri and the continuous monitoring of their populations, improving the response to pest outbreaks and optimizing the use of insecticides. Systems based on AIoT (Artificial Intelligence of Things) and computer vision have demonstrated high accuracy in identifying and occurring pests, allowing for fast and efficient management. These technological advances, combined with biological strategies and traditional methods such as insecticides and physical traps, create a multifaceted approach to D. citri management. Integrating data from satellite images, field sensors, and machine learning algorithms makes developing more comprehensive and predictive monitoring of agricultural conditions possible. This helps mitigate the impacts of HLB and promotes more innovative, resilient farming practices. Smart agriculture, supported by IoT and technologies, offers a promising path to meet the challenges of modern agricultural production, combining real-time monitoring, innovative biological strategies, and predictive analytics to create a more sustainable and efficient agricultural system, essential to meet future challenges.

Identification and expression analysis of cathepsin B genes in Myzus persicae (Hemiptera: Aphididae) and their response to environmental stresses

Cathepsin B (CTSB) is a cysteine protease that is widely found in eukaryotes and plays a role in insect growth, development, digestion, metamorphosis, and immunity. In the present study, we examined the role of CTSB in response to environmental stresses in Myzus persicae Sulzer (Hemiptera: Aphididae). Six MpCTSB genes, namely MpCTSB-N, MpCTSB-16D1, MpCTSB-3098, MpCTSB-10270, MpCTSB-mp2, and MpCTSB-16, were identified and cloned from M. persicae. The putative proteins encoded by these genes contained three conserved active site residues, i.e. Cys, His, and Asn. A phylogenetic tree analysis revealed that the six MpCTSB proteins of M. persicae were highly homologous to other Hemipteran insects. Real-time polymerase chain reaction revealed that the MpCTSB genes were expressed at different stages of M. persicae and highly expressed in winged adults or first-instar nymphs. The expression of nearly all MpCTSB genes was significantly upregulated under different environmental stresses (38°C, 4°C, and ultraviolet-B). This study shows that MpCTSB plays an important role in the growth and development of M. persicae and its resistance to environmental stress.

Generation of Ext1 Gene-Edited Mice Model Via Dual sgRNAs/Cas9 System and Phenotypic Analyses

Hereditary multiple exostoses (HME) is an autosomal dominant skeletal disease. Genetic linkage analyses have identified that mutations in the exostosin glycosyltransferase (EXT)1 and EXT2 genes are linked to HME pathogenesis, with EXT1 mutation being the most frequent. The aim of this study was to generate a mice model with Ext1 gene editing to simulate human EXT1 mutation and investigate the genetic pathogenicity of Ext1 through phenotypic analyses. We designed a pair of dual sgRNAs targeting exon 1 of the mice Ext1 gene for precise deletion of a 46 bp DNA fragment, resulting in frameshift mutation of the Ext1 gene. The designed dual sgRNAs and Cas9 proteins were injected into mice zygotes cytoplasm. A total of 14 mice were obtained via embryo transfer, among which two genotypic chimera mice had a deletion of the 46 bp DNA fragment in exon 1 of the Ext1 gene. By hybridization and breeding, we successfully generated heterozygous mice with edited Ext1 gene (Ext+/-). Off-target effect analysis did not reveal off-target mutations in Ext+/- mice caused by the two sgRNAs used. Compared to wild-type mice, Ext+/- mice exhibited lower body weights. X-ray imaging showed hyperplastic bone near caudal vertebrae only in male Ext+/- mice, with computed tomography values approximately at 200 HU for hyperplastic bone between ribs and spine regions. Furthermore, immunohistochemical analysis revealed fewer articular chondrocytes expressing EXT1 in edited mice compared to wild-type ones. Pathological section analysis demonstrated no structural or morphological abnormalities in heart, liver, lung, or kidney tissues from Ext+/- mice. In conclusion, we successfully generated an accurate DNA deletion model for studying Ext1 using dual sgRNAs/Cas9 systems. In conclusion, we successfully generated precise DNA deletions in the Ext1 mice model using the dual sgRNAs/Cas9 system. In conclusion, we observed significant phenotypic changes in Ext+/- mice, particularly bone hyperplasia in male individuals; however, no exostosis was detected in the gene-edited mice. The introduction of a frameshift mutation into the Ext1 gene through CRISPR/Cas9 technology resulted in novel phenotypic alterations, highlighting the genetic pathogenicity of Ext1. Therefore, our Ext+/- mice serve as a valuable model for further biomedical investigations related to the Ext1 gene.

Host plant-induced changes in metabolism and osmotic regulation gene expression in Diaphorina citri adults

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a worldwide citrus pest. It transmits the pathogen Candidatus Liberibacter spp. of Huanglongbing (HLB), causing severe economic losses to the citrus industry. Severalgenera of plants in the Rutaceae family are the hosts of D. citri. However, the impact of these hosts on the metabolism and osmotic regulation gene expression of the pest remains unexplored. In this study, the contents of total sugars, sucrose, fructose, and glucose in young shoots, old leaves, and young leaves of 'Shatangju' mandarin and Murraya exotica were analyzed. Metabolomic analysis found that sucrose and trehalose were more abundant in the gut samples of D. citri adults fed on M. exotica when compared to what's in 'Shatangju' mandarin. A total of six aquaporin genes were identified in D. citri through the genome and transcriptome data. Subsequently, the expression patterns of these genes were investigated with respect to their developmental stage and tissue specificity. Additionally, the expression levels of osmotic regulation and trehalose metabolism genes in adults fed on different plants were evaluated. Our results provide useful information on the transfer of sugar between plants and D. citri. Our results preliminary revealed the sugar metabolism regulation mechanism in D. citri adults.