Analysis of the Distribution Pattern of Phenacoccus manihoti in China under Climate Change Based on the Biomod2 Model.

The changing global climate has significantly impacted the spread of plant pests. The cassava mealybug (Phenacoccus manihoti) is among the most dangerous quarantine pests affecting cassavas worldwide, causing substantial losses in agricultural production and food security across several regions. Although China is currently free of the cassava mealybug, its proximity to affected countries and extensive trade with these regions necessitate a detailed understanding of the pest's distribution pattern and dynamic ecological niche changes. Using the Biomod2 model, we selected two historical climate scenarios and two future climate scenarios (SSP1-2.6 and SSP5-8.5) to investigate the distribution patterns, potential habitats, distribution centers, and dynamic ecological niches of cassava mealybugs in China. Key environmental variables influencing the distribution were identified, including bio4, bio8, bio12, bio18, and bio19. The potential habitat of cassava mealybugs is mainly located in several provinces in southern China. In the future, the suitable habitat is projected to expand slightly under the influence of climate change, maintaining the overall trend, but the distribution center of suitable areas will shift northward. Dynamic ecological niche prediction results indicate the potential for further expansion; however, the ecological niches may be unequal and dissimilar in the invaded areas. The predictions could serve as a valuable reference for early warning systems and management strategies to control the introduction of cassava mealybugs.

Genome-Wide Characterization of the Phenylalanine Ammonia-Lyase Gene Family and Their Potential Roles in Response to Aspergillus flavus L. Infection in Cultivated Peanut (Arachis hypogaea L.).

Phenylalanine ammonia-lyase (PAL) is an essential enzyme in the phenylpropanoid pathway, in which numerous aromatic intermediate metabolites play significant roles in plant growth, adaptation, and disease resistance. Cultivated peanuts are highly susceptible to Aspergillus flavus L. infection. Although PAL genes have been characterized in various major crops, no systematic studies have been conducted in cultivated peanuts, especially in response to A. flavus infection. In the present study, a systematic genome-wide analysis was conducted to identify PAL genes in the Arachis hypogaea L. genome. Ten AhPAL genes were distributed unevenly on nine A. hypogaea chromosomes. Based on phylogenetic analysis, the AhPAL proteins were classified into three groups. Structural and conserved motif analysis of PAL genes in A. hypogaea revealed that all peanut PAL genes contained one intron and ten motifs in the conserved domains. Furthermore, synteny analysis indicated that the ten AhPAL genes could be categorized into five pairs and that each AhPAL gene had a homologous gene in the wild-type peanut. Cis-element analysis revealed that the promoter region of the AhPAL gene family was rich in stress- and hormone-related elements. Expression analysis indicated that genes from Group I (AhPAL1 and AhPAL2), which had large number of ABRE, WUN, and ARE elements in the promoter, played a strong role in response to A. flavus stress.

Efficacy of a live attenuated highly pathogenic PRRSV vaccine against a NADC30-like strain challenge: implications for ADE of PRRSV.

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) infection can cause severe reproductive failure in sows and respiratory distress in pigs of all ages, leading to major economic losses. To date, there are still no effective strategies to prevent and control PRRSV. Antibody-dependent enhancement (ADE), a phenomenon in which preexisting non-neutralizing antibodies or sub-neutralizing antibodies facilitate virus entry and replication, may be a significant obstacle in the development of effective vaccines for many viruses, including PRRSV. However, the contribution of ADE to PRRSV infection remains controversial, especially in vivo. Whether attenuated PRRSV vaccines prevent or worsen subsequent disease in pigs infected by novel PRRSV strains requires more research. In the present study, in vivo experiments were conducted to evaluate ADE under different immune statuses, which were produced by waiting different lengths of time after vaccination with a commercially available attenuated highly pathogenic PRRSV (HP-PRRSV) vaccine (JXA1-R) before challenging the pigs with a novel heterologous NADC30-like strain. RESULTS: Piglets that were vaccinated before being challenged with PRRSV exhibited lower mortality rates, lower body temperatures, higher bodyweight gain, and lower viremia. These results demonstrate that vaccination with JXA1-R alleviated the clinical signs of PRRSV infection in all vaccinated groups. CONCLUSIONS: The obtained data indicate that the attenuated vaccine test here provided partial protection against the NADC30-like strain HNhx. No signs of enhanced PRRSV infection were observed under the applied experimental conditions. Our results provide some insight into the molecular mechanisms underlying vaccine-induced protection or enhancement in PRRSV.