Plant pathogenesis: Toward multidimensional understanding of the microbiome

Abstract Single pathogen‐targeted disease management measure has shown drawbacks in field efficacy under the scenario of global change. An in‐depth understanding of plant pathogenesis will provide a promising solution but faces the challenges of the emerging paradigm involving the plant microbiome. While the beneficial impact of the plant microbiome is well characterized, their potential role in facilitating pathological processes has so far remained largely overlooked. To address these unsolved controversies and emerging challenges, we hereby highlight the pathobiome, the disease‐assisting portion hidden in the plant microbiome, in the plant pathogenesis paradigm. We review the detrimental actions mediated by the pathobiome at multiple scales and further discuss how natural and human triggers result in the prevalence of the plant pathobiome, which would probably provide a clue to the mitigation of plant disease epidemics. Collectively, the article would advance the current insight into plant pathogenesis and also pave a new way to cope with the upward trends of plant disease by designing the pathobiome‐targeted measure

Seasonal Variation in the Thermal Environment and Health-Related Factors in Two Clustered Recreational Bamboo Forests

Forest thermal environments and health-related factors have a significant impact on user experience and physical benefits. Therefore, it is important to study changes in the thermal environment and health-related factors in recreational forests. Clustered bamboo forests have unique structures featuring high canopy density and extensive understory spaces suitable for recreational activities. However, there is no relevant report on the recreational use of these forests. This study investigated seasonal characteristics in the thermal comfort and health-related factors in two clustered bamboo forests in Southwest China. Microenvironmental parameters and health-related factors (negative air oxygen ions (NAI), airborne particulate matter, airborne microorganisms, and biogenic volatile organic compounds (BVOCs)) were measured in four seasons. The microenvironmental parameters were converted into a physiological equivalent temperature (PET) for each period. The results showed that (1) most of the time, the thermal comfort, air particle, NAI, and bacteria concentrations in the two bamboo forests were superior to the controls and met the standard for recreational activities; (2) thermal comfort environments and health-related factors levels varied between two bamboo forests; and (3) the most abundant compounds in the two bamboo forests in each season were leaf alcohol and 2-hexenal. The two clustered bamboo forests provided a comfortable thermal environment and had clean air and bactericidal abilities in all seasons. The forests emitted BVOCs with fresh grass and leaf fragrances, helping to alleviate the sense of depression among visitors. The results confirm that clustered bamboo forests can provide suitable recreational conditions. The results can be used to guide the management of recreational forests and provide support for the development of bamboo forests

Screening and functional verification of the target protein of pedunsaponin A in the killing of Pomacea canaliculata

Previous study found that pedunsaponin A (PA) influenced the cytoskeleton of Pomacea canaliculata hemocytes, leading to depolarization and haemocyte destruction and eventually to snail death. In this study, we analysed the changes in protein expression by iTRAQ-mediated proteomics and identified 51 downregulated proteins. Among these, we focused on proteins related to cytoskeletal function and identified neural Wiskott-Aldrich syndrome isoform X1 (PcnWAS). The full-length PcnWAS gene contains 9791 bp and includes an open reading frame of 1401 bp that encodes 735 amino acids with a predicted molecular mass of 49.83 kD. PcnWAS exhibited a relatively distant genetic relationship with known species; the closest homologue is Biomphalaria glabrata (57%). RNA interference (RNAi) was adopted to verify the function of PcnWAS after screening the siRNA sequence with an efficiency of 97%. Interference with the gene expression of PcnWAS did not lead to snail death, but the depolarization level increased, which demonstrated that PcnWAS is an important depolarization-related protein. The results of PA treatment of snails subjected to RNAi proved that interfering with PcnWAS gene expression decreased the molluscicidal activity of PA toward P. canaliculata; snail mortality after RNAi was significantly lower (40%) than that in PA-treated snails without RNAi (54%), while the survival rate and depolarization level in haemocytes were not significant, indicating that PcnWAS is only one of the important target proteins of PA in P. canaliculata. This study lays the foundation for further exploration of the molecular mechanism by which PA kills this harmful snail

The Damaging Effects of Pedunsaponin A on Pomacea canaliculata Hemocytes

Pomacea canaliculata hemocytes are the main functional cells in the immune defense system, and hemocyte destruction disrupts the immune response mechanism of P. canaliculata, resulting in abnormal growth, development, reproduction, and even death. Our previous study found that Pedunsaponin A significantly affects P. canaliculata hemocyte structure. This study further investigated the damaging effects of Pedunsaponin A on P. canaliculata hemocytes. The cell mortality rate results showed that the hemocyte mortality was significantly increased after treatment with Pedunsaponin A, and the mortality rate exhibited a significant positive correlation with treatment time and dose. The membrane potential results showed that the cell membranes of P. canaliculata hemocytes exhibited time-dependent membrane depolarization after 40 mg/L Pedunsaponin A treatment. At 36 h, the cell depolarization rate in the Pedunsaponin A treatment group was 41.43%, which was significantly greater than the control group (6.24%). The cytoskeleton results showed that Pedunsaponin A led to disordered and dispersed arrangement of microfilaments and changes in the cytoskeletal structure. The apoptosis and cell cycle results showed that Pedunsaponin A induced apoptosis and influenced the cell cycle to some extent. These results showed that the cell membrane and cytoskeleton of P. canaliculata hemocytes were damaged after treatment with Pedunsaponin A, which led to an increase in cell mortality, dysfunction, cell cycle abnormalities and apoptosis. This study provides a foundation for further identification of the site of Pedunsaponin A activity on hemocytes

A new vaccination regimen using adenovirus-vectored vaccine confers effective protection against African swine fever virus in swine

ABSTRACTAfrican swine fever (ASF) is an acute and highly contagious lethal infectious disease in swine that severely threatens the global pig industry. At present, a safe and efficacious vaccine is urgently required to prevent and control the disease. In this study, we evaluated the safety and immunogenicity of replication-incompetent type-2 adenoviruses carrying African swine fever virus (ASFV) antigens, namely CP204L (p30), E183L (p54), EP402R (CD2v), B646L (p72), and B602L (p72 chaperone). A vaccine cocktail delivered by simultaneous intramuscular (IM) and intranasal (IN) administration robustly elicited both systemic and mucosal immune responses against AFSV in mice and swine and provided highly effective protection against the circulating ASFV strain in farmed pigs. This multi-antigen cocktail vaccine was well tolerated in the vaccinated animals. No significant interference among antigens was observed. The combined IM and IN vaccination using this adenovirus-vectored antigen cocktail vaccine warrants further evaluation for providing safe and effective protection against ASFV infection and transmission