Biology subjects

Zhang, H.-B.

Publications and source records attributed to Zhang, H.-B..

4 recordsLinked to original sources

bioRxiv2025

Lethal effects of phyllosphere fungi associated with local plants on invasive plant Ageratina adenophora seedlings

Native community resistance to plant invasion may reflect microbial effects on invader establishment. Here, we compared the effects of the aboveground and belowground microbes and leaf functional traits of 25 native plant species on the germination and survival of invader Ageratina adenophora. Results show that leaf physical and chemical traits vary among plant species and shape the aboveground microbial community. Local plants more phylogenetically close to A. adenophora harbour more similar pathogen communities to those A. adenophora. The aboveground tissue inoculations had more adverse effects on A. adenophora establishment by delaying germination time and decreasing the germination rate and seedling survival than did soil inoculations; aboveground tissues from local plants, which are more closely related to A. adenophora, cause longer germination times and greater seedling mortality of A. adenophora. Moreover, local plant aboveground fungi, rather than bacteria, adversely impact seedling survival, and most of the detrimental fungal pathogen ASVs are specialists. Several strains isolated from dead seedlings caused by aboveground tissue inoculations belonging to Alternaria, Fusarium and Stagonosporopsis were verified to kill more than 60% of A. adenophora seedlings and thus have great potential as biocontrol agents for A. adenophora. This is the first study to provide evidence for the effects of phylogenetic relatedness and leaf traits (both functional and microbial) on local community resistance to invaders through the regulation of germination and seedling survival.

ecology↗

bioRxiv2024

Distinct effects of phyllosphere and rhizosphere microbes on invader Ageratina adenophora during its early life stages

Microbes strongly affect invasive plant growth. However, how the phyllosphere and rhizosphere soil microbes distinctively affect seedling mortality and the growth of invasive plants across ontogeny under varying soil nutrient levels remains unclear. In this study, we used the invader Ageratina adenophora to evaluate these effects in plant growth chambers. We found that leaf litter harboured more potential pathogens and thus had more adverse effects on seed germination and seedling survival than soil inoculation. Microbial inoculation at different growth stages altered the microbial community and microbial functions of seedlings, and earlier inoculation had a more adverse effect on seedling survival and growth. In most cases, the soil nutrient level did not affect microbe-mediated seedling growth and the relative abundance of the microbial community and functions involved in seedling growth. The effects of some microbial genera on seedling survival are distinct from those on growth. Moreover, the A. adenophora seedling-killing effects of fungal strains isolated from dead seedlings by nonsterile leaf inoculation litter exhibited significant phylogenetic signals, by which strains of Allophoma and Alternaria generally caused high seedling mortality. Our study stresses the essential role of A. adenophora litter microbes in population establishment by regulating seedling density and growth.

plant biology↗

bioRxiv2020

Virulence evolution of multiple infections with vertically and horizontally transmitted fungal species in a natural plant system

The virulence evolution of multiple infections of parasites from the same species has been modelled widely in evolution theory, and the trajectories of evolution are relevant to parasite transmission mode, as well as to parasite and host population dynamics. However, experimental studies on this topic remain scarce, particularly regarding multiple infections by different parasite species. In this study, we employed the invasive plant Ageratina adenophora to verify the predictions made by the model. We observed that A. adenophora was a highly susceptible host to phylogenetically diverse foliar pathogens with mixed vertical and horizontal transmission within leaf spots. The pathogen community structure at the leaf spot level was determined by transmission mode. Over time, the pathogen community decreased in diversity; meanwhile, the vertically transmitted pathogens exhibited decreased virulence to the host A. adenophora, but the horizontally transmitted pathogens exhibited increased virulence to the host. Our results demonstrate that the predictions of classical models are still valid in a complex environment. Moreover, we propose that it is very important to determine whether the primary foliar pathogen of a given plant host is relevant to seedborne fungi, as this characteristic is an important factor in understanding pathogen-host interactions.

ecology↗

bioRxiv2019

Maize Kernel Development Stage the Primary Factor in Differential Gene Expression in Response to Two Methods of Field Inoculation with Aspergillus flavus

BackgroundAflatoxins, produced by the fungus Aspergillus flavus, often contaminate preharvest maize (Zea mays L.) grain under heat and drought stresses, posing serious health hazards to humans and livestock, and resulting in significant costs to identify and dispose of contaminated grain. This study was designed to investigate the changes in differential gene expression during seed morphogenesis and maturation in the \"aflatoxin resistant\" Argentinian inbred line Tx772 when challenged by the introduction of A. flavus through two different methods of ear inoculation; non-wounding (silk channel, used to select Tx772), wounding (side needle) and a non-inoculated control.\n\nMethod and FindingsGrain maturity had the largest effect on overall RNA-Seq differential gene expression (DGE) as measured by edgeR of the Bioconductor platform. However, within each stage of development, ranging from blister to dent, similar up-regulation in expression of many maize genes following inoculation with either method was observed; a total of 16 genes previously associated with resistance to pathogens were identified among the transcripts differentially expressed (DE) at p [≤] .05, FDR [≤] .10, and fold change [≥] 2.0 over all stages. The side needle technique produced a larger effect of infection as evidenced by 6,324 fungal reads versus 518 in silk channel and a higher level of aflatoxin. Correlations between approximately 7,000 fungal reads and the number of maize DE genes for each of the eight treatment groups was 0.56 (p = .152) and was 0.65 (p < .001) with levels of aflatoxin ranging from 0 to 137 ng g-1.\n\nConclusionThese correlations provided an internal measure of effectiveness of inoculation methods that were associated with the mostly up-regulation of defense-related genes in response to the presence of Aspergillus flavus in a unique maize genetic background.

plant biology↗