
Leaf litter microbes have more adverse effects on seed germination and seedling survival of the invasive plant Ageratina adenophora compared to soil microbes, especially during the early growth stage.


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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.

### Competing Interest Statement

The authors have declared no competing interest.

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

leaf-litter-microbes-significantly-reduce-seedling-survival-of-the-invasive-plant-ageratina-adenophora


Leaf Litter Microbes Significantly Reduce Seedling Survival of the Invasive Plant Ageratina adenophora


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Tight regulation of programmed cell death and rapid clearance of dead root cap cells is essential to restrict fungal colonization, especially in the root meristematic zone. Beneficial fungi can manipulate host programmed cell death pathways, such as by downregulating the senescence-associated nuclease BFN1, to facilitate their accommodation in the root differentiation zone.


Programmed cell death occurring during plant development (dPCD) is a fundamental process integral for plant growth and reproduction. Here, we investigate the connection between developmentally controlled PCD and fungal accommodation in Arabidopsis thaliana roots, focusing on the root cap-specific transcription factor ANAC033/SOMBRERO (SMB) and the senescence-associated nuclease BFN1. Mutations of both dPCD regulators increase colonization by the beneficial fungus Serendipita indica , primarily in the differentiation zone. smb-3 mutants additionally exhibit hypercolonization around the meristematic zone and a delay of S. indica -induced root-growth promotion. This demonstrates that root cap dPCD and rapid post-mortem clearance of cellular corpses represent a physical defense mechanism restricting microbial invasion of the root. Additionally, reporter lines and transcriptional analysis revealed that BFN1 expression is downregulated during S. indica colonization in mature root epidermal cells, suggesting transcriptional control as a means for microbial regulation of host dPCD.



### Competing Interest Statement

The authors have declared no competing interest.

Root cap cell corpse clearance limits microbial colonization in Arabidopsis thaliana

programmed-cell-death-in-root-development-regulates-fungal-colonization-in-arabidopsis


Programmed Cell Death in Root Development Regulates Fungal Colonization in Arabidopsis
