Biology subjects

Waller, S.

Publications and source records attributed to Waller, S..

3 recordsLinked to original sources

bioRxiv2026

The RNA virome of intertidal kelp in New Zealand reveals novel viral lineages associated with unhealthy kelp

Pathogens can have major impacts on ecosystem function, especially when they infect foundational taxa such as habitat-forming kelp. Understanding which potentially pathogenic microbes are in an ecosystem is increasingly important as environmental change intensifies ecosystem imbalances, yet few studies have examined which viruses are associated with key habitat-forming macroalgae. Here, we screened multiple populations of intertidal / shallow-subtidal macroalgae in New Zealand for viruses. Samples were collected from three southern bull kelp species: Durvillaea antarctica, Durvillaea poha and Durvillaea willana. Total RNA was extracted and sequenced from both obviously unhealthy kelp tissue and apparently healthy tissue. We identified several novel viruses belonging to the families Mitoviridae, Narnaviridae, Partitiviridae, Totiviridae, and the recently proposed Ormycovirus group. Viral abundance and diversity were notably higher at Lawyers Head (the site closest to a city) compared to other sites, especially in unhealthy kelp samples. The elevated viral presence at Lawyers Head may indicate that human impacts, such as pollution, are influencing viral prevalence. This study reveals that coastal macroalgae in New Zealand host diverse viral lineages, some likely pathogenic, and hints at the potential influence of anthropogenic pollution on marine virome composition.

microbiology↗

bioRxiv2025

Viral surveillance of invasive mammals in New Zealand reveals unique viral lineages reflecting their introduction history

Introduced mammalian species in Aotearoa New Zealand pose significant ecological risks and may serve as reservoirs for novel or emerging infectious diseases. In this study, we present the first metatranscriptomic survey of viruses in five introduced mammals: ferrets (Mustela furo), stoats (Mustela erminea), weasels (Mustela nivalis), brushtail possums (Trichosurus vulpecula), and European hedgehogs (Erinaceus europaeus), sampled across both the North and South Islands. Through total RNA sequencing, we identified 11 mammalian-infecting viruses spanning eight viral families, including four novel virus species: Ferret mastadenovirus, Possum astrovirus, Ferret pestivirus, and Weasel jeilongvirus. Whole genomes were recovered for six of these viruses, enabling detailed phylogenetic analysis. Notably, we observed strong global geographic clustering in both Wobbly possum disease virus and Ferret hepatitis E virus, suggesting localized viral evolution following the introduction of their hosts into New Zealand. In addition, the detection of Human rotavirus A in hedgehogs highlights the possibility of reverse zoonotic transmission. Together, these findings broaden our understanding of the viral diversity harboured by New Zealands introduced mammals and provide a critical foundation for future biocontrol and disease surveillance ehorts. IMPORTANCEIntroduced mammals in Aotearoa New Zealand not only threaten native biodiversity through predation and competition, but also represent a largely overlooked source of infectious disease risk. Viruses circulating in these species may spill over into native wildlife, livestock, or even humans, while human viruses can also establish in introduced animals and create new reservoirs. Understanding which viruses are present, and how they evolve in isolated host populations, is critical for anticipating future disease outbreaks, improving biosecurity, and guiding wildlife management strategies. This work provides foundational knowledge that links ecology, conservation, and health, highlighting the need to consider pathogens as part of the broader impact of invasive species.

microbiology↗

bioRxiv2022

Smoke exposed roots causes reduced whole-plant vascular sectoriality.

While photosynthates are partitioned by the relative strength of young developing leaves and roots as sinks for carbon-based resources, many plants also show a close relationship between partitioning, phyllotaxy and vascular connectivity, yielding sectorial patterns of allocation. We examined whether smoke influences phloem vascular sectoriality in a model plant, sunflower (Helianthis annuus L.). Using radioactive 11CO2 administered to single photosynthetically active source leaves, we examined the transport behavior and allocation patterns of 11C-photosynthates using gamma counting and autoradiography. Soil treated with liquid smoke caused significant reductions in phloem sectoriality involving young sink leaves and roots. The resulting increase in vascular connectivity could benefit young plant performance by allowing a more uniform allocation of nutrients and/or stress signal molecules at a critical time of their growth. One-Sentence SummarySmoke-exposed roots exhibit a significant reduction in phloem sectoriality involving carbon transport to young sink leaves and roots.

physiology↗