Zymoseptoria tritici causes Septoria leaf blotch of wheat. The prevailing paradigm of the Z. tritici-wheat interaction assumes fungal ingress through stomata within 24-48h, followed by days of symptomless infection. This is extrapolated from studies testing the mode of fungal ingress under optimal infection conditions. Here, we explicitly assess the timing of entry, using GFP-tagged Z. tritici. We show that early entry is comparatively rare, and extended epiphytic growth possible. We test the hypotheses that our data diverge from earlier studies due to: i. random ingress of Z. tritici into the leaf, with some early entry events; ii. previous reliance upon fungal stains, combined with poor attachment of Z. tritici to the leaf, leading to increased likelihood of observing internal versus external growth, compared to using GFP; iii. use of exceptionally high humidity to promote entry in previous studies. We combine computer simulation of leaf-surface growth with thousands of in planta observations to demonstrate that while spores germinate rapidly on the leaf, over 95% of fungi remain epiphytic, growing randomly over the leaf for ten days or more. We show that epiphytic fungi are easily detached from leaves by rinsing and that humidity promotes epiphytic growth, increasing infection rates. Together, these results explain why epiphytic growth has been dismissed and early ingress assumed. The prolonged epiphytic phase should inform studies of pathogenicity and virulence mutants, disease control strategies, and interpretation of the observed low in planta growth, metabolic quiescence and evasion of plant defences by Zymoseptoria during symptomless infection.

We present a high-quality draft genome assembly for Fusarium oxysporum f. sp. cubense tropical race 4 ( Fusarium odoratissimum ), assembled from PacBio reads and consisting of 15 contigs with a total assembly size of 48.59 Mb. This strain appears to belong to vegetative compatibility group complex 01213/16.

This pilot study investigated whether ambient biogenic volatile organic compounds (bVOCs)—scent profiles emitted by botanic glasshouse vegetation—could contribute to quantifiable human health and wellbeing outcomes. Over 11 months in 2024 (January–December), human participant trials were conducted at the Oxford Botanic Garden to compare the physiological and psychological effects associated with spending 30 min exposures in five different vegetation-rich glasshouses, each characterised by a distinct and complex bVOCs profile, with those of a plant-free room. Pre- and post-intervention assessments were conducted on 43 participants, using the State-Trait Anxiety Inventory (STAI), heart-beat rate (beats per minute), and heart rate variability (HRV): the latter two are widely used as an index of regulation of the autonomic nervous system. Significant reductions in STAI anxiety scores and decreases in heart-beat rate were observed, while HRV indices remained stable, relative to the plant-free room, following glasshouse exposure. Distinct scent profiles in the glasshouses included compounds that have previously shown associations with therapeutic effects in clinical settings, indicating the potential of these scented vegetation-rich glasshouse environments to promote the beneficial health effects observed in this study. Overall, these findings highlight the potential public health value of aromatic plant species and the importance of incorporating them into urban green space planning and policy.

Societal Impact Statement: As urbanisation accelerates globally, access to nature is increasingly recognised as vital for public health and wellbeing. We captured and analysed plant‐emitted airborne ‘scent signatures’ across Oxford's urban greenspaces to assess their potential health relevance. We found that sites differ in levels of health‐promoting volatiles and harmful pollutants and that these compounds vary with environmental conditions such as temperature and humidity. Our findings provide a novel framework for evaluating urban greenspaces, informing planning, air‐quality management and public health strategies to create greener, healthier cities. Summary: Biogenic volatile organic compounds (bVOCs) emitted by plants can promote stress reduction and cognitive benefits, whereas anthropogenic VOCs (aVOCs) common in urban air, such as BTEX compounds, pose health risks. We aimed to characterise and compare these airborne chemicals across urban greenspaces and develop a novel, health‐oriented metric for site evaluation. Air samples were collected across six Oxford greenspaces on a single date using Tenax™ filters and analysed by GC‐MS. Data were processed using metabolomics‐style workflows, identifying 245 biologically relevant compounds. Multivariate analyses compared site profiles, and one site was monitored over 12 months to assess environmental influences. Greenspaces exhibited significantly different volatile signatures, including variation in both health‐promoting bVOCs and harmful aVOCs. Temperature, humidity, wind speed and rainfall significantly influenced the presence and abundance of beneficial compounds. These results highlight the importance of considering airborne chemistry in urban planning and public health decision‐making. Integrating VOC profiling into planning and public health strategies could support delivery of higher‐quality, health‐promoting urban environments and inform guidance on optimal timing for outdoor activity.