Robigalia Roundup LXXXI: Nature Portfolio wants your plant disease research

Hello {{first_name | Robigalia readers}},

If you're anything like me, you probably have a few publications on the backburner at the moment. If you're in need of some motivation to get those manuscripts done, there have been two calls for papers in recent weeks from journals covering different corners of our field.

Molecular Plant-Microbe Interactions has a focus issue in the works: "Plant Immune Receptors in the Spotlight", with a deadline of 31 October 2026. The issue covers the full breadth of immune receptor biology, from PRRs and NLRs through to newer classes like receptor-like proteins and tandem kinase proteins. Molecular, structural, evolutionary, and network-level approaches are all welcome, as are studies with translational potential. All MPMI content is open access, and focus issues get strong promotion given their single-topic framing.

Scientific Reports (Nature Portfolio) has a Collection open on “spatial omics in plant diseases”, accepting submissions until January 2027. It covers multi-omics approaches applied to disease management, including spatial genomics, transcriptomics, metabolomics, and proteomics. Narrative reviews are also welcome, directed to the sister journal Scientific Reviews.

Now, onto this week’s edition:

Let’s dive in!

We tend to think of emerging plant diseases as a consequence of pathogen movement, a fungus or bacterium hitching a ride on traded commodities into a region where it has never been before. A paper by Crouch et al., published in PNAS, makes the case that the reverse process is equally important: introducing crops into regions where native pathogens already exist on related wild hosts can be just as consequential for disease emergence.

The authors reconstruct the global evolutionary history of powdery mildews infecting strawberries and raspberries, long attributed to a single cosmopolitan species, Podosphaera aphanis. Using multilocus phylogenetics, haplotype networks, and molecular clock dating applied to both fresh specimens and herbarium material spanning over a century, they show the group comprises at least four distinct taxa: Podosphaera fragariae on Eurasian strawberries, Podosphaera shepherdiae on North American strawberries, and separate raspberry-infecting lineages with similarly strong ties to their host geography. Divergence times place these lineages well before modern agriculture, with strawberry-infecting species separating around 5.8 million years ago and raspberry-infecting lineages diverging roughly 240,000 years ago.

Podosphaera shepherdiae was found on native Shepherdia argentea and Glossopetalon spinescens in herbarium specimens from the early 1900s, predating or coinciding with the earliest records of strawberry powdery mildew in North America. The pathogen was already there; the introduced crop provided a new host.

This pattern appears elsewhere. Austropuccinia psidii devastated eucalypt plantations introduced into South America, where the rust had long persisted on native myrtaceous hosts. In Australia, introduced citrus has been exploited by the native citrus gall wasp, Bruchophagus fellis, a pest that coexisted with native finger lime hosts long before commercial orchards arrived. The findings also highlight the value of herbarium collections and native host sampling in tracing pathogen origins, both of which remain underused in studies of agricultural disease.

When Japanese farmers first encountered a new stunting disease in their rice fields in the early 1950s, they were witnessing the formal description of a virus that would go on to reshape cereal pathology across East Asia. Rice black-streaked dwarf virus (RBSDV) was first reported in 1952 by Kuribayashi and Shinkai, but its most damaging outbreaks were still to come, with major epidemics in Japan, China, and Korea across the 1960s and again from the 1990s onwards.

Rice black-streaked dwarf virus belongs to the genus Fijivirus within the family Spinareoviridae. Its genome consists of ten segments of linear double-stranded RNA, packaged in icosahedral two-layered particles approximately 75–80 nm in diameter. The virus is transmitted exclusively by the small brown planthopper (Laodelphax striatellus) in a persistent, circulative, and propagative manner, meaning the virus replicates within the insect vector as well as in the plant host. No other means of transmission in nature has been confirmed, which makes vector population dynamics central to understanding why epidemics are so unpredictable.

The host range extends across economically important Poaceae, including rice, maize, wheat, and barley. In susceptible japonica rice, the symptoms are distinctive: severe stunting, darkening and twisting of leaves, and white waxy enations along the veins on the undersides of leaf blades, sheaths, and stems. Affected plants produce deformed or barren panicles, and while they often survive to harvest, yield components including panicle length, spikelet number, and grain weight are all significantly reduced. Maize infected by RBSDV presents similarly, with stunting and rough white streaks along leaf veins, a disease known as maize rough dwarf.

RBSDV is primarily a pathogen of East Asia, with China, Japan, South Korea, and surrounding countries bearing the greatest disease burden. The virus disappears for years before re-emerging under favourable vector and climatic conditions, making its epidemic pattern particularly difficult to forecast and manage. A close relative, Maize rough dwarf virus, causes analogous disease on maize across parts of Europe and the Mediterranean, and RBSDV's vector L. striatellus is itself distributed from Southeast Asia into Europe, underlining the relevance of this viral group to European plant health monitoring.

As no commercially resistant rice varieties are yet available, management relies on disrupting transmission by the vector. Seedbed covers, chemical seed treatments, and early-season insecticide applications to reduce planthopper populations are the primary tools in use across Asia. The development of insecticide resistance in L. striatellus populations complicates this approach. Longer-term, resistance breeding is underway, with quantitative trait loci governing tolerance identified in several studies, and RNA interference strategies targeting both the virus and key vector transmission proteins showing promise in experimental systems.

This week's pathologist works on exactly the kind of high-throughput sequencing and molecular characterisation that underpins modern plant virus surveillance, including of the rice virome, the broader context from which RBSDV can emerge.

This week, we meet Imtiyaz Ahmad Mir, a doctoral candidate in plant pathology at the Hungarian University of Agriculture and Life Sciences (MATE), completing his PhD within the Genomics Research Group at the Institute of Plant Protection.

Imtiyaz grew up in a farming family in Kashmir. Watching crops lost to disease, and seeing how little protection most smallholders had against it, convinced him that plant pathology was where he needed to be. During his undergraduate studies in agricultural sciences, field programmes including the Rural Agriculture Work Experience Programme brought him into direct contact with farmers who rely on minimal plant protection measures against a wide range of fungal, bacterial, viral, and nematode pathogens.

His Master's research at the University of Kashmir followed, focussed on damping-off disease in brinjal under the temperate conditions of Kashmir. The work spanned isolation and identification of the causal organism, in vitro evaluation of systemic and non-systemic fungicides alongside fungal biocontrol agents, host genotype screening, and integrated disease management. It gave him a thorough grounding in applied plant pathology, and it made clear what the next step needed to be: moving from field observation into molecular-level disease diagnosis.

That move brought him to Hungary. His PhD centres on the detection and molecular characterisation of the rice virome in Hungarian cultivars, combining RNA extraction from field samples, high-throughput RNA sequencing, and bioinformatic analysis, with results validated through RT-PCR, cloning, Sanger sequencing, and phylogenetic analysis. He is applying the same approach to other crops beyond rice.

Early in the project, sequencing revealed the presence of Oryza sativa endornavirus (OsEV) in local Hungarian rice cultivars, the first molecular evidence for this virus in the region. His longer-term aim is to bring these molecular tools to bear on plant protection more broadly, building the diagnostic capacity needed for more precise, targeted disease management.

You can connect with Imtiyaz on LinkedIn to keep up to date with his PhD research.

Have a job, scholarship, or event to advertise? List it in Robigalia. I’ll help promote your opportunity or event to a global network of over 10,000 plant pathologists for free.

See you next Monday!

P.S. Why Robigalia? The name originates from the Ancient Roman festival dedicated to crop protection. You can read all about the history here: