PlantChatter

Plants lack specialized immune cells and instead rely on coordinated cellular responses to restrict pathogen invasion while preserving tissue integrity. How plant immunity spatially organizes these responses remains unclear. Using live-cell reporters in Arabidopsis infected with Pseudomonas syringae, we show that effector-triggered immunity, superimposed on pattern-triggered immunity, establishes a sustained yet spatially confined immune architecture at the infection front. Defense activation persists for days but remains restricted to a narrow ring of cells surrounding viable bacterial microcolonies. Over time, immune activity spreads to adjacent layers, forming a coordinated, multilayered defense zone. This zonation extends beyond transcriptional activation to polarized callose deposition at pathogen-facing cell walls, reinforcing a localized containment boundary that limits pathogen spread. Consistent with previous single-reporter studies, simultaneous visualization of salicylic acid (SA) and jasmonic acid (JA) biosynthesis and response markers reveals a radial hormone gradient, with SA-enriched cells proximal to bacterial colonies and JA-enriched cells in surrounding regions. Individual cells predominantly activate one pathway, indicating that SA-JA antagonism is resolved through spatial compartmentalization across neighboring cells. Together, these findings establish immune zonation as a strategy for robust pathogen containment while minimizing collateral tissue damage. ### Competing Interest Statement The authors have declared no competing interest. National Institutes of Health, R35GM136402 University of Missouri, https://ror.org/02ymw8z06

Long-read sequencing has shown a rapid technological development during the last years. It has been established as the standard method for the sequencing of plant genomes and has also gained importance for full plasmid sequencing. As Sanger sequencing has a limited read length of about 1 kb, long read sequencing offers a great advantage, as the full plasmid can be sequenced in one read. Here, we present a cost-effective workflow to sequence full plasmids and compare the results against an expectation. The per plasmid cost of this workflow is determined by the number of plasmids investigated simultaneously, but can be lower than the price of a single Sanger sequencing reaction. We developed a workflow for automatic data processing, which allows us to complete sequencing and data analysis within a day. ### Competing Interest Statement The authors have declared no competing interest.

Root-knot nematodes are obligate plant parasites that cause substantial agricultural losses worldwide. They induce highly specialized, metabolically hyperactive feeding sites within host roots, which serve as their sole source of nutrients throughout their life cycle. The formation and maintenance of these feeding sites depend on the manipulation of host developmental pathways by nematode-derived secretions. Phytosulfokines (PSKs) are small plant peptide hormones that regulate cell division, tissue expansion, and growth responses, processes essential for feeding site development. Here, we identify root-knot nematode genes predicted to encode peptides with a conserved PSK functional motif. These genes are predominantly expressed during the early stages of infection and localize to secretory glands, suggesting a role in early parasitism. Moreover, silencing PSK-like gene expression reduces root gall formation and nematode reproduction. Together, these findings reveal that root-knot nematodes deploy PSK-like peptides as virulence factors to promote successful parasitism, providing the first report of PSK peptide mimicry in any plant pathogen. ### Competing Interest Statement The authors have declared no competing interest.

This working paper presents a co-creation approach to developing and scaling data-driven solutions based on the WaPOR database. The co-creation approach customizes tools derived from the WaPOR portal to local needs, making them more relevant, user friendly, and adapted to various contexts, stimulating ownership and supporting wider adoption. The process involves engaging stakeholders, identifying challenges, co-designing solutions, and incentivizing adoption, with stakeholders continuously engaged to prioritize and address emerging needs.

Background and aims Rapid warming has driven widespread upslope plant migration, often involving woody expansion in alpine ecosystems. In contrast, on Changbai Mountain, the low-elevation graminoid Deyeuxia angustifolia is encroaching into tundra dominated by the native shrub Rhododendron aureum. This atypical herb-into-shrub expansion threatens shrub persistence and may undermine biodiversity and carbon storage, underscoring the need to understand how herbaceous encroachment shapes native shrub trait responses. Methods Along an encroachment gradient of D. angustifolia into a R. aureum-dominated tundra on Changbai Mountain, we measured 47 functional traits of R. aureum to explore changes in trait means, intraspecific variation (ITV), trait integration, and their links to soil properties. Results Compared with non-encroached plots, R. aureum exhibited lower biomass (− 20.76%) and seed mass (− 46.89%) in plots with D. angustifolia encroachment. Moreover, R. aureum also showed thinner, larger, and more nutrient-enriched leaves, lower root carbon and non-structural carbohydrate concentrations, and more acquisitive trait syndromes. Intraspecific variation in energy-storage and water-use traits was higher, whereas variation in nutrient-use traits was lower. Trait integration was higher, with 60%–100% greater network edge density, especially among leaf–shoot traits. Hub traits shifted from root traits in non-encroached plots to leaf traits in encroached plots. Conclusions Overall, encroachment was associated with a shift in trait strategies from high means to enhanced cross-organ integration, accompanied by changes in shading, snow–soil thermal conditions, and nutrient availability. This reorganization represents a carbon-limited compensatory strategy that improves resource acquisition but cannot prevent declining performance, providing mechanistic insight into shrub persistence and tundra vegetation trajectories under climate warming.

The FAO Strategy for Private Sector Engagement 2026–2030 builds on more than a decade of progress, stemming from the FAO Strategy for Partnerships with the Private Sector (2013) and the FAO Strategy for Private Sector Engagement 2021–2025. This new iteration marks a renewed, action-oriented and forward-looking approach to strengthening partnerships with the private sector in support of the FAO four betters.

This report examines the Lake Tanganyika sprat and sardine value chain in Zambia, applying the FISH4ACP methodology to identify opportunities for sustainable growth and inclusive development. Conducted between 2022 and 2023, the analysis includes four main components: functional analysis, sustainability assessment, upgrading strategy development, and implementation planning. The proposed upgrading strategy targets three key outcomes: broader adoption of improved practices and market access by value chain actors; enhanced economic, social, and health conditions for women, youth, and children; and enhanced sustainable fisheries management across Zambia’s kapenta sector.

Gene drives offer revolutionary potential for the management of problematic plant populations, such as invasive weeds and herbicide-resistant species, by rapidly spreading desired genetic alterations. Two recent studies have provided experimental demonstrations of engineered CRISPR gene drive systems in plants (CAIN and ClvR). However, the successful application of such systems in the field will critically depend on an accurate understanding of plant-specific life-history traits, especially seed dormancy, a ubiquitous yet frequently overlooked eco-evolutionary force. In this study, we develop a comprehensive modelling framework for gene drives in plant populations that incorporates a persistent soil seed bank. We show how the presence of a seed bank can substantially slow gene drive spread but also reduce the genetic load required to achieve population elimination. Furthermore, we show that seed banks substantially increase the required introduction frequency of threshold-dependent gene drives, which could prevent establishment in some cases, yet also provide an intrinsic biosafety mechanism for confining a highly efficient drive to a target population. Our study highlights the need to incorporate seed-bank dynamics into gene drive strategies to ensure realistic predictions and successful field applications. The authors present a comprehensive plant-specific modelling framework for CRISPR gene drives: dormant seed banks can slow spread and require larger releases but can also ease weed elimination and limit unintended spread to nearby populations.

Molecular Plant-Microbe Interactions

Strigolactones (SLs) are plant hormones regulating shoot branching and symbiotic interactions, but their trace-level abundance limits research and applications. Here, we optimized a Nicotiana benthamiana transient expression system for SL production by tuning agroinfiltration parameters and co-expressing rate-limiting carotenoid biosynthetic genes. Overexpression of Zea mays PSY1 or an Arabidopsis PSY-GGPS11 fusion increased carlactone production over 2-fold and enhanced downstream SL accumulation. Using this platform, we discovered that sorghum cytochrome P450 SbCYP728B35 catalyzes conversion of 5-deoxystrigol to sorgolactone, revealing a previously unknown function. These results establish metabolic engineering of precursor supply as an effective strategy for boosting SL production and demonstrate N. benthamiana as a robust system for pathway elucidation and biotechnological synthesis of bioactive strigolactones. ### Competing Interest Statement The authors have declared no competing interest. Yuelushan Laboratory Breeding Program, YLS-2025-ZY04002, YLS-2025-ZY03001, YLS-2025-ZY01004 National Natural Science Foundation of China, 32400258 Outstanding Youth Project of the Natural Science Foundation of Hunan Province, 2024JJ2013 National Key Research and Development Program of China, 2023YFD1401100 Hunan Science and Technology Innovation Plan, 2025ZYJ003 European Research Council (ERC) Advanced grant CHEMCOMRHIZO, 670211 Dutch Research Council (NWO/OCW) Gravitation programme Harnessing the second genome of plants (MiCRop), 024.004.014 Foreign Expert Project “High‐level Foreign Expert Introduction Plan” by Ministry of Science and Technology of China, Z202304492179 Hunan Provincial Innovation Foundation For Postgraduate, CX20240386

The YokF endonuclease provides a donor-controlled mechanism to limit plasmid transfer to recipient bacteria via nanotubes in Bacillus subtilis, with YokF functional homologues found across Gram-positive bacterial species.