Planta

Delivery of biomolecules into plant vascular tissues remains a barrier to managing diseases caused by insect vector-borne pathogens and to modifying phenotypes of established perennial crops. Inspired by the vascularized growth of crown galls induced by Agrobacterium tumefaciens, we repurposed the bacterium’s plant growth regulator (PGR) genes to engineer autonomously dividing, transgene-expressing plant cell structures termed symbionts. A plant transformation vector (pSYM) incorporating the IaaM, IaaH, Ipt and gene5 cassette from A. tumefaciens strain C58 together with a gene of interest on the same transfer DNA was delivered to stems of herbaceous and woody dicots using disarmed A. tumefaciens strain EHA105. Symbiont morphology, vascular differentiation, transgene expression, molecular mobility and protein secretion were evaluated using microscopy, fluorescent reporters, dye tracing, RNA silencing assays and mass spectrometry-based proteomics. pSym inoculation reproducibly generated symbionts across diverse host plant species that were vascularly integrated into their host plants and transgene expression ranging from heterogeneous niches to more uniform patterns. Small molecules moved between symbionts and host vascular tissues, whereas larger proteins exhibited more restricted mobility. Post-transcriptional gene silencing signals moved freely throughout the symbiont and slightly into adjacent stem tissue. Under tested field and greenhouse conditions in potato and tomato, respectively, gall or symbiont formation had no negative impacts on plant growth or tuber and fruit yield. In vitro, symbiont cultures abundantly secreted recombinant protein into surrounding media. Together, these results establish symbionts as a modular, plant bioengineering platform capable of producing and potentially delivering biomolecules without modifying the host plant genome, providing a foundation for vascular-targeted therapeutics and phenotype modulation in crops.

Jasmonic and salicylic acids are key hormones involved in plant responses to pests and pathogens. Existing fluorescence-based approaches to imaging plant defence hormones are constrained by the need for external illumination and by autofluorescence of plant tissues, while luminescence-based ones require exogenous substrates. Here, we use jasmonate- and salicylate-responsive promoters to engineer autoluminescent plants that report hormone signalling activity with up to a 53-fold contrast. Using consumer-grade cameras, we image reporter Arabidopsis thaliana and Nicotiana benthamiana plants throughout normal development and in response to pest and pathogen attacks, visualising local and systemic responses. Because the luminescence is self-sustained, these reporters enable non-invasive, substrate-free imaging of defence signalling over extended time courses without specialised equipment.

Honey, a cherished natural product, is vulnerable to adulteration, posing challenges to food authenticity and safety. Barley malt syrup (BMS) has emerged as a new form of adulterant, complicating detection efforts. This study explores the significance of electronic nose (e-nose) and electronic tongue (e-tongue) technologies for detecting BMS adulteration in honey. Through comprehensive analysis, we assessed the efficacy of sensory evaluation based on human perception, physicochemical properties such as color, rheology, and sensor-based methods in discerning BMS adulteration levels ranging from 5% to 100%. Adulteration with BMS resulted in distinct shifts in sensor responses, with higher percentages of BMS leading to the dominance of BMS’s sensory characteristics over those of the honey. The compounds such as 1-octanol, hexanoic acid, and butanoic acid mainly contribute to fresh floral notes or the aroma profile of honey. Further, ethyl 3-(methylthio) propanoate and 2,4-heptadienal compounds are responsible for in-depth flavor for BMS. The concentration of ethyl 3-(methylthio) propanoate and 2,3-pentanedione have also been increased as the percentages of adulteration increases. The findings reveal that the e-nose and e-tongue demonstrate sensitivity and accuracy in detecting BMS adulteration at levels as low as 5%. Furthermore, the PCA plots provided valuable insights into sensor responses: the e-nose achieved 99.84% discrimination on PC1, while the e-tongue demonstrated 95.94% discrimination on PC1 and 3.27% discrimination on PC2, thereby enhancing the reliability of detection. These studies underscore the potential of e-nose and e-tongue as rapid, nondestructive tools for ensuring honey authenticity.

Der Fokus der vorliegenden Arbeit liegt auf der Entwicklung und Validierung eines Machine Learning (ML)-Modells, das die CO₂-Assimilation von Zea mays aus Chlorophyllfluoreszenzparametern vorhersagt. So soll die methodische Lücke zwischen den aufwendigen Gaswechselmessungen und der schnellen, nicht-invasiven PAM (Pulse-Amplitude- Modulated)-Fluorometrie geschlossen werden, um eine skalierbare, hochauflösende Analyse der Fotosynthese unter variablen Umweltbedingungen zu ermöglichen. Erstmals wurden umfangreiche, simultan erhobene Gaswechsel- und PAM-Daten unter kontrollierten Laborbedingungen aufgenommen, um darauf aufbauend ein ML-basiertes Vorhersagemodell zu entwickeln. Neben der Gesamt-Photonenflussdichte (bis zu 9500 PAR (Photosynthetically Active Radiation)) und dem Lichtspektrum wurden physiologische Faktoren wie Pflanzenalter, Blattposition, Blattsegment und Anzuchtbedingungen systematisch variiert. Die Beleuchtung wurde für monochromatischen Farben (Blau, Grün, Rot) und in definierten Misch- und Vollspektren durch Hochleistungs-LED (Light Emitting Diode)-Module umgesetzt. Damit wurden erstmals Bereiche von Photonenflussdichten bis 10 000 PAR zugänglich. Drei ML-Verfahren kamen zur Modellierung zum Einsatz: Support Vector Regression (SVR), K-Nearest Neighbors (KNN) und Random Forest. Die Datenbasis beinhaltet einen minimalen Datensatz, bestehend aus Y(II) (Effektive Quantenausbeute des Photosystems II), ETR (Elektronentransportrate), Photonenflussdichte und Pflanzenalter. Darüber hinaus wurde ein erweiterter Datensatz erstellt, in den zusätzlich die spektrale Zusammensetzung einfließt. Dabei werden nicht nur die relativen Anteile einzelner Wellenlängen berücksichtigt, sondern auch deren kombinierte Wechselwirkungen. Auf diese Weise lassen sich Effekte erfassen, die nicht allein durch die Intensität einer einzelnen Wellenlänge erklärt werden können, sondern erst durch das Zusammenwirken mehrerer Spektralanteile entstehen. Die Nutzung des Random Forest-Regressors war der leistungsstärkste Ansatz (R² = 0,93; MSE = 2,22) und lieferte robuste Vorhersagen. Die Analyse zur Feature Importance zeigt, dass neben der Gesamt-Photonenflussdichte insbesondere spektrale Komponenten, die ETR und Y(II) als entscheidende Faktoren für die Vorhersage gelten. Die physiologischen Daten, die parallel erhoben wurden, zeigen weitergehend, wie Zea mays unter extremen Lichtbedingungen reagiert. Die höchsten CO2-Assimilationsraten (bis zu 33,4 µmol/(m²s) bei 3400 PAR) wurden unter Grünlicht erreicht. Das widerspricht der klassischen Annahme einer geringen physiologischen Bedeutung des Grünlichts und ist möglicherweise auf tiefere Lichtpenetration und die Aktivierung photosynthetisch aktiver Zellen in den unteren Blattregionen zurückzuführen. Zea mays zeigte zudem eine hohe Toleranz für Rotlicht, jedoch traten bei hohen Rotlicht-Anteilen energetische Dysbalancen auf. Das Optimum der CO₂-Assimilation wurde bei einem Rotanteil von etwa 50 % im Mischspektrum erreicht. Phototropin-vermittelte Stomataöffnung und erhöhte Transpiration durch Blaulicht unterstützen die CO₂-Assimilation. Trotzdem wirkte Blaulicht hemmend auf Zea mays, was zu einer reduzierten PSII (Photosystem II)-Effizienz und einer erhöhten NPQ (Non-Photochemical Quenching)-Aktivität führte. Der Datensatz dieser Arbeit wird durch physiologische Einflussfaktoren erheblich erweitert und differenziert. In der sechsten Wachstumswoche, infolge fortschreitender pflanzlicher Seneszenz, sank die CO₂-Assimilationsrate von Zea mays um etwa 75 % im Vergleich zu jungen, voll photosynthetisch aktiven Pflanzen. Darüber hinaus wurden intrinsische Unterschiede zwischen verschiedenen Blattsegmenten und -stellungen beobachtet. Außerdem wurde die maximale CO₂-Assimilationskapazität durch eine hohe Anzucht-Photonenflussdichte signifikant verbessert. Pflanzen, die unter Hochlicht-Anzuchtbedingungen kultiviert wurden, zeigten unter optimalen sowie unter extremen Hochlichtbedingungen höhere CO₂-Assimilationsraten. Damit leistet diese Arbeit zwei wichtige Beiträge. Zum einen ein erklärbares, validiertes ML-Modell, das PAM-basierte Fluoreszenzdaten zuverlässig in CO₂-Assimilationsraten umwandelt und somit in vielen Hochdurchsatz-Anwendungen die Gaswechselmessungen ersetzen kann. Zum anderen neue physiologische Erkenntnisse zur spektralen Optimierung der Fotosynthese bei Hochlicht, vor allem zur bislang wenig beachteten Bedeutung des Grünlichts. Diese Methoden bilden zusammen die Grundlage für schnellere und präzisere Fotosynthesemessungen, die unter realistischen und variierenden Umweltbedingungen skalierbar sind.

Zucchini yellow mosaic virus (ZYMV), a member of the family Potyviridae, was first reported in Italy in 1973 (Desbiez & Lecoq, 1997). Since then, it has been reported in various regions worldwide, including Asia, Europe, Africa, and the Americas. This virus has caused severe economic epidemics in cucurbit crops globally, causing symptoms such as mosaic, foliar mottling, and fruit deformities (Berbati et al., 2023; Ali; Damayanti et al., 2021; Clarke, 2020). In Peru, this virus is causing severe damage to cucurbit crops. This study reports the detection of ZYMV in a Macre squash (Cucurbita maxima) fields through high-throughput sequencing (HTS) and Sanger sequencing. In September 2022, C. maxima cv. Macre plants exhibiting symptoms of foliar mosaic and fruit deformation were observed in fields located in La Molina, Lima, Peru. To assess the virus distribution in Peru, a total of 270 C. maxima samples comprising both symptomatic and asymptomatic plants were randomly collected between June and August 2023 from various regions: Chiclayo (25 samples), Lima (152), Ica (47), and Arequipa (46). ZYMV detection was performed using DAS-ELISA (DSMZ, QC-SOP-0087), revealing a prevalence of 60–71%. From these, a symptomatic young leaf was collected from each of the five plants (M1, M2, M3, M4, and M5) to extract total RNA using the SV Total RNA Isolation System kit (Promega) and lyophilize them. RNA from the M1 sample was used to construct a ribosomal RNA-depleted library and sequenced on the NextSeq 1000 platform, yielding 30 million 150 bp paired-end reads. Data were processed via the Galaxy platform following Mendoza et al. (2022). Trimmomatic v0.32 was used to trim low-quality reads, resulting in 59,262,180 reads, which were assembled into 77,583 contigs with SPAdes v3.12.0. Contigs were analyzed by tBLASTx against the RefSeq2022 viral database using Geneious vR11 (Biomatters, NZ) A total of 140 contigs exclusively corresponding to ZYMV were identified and assembled de novo, generating a consensus sequence of 9,484 nt with 98.9% identity to a ZYMV sequence from the United Kingdom by (Cucurbita pepo; GenBank OM471983) and 91.6 % identity to one from Brazil (Citrullus lanatus; GenBank MN364667). Mapping of the trimmed reads revealed 4,017,426 aligned reads with 65,544x coverage, confirming ZYMV as the sole causal agent of the observed disease. To validate the HTS-derived sequence, specific primers ZYMV4274_F/ZYMV4663_R and ZYMV8362_F/ZYMV9402_R were designed to amplify 412 bp and 1,063 bp fragments corresponding to the CI (GenBank PV599321) and the NIb C-terminal regions extending to the initial 3’UTR (GenBank PV599322), respectively, via RT-PCR. The amplified sequences from the M1 sample were confirmed through Sanger sequencing, showing 99.9% identity to the HTS-derived sequence. Additionally, ZYMV was reactivated from the lyophilized M1 sample by inoculating C. pepo var. grey zucchini, which was subsequently used as the inoculum source for mechanical inoculation on 21 plant species from the families Cucurbitaceae, Solanaceae, Lamiaceae, Fabaceae and Amaranthaceae. Symptomatic infection was observed seven days after inoculation in cucurbit species, including C. moschata, C. maxima, C. pepo, C. ficifolia, Cucumis sativus, C. melo and Citrullus lanatus, while Luffa spp. and Cyclanthera pedata showed no signs of infection. Meanwhile, Chenopodium quinoa and Ch. amaranticolor exhibited local chlorotic lesions on the inoculated leaves. All inoculated plants were confirmed by DAS-ELISA. Observed symptoms varied depending on species and cultivar, ranging from mild to severe mosaic, vein banding, leaf deformation, and vein clearing. To date, in South America, ZYMV has only been reported in Argentina, Brazil, Chile, Colombia, Guyana, Paraguay, and Venezuela (Spadotti et al., 2015). Therefore, this study represents the first official report of ZYMV in Peru with the isolate designated as ZYMV_Lim (GenBank OQ181225). The virus is widespread across major key squash-producing regions along the Peruvian coast.

The aim of this study is to structure the aspects of control and safety in technical systems using the concepts of entro-py, negentropy, and information, in order to identify additional factors for assessing controllability and loss of control in the process of decision-making or the loss of emergence. The article examines specific properties of ergatic systems that contribute to forming the informational basis for describing the structure, control, and safety levels of technical systems. A two-level ontological framework is proposed for evaluating the controllability of a technical system through the analysis of its informational characteristics. Negentropy is interpreted as an indicator of the system’s condition, reflecting the combined effect of internal properties and external influences on its functionality. The configuration and number of safety subsystems define the upper limits of controllability and safety within a technical system, including in scenarios involving emergence. The dualism of safety lies in capturing both the negentropy (describing the state of or-der in the system, as well as its actual — or worst-case — levels and structure of control and safety) and the infor-mation about the state of control and safety (expressed through the required number and configuration of safety sub-systems needed to achieve optimal performance). The article compares several concepts and regularities from infor-mation theory and thermodynamics for their applicability within the ontological framework of safety dualism. The analysis of safety dualism enables the comparison of structural and control architectures in technical system designs, the identification of factors contributing to successful or failed control, the definition of conditions under which emer-gence is lost, expert assessment of communication and control systems, and the development of optimal control and safety regimes—taking into account both resource depletion and the need for resource replenishment.

Background and AimsPhosphorus (P) is a crucial macronutrient for plant growth that, despite its abundance in soils, is often a limiting factor in agricultural productivity, particularly for cereals such as wheat. In this study, the response of different wheat genotypes to two different levels of P was evaluated in a large trial encompassing 26 genotypes using two distinct root phenotyping platforms, ALSIA and 4PMI.MethodsRhizotubes allowed non-invasive root phenotyping, revealing significant genotypic effects on biomass production and root system traits. Phosphorus acquisition and use efficiency of the wheat genotypes were estimated by using five different metrics.Key ResultsA synthetic indicator for agronomic relevance integrating the efficiency metrics was established. Under optimal conditions, after 96 d, P acquisition efficiency (PAE) was inversely correlated with P utilization efficiency (PUE), suggesting an acquisition–use trade-off. Conversely, under low P conditions, both after 27 and 96 days PAE and PUE showed moderate positive correlations, indicating adaptive coordination to improve P utilization under scarcity.ConclusionsOverall, our findings highlighted the importance of root–target strategies in P efficiency in wheat, providing insights for breeders to enhance P deficiency tolerance in wheat.

Corn stunt is one of the most significant corn diseases in the Neotropics, leading to severe plant stunting and substantial yield losses. Although four pathogens have been found either singly or in combination in infected plants in the Americas, the corn stunt spiroplasma (Spiroplasma kunkelii) have been the most predominant pathogen associated with the disease in the U.S., due to its widespread distribution in the Rio Grande Valley region and persistent occurrence in California and Florida. During the 2024 growing season, reports of chlorosis, leaf reddening, and stunting in corn fields in Southern, Great Plains, Central Corn Belt, and Northeastern states raised concern regarding the possibility of a more widespread distribution of corn stunt spiroplasma in the U.S. Symptomatic corn leaf samples were collected in commercial and experimental field sites across the U.S. Detection and identification of S. kunkelii were performed using a polymerase chain reaction assay targeting a section of the spiralin gene, followed by amplicon sequencing. This study provides the first report of the pathogen S. kunkelii associated with corn stunt symptoms distributed across six counties in Oklahoma, 14 counties in Kansas, two counties in Missouri and Arkansas, four counties in New York, and one county in each of Nebraska, South Dakota, Wisconsin, Minnesota, Indiana, and Alabama. All states with submitted samples had at least one confirmed case of S. kunkelii.

Cucurbit yellow vine disease (CYVD), which is caused by the gram-negative bacterium Serratia marcescens and transmitted by squash bugs (Anasa tristis DeGeer), is a devastating disease of cucurbit crops that is emerging rapidly in the eastern half of the United States. The lack of a robust pathogenicity assay for CYVD in the laboratory has hampered functional tests using genomic sequences to investigate the biology of this phytopathogen. In this study we developed and validated a bioassay that yielded consistent and quantifiable CYVD symptoms on squash in the laboratory. We compared inoculation by wounding with a multipronged floral pin frog to inoculation by injection in which a needle was moved in and out of the stem multiple times in each of multiple piercings to mimic the feeding behavior of squash bugs. We found that inoculation by needle injection of ≥108 CFU/ml of S. marcescens into the stem of squash (Cucurbita pepo) plants at the cotyledon growth stage reproducibly induced CYVD symptoms, whereas injecting 106 or 107 CFU/ml did not. Additionally, we found that S. marcescens induced symptoms on all of the squash cultivars tested, and induced symptoms that have not been previously reported, including stem elongation and leaf cupping. In short, through our injection approach of mimicking the natural process of S. marcescens transmission by squash bug feeding, we obtained robust and quantifiable CYVD symptoms. This laboratory bioassay provides a crucial tool for investigating the biology and pathology of this emerging pathogen and for plant breeding screens aimed at combatting CYVD.