Fig. 3. PsyI and PsyR contribute to suppression of salicylic acid marker gene expression. The relative expression of PATHOGENESIS RELATED 2b (PR2b) in tomato leaves at 1 and 3 days after vacuum infiltration with 1 mM MgCl2 (mock treatment) or bacterial inoculum (1 × 105 CFU ml−1). Relative gene expression was calculated based on the expression of the reference gene PP2ACS. Results are shown as the mean (n = 6) ± standard error. Different letters on top of bars indicate significant statistical differences among the means (analysis of variance and Scott–Knott's test α = 0.05).

Findings from Jirachaya Yeemin et al. suggest the psyI and psyR genes of #Pseudomonas syringae pv. tomato DC3000 contribute to bacterial virulence on tomato: https://doi.org/10.1094/PHYTO-05-25-0192-R

Fig. 3. Gene content comparison and synteny between the copper resistant plasmids of closely related xanthomonads. XAP, Xanthomonas arboricola pv. pruni (CP189571); XE, X. euvesicatoria (CP137533); XCC, X. citri subsp. citri (CP023286); XP, X. perforans (CP108472); XHG, X. hortorum pv. gardeneri (CP018732); XV, X. vesicatoria (CP018468). The figure was created with Easyfig. The right side displays the percentage of similarity (top) and percentage of coverage (bottom) for each sequence. Plasmid genomes are presented by linear visualization, with coding regions shown as arrows. The percentage of sequence similarity is indicated by the intensity of blue (for normal mapping) and green (for inverted mapping) color.

#Xanthomonas arboricola pv. pruni (XAP) causes bacterial spot in Prunus, and copper sprays have been widely used to manage this disease. Milan Panth et al. report and characterize the first copper-resistant strain of XAP, first isolated in North Carolina: https://doi.org/10.1094/PHYTO-10-25-0338-R

Call for Papers! Seedborne Pathogens: Risks, Research, and Resilience

Call for Papers: Submit to the forthcoming Phytopathology focus issue, “Seedborne Pathogens: Risks, Research, and Resilience,” by June 15, 2026!

Learn more:
https://apsjournals.apsnet.org/seedbornepathogens

Fig. 2. The silencing suppressor capability of potato leafroll virus (PLRV) P0 wild type (wt), PLRV P0 mutants, and a panel of viral suppressors of RNA silencing (VSRs) transiently expressed in Nicotiana benthamiana leaves. The abaxial side of N. benthamiana leaves was co-inoculated with Agrobacterium tumefaciens vectors expressing the PLRV P0 wt construct, PLRV-P0 mutants, turnip crinkle virus (TCV) P38, cotton leafroll dwarf virus (CLRDV) P0, tomato bushy stunt virus (TBSV) P19, and cucumber mosaic virus (CMV) 2b, together with Agrobacterium vectors expressing green fluorescent protein (GFP) and double-stranded (ds)GFP, in a 1:1:1 ratio to evaluate the suppressor activity. For controls, N. benthamiana leaves were infiltrated with an Agrobacterium vector containing only GFP and with GFP and dsGFP in a 1:1 ratio. Photographs were taken at 3 days post-infiltration under a long-wavelength UV lamp.

“Viral Silencing Suppressor Activity in Plants Modifies Aphid Antiviral Immunity and Fecundity,” by Stephanie E. Preising et al. Learn more: https://doi.org/10.1094/PHYTO-05-25-0173-R #aphids

Fig. 5. Comparison of log2-transformed fold changes (Atnhr2b Atnhr2a versus Col-0) of differentially abundant proteins (DAPs) with signal peptides identified in both the apoplast and the whole leaf proteomes at 24 and 72 h after inoculation (hai). The color scale represents the relative abundance of each DAP: green highlights DAPs with lower abundance, red indicates DAPs with higher abundance, and gray represents no change in abundance.

Findings from Thiago Maia et al. support a model in which AtNHR2A and AtNHR2B function as integral components of the plant endomembrane system, modulating the secretion and accumulation of specific apoplastic proteins during immune responses: https://doi.org/10.1094/PHYTO-07-25-0237-R

Fig. 6. Spore flight direction and magnitude of Cercospora beticola DNA concentrations associated with spore dispersal in 2021 at two locations (location “a” [left] and location “b” [right]). Arrow colors indicate different sampling days.

Facundo Ramón Ispizua Yamati et al. present the first study to integrate mechanistic disease models, meteorological data, uncrewed aerial vehicle imagery, and molecular diagnostics into a single predictive framework for the Cercospora beticola pathosystem: https://doi.org/10.1094/PHYTO-03-25-0113-R

Fig. 2. Normal appressoria (arrows) formed on all gravity treatments on both Cucurbita pepo and Arabidopsis thaliana tissues. A, Most appressoria appeared to form on the ends of the primary germ tubes within 40 to 50 µm from conidia after 2 or 3 days postinoculation (dpi). B, However, many appressoria were observed on distal ends and inline of much longer germ tubes in excess of 100 µm at 3 dpi. Both photos are of appressoria on C. pepo leaf discs; similar structures were observed on 3 dpi A. thaliana leaves.

Editor’s Pick: Results from Andrew C. Schuerger et al. suggest that simulated microgravity increases phytopathogen growth rates, potentially leading to increased levels of disease in space-based bioregenerative life support systems: https://doi.org/10.1094/PHYTO-11-25-0359-R

Fig. 1. Angular leaf spot (ALS) on common bean. A, ALS symptoms on common bean differential line G11796. B, Conidia of Pseudocercospora griseola. C, Fasciculate conidiophores. Scale bars: B = 25 µm and C = 150 µm.

Unexpected Potential Bacterial Symbiosis Found in Fungus That Causes Angular Leaf Spot: www.apsnet.org/members/community/newsro...

Read the original article by Luz M. Serrato-Diaz et al. to learn more: https://doi.org/10.1094/PHYTO-09-24-0302-R

Fig. 1. Pierce's disease (PD) leaf scorch symptoms and leaf loss scores (leaf scorch-leaf loss [LS-LL]) means over 15 weeks in trial 1. The dashed lines indicate the LS-LL scores at which the grapevine accessions were considered resistant (<1.5), tolerant (1.5 to 3.5), or susceptible (>3.5). The data points represent the means ± SE (n = 5 plants per accession per inoculation treatment). Lowercase letters were used for the differences among the grapevine accession and uppercase letters for the differences between both Xylella fastidiosa (Xf) strains. N.S., no significance.

Karla Gabriela Huerta-Acosta et al. shed light on the differential responses of grapevine accessions to the #Xylella fastidiosa strains prtA− and Tem1: https://doi.org/10.1094/PHYTO-06-25-0200-R

Fig. 1. Dendrogram based on average nucleotide identity (ANI) values, showing the genomic similarity among strains from the different Xanthomonas species, including the two sweet cherry isolates T2.1 and T2.2. This is not a phylogenetic tree but a similarity-based clustering derived from pairwise ANI comparisons.

“Revisiting the Identification of Xanthomonas arboricola Strains Isolated from Cherry in Montenegro Through Genome Analysis and Pathogenicity Testing,” by Sara Cuesta-Morrondo et al. Learn more: https://doi.org/10.1094/PHYTO-05-25-0168-SC

K. Avila et al. found that fly density does not limit #Ceratocystis fimbriata transmission to sweetpotato by #Drosophila hydei: https://doi.org/10.1094/PHYTO-04-25-0122-R 🍠

Fig. 6. Transcriptional activity assay of TaMYB73. A, Phenotype of yeast two-hybrid (Y2H) Gold yeast strain with BD-TaMYB73 on an SD/-Trp/X-α-gal/AbA medium. Yeast solutions were spotted on SD/-Trp, SD/-Trp-Leu/X-α-gal and SD/-Trp/X-α-gal/AbA media. B, Phenotype of Y2H Gold yeast strain with BD-TaMYB73 on an SD/-Trp medium with different concentrations of 3-AT. The 3-AT concentrations were 0, 10, 20, 30, 40, 50, 60, and 70 mM.

Findings from Yuyang Liu et al. establish TaMYB73 as a positive regulator of high-temperature seedling plant resistance in wheat. Learn more: https://doi.org/10.1094/PHYTO-11-23-0427-R

Fig. 2. Multilocus genotypes (MLGs) of Phytophthora × alni detected between 2005 and 2010. Locations of the original collection (with both original and recent isolates of P. × alni acquired) are highlighted. A, MLGs detected between 2005 and 2010. B, MLGs detected between 2020 and 2024.

“Population Structure of Phytophthora × alni on a Local Scale and Its Temporal Development,” by Štěpán Pecka et al. Learn more: https://doi.org/10.1094/PHYTO-03-25-0091-R

Fig. 3. The morphological effects on Botrytis cinerea strain CGMCC3.20932 hyphae exposed to varying doses of eugenol in potato dextrose broth for 24 h were observed using transmission electron microscopy. A, Control (CK) (0.0 µg/ml eugenol). B and C, Eugenol treatment at the 30% effective concentration (EC30) dose (46.13 µg/ml). D and E, Eugenol treatment at the EC50 dose (72.11 µg/ml). F, Eugenol treatment at the EC90 dose (214.86 µg/ml). CW, cell wall; Cy, cytoplasm; M, mitochondria; N, nucleus; PM, plasma membrane. Bars = 1 μm. The experiment was independently conducted three times, and similar results were obtained.

Eugenol exhibits a spectrum of antimicrobial activities and fungicide efficacy against crop diseases. Xiansu Wang et al. assessed its inhibitory activity against many phytopathogenic fungi, finding it to be particularly effective against #Botrytis cinerea: https://doi.org/10.1094/PHYTO-06-25-0227-R

Findings from Tania Afroz et al. reveal a major vulnerability in current commercial cotton cultivars and emphasize the urgent need to screen diverse genetic material for novel resistance to #Meloidogyne enterolobii. Learn more: https://doi.org/10.1094/PHYTO-07-25-0240-R

“Unmasking Tomato Spotted Wilt Virus in Peanuts: From Nucleocapsid Protein Sequence and Localization to Practical Management in Alabama,” by Abdelaal H. A. Shehata et al. Learn more: https://doi.org/10.1094/PHYTO-06-25-0204-R

Fig. 6. Phenotype observation of plant between wild-type and transgenic Brassica napus lines. Phenotypic observations of whole plants, flowers, and fruit capsules of the A, wild-type; B, A1; and C, A2 strains. The line segment in the lower right corner represents 2 cm.

Fupeng Hou et al. cloned PfPDF2 from Perilla frutescens and introduced into Brassica napus through Agrobacterium-mediated transformation. Results showed the transgenic plants were significantly more resistant to Botrytis cinerea and Alternaria brassicae: https://doi.org/10.1094/PHYTO-09-25-0293-R

Results from Bhavya Shukla et al. indicated the difference in virulence between tomato spotted wilt virus isolates from peanut, tobacco, and tomato crops on #Nicotiana tabacum: https://doi.org/10.1094/PHYTO-04-25-0142-R

Fig. 2. The subcellular localization of ethylene receptor 2 (CsETR2) in Nicotiana benthamiana leaves. 35S::EGFP was transiently expressed in N. benthamiana leaves as a positive control. pCAMBIA1300-35S-ER-mCherry-HDEL was used as the endoplasmic reticulum (ER) marker. Scale bars = 20 μm.

Diseases of tea plants caused by #Lasiodiplodia theobromae have significantly impacted the quality and yield of tea leaves in China and India. Tianxinyi Pan et al. uncovered a novel disease resistance mechanism: https://doi.org/10.1094/PHYTO-03-25-0117-R

Fig. 3. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of Botrytis cinerea strain CGMCC3.20932 hyphae treated with osthole for 36 h.

Qi Luo et al. demonstrate that osthole disrupts energy metabolism, nitrogen metabolism, substance transport, and metabolism of the hyphal cell wall and cell membrane, potentially targeting the amidase of #Botrytis cinerea: https://doi.org/10.1094/PHYTO-06-25-0203-R

Fig. 1. A, Map of Georgia, United States, showing the sampling locations. B, Representative tomato spotted wilt virus (TSWV)-infected leaf symptoms from four genotypes: two cultivars (GA-06G, Bailey II) and two allotetraploids (GregSten, VallsiiWilliamsii). Scale = 1 cm. C, Schematic diagram of the TSWV genome, showing segments L (blue), M (purple), and S (green) with their open reading frames (ORFs). ORFs are shown as rectangular blocks with arrowheads indicating strand orientation (sense or antisense). The ends of each segment represent the 5′ and 3′ untranslated regions (UTRs), and the line between two ORFs denotes the intergenic region. Numbers below each segment indicate the size range observed in the four isolates from this study, with the percentage values below the ORFs representing their relative size compared with the entire segment.

Tomato spotted wilt virus (TSWV) is a globally important pathogen of peanut. Namrata Maharjan et al. performed deep sequencing of TSWV isolates from two peanut cultivars and two induced allotetraploids derived from four wild Arachis grown in Georgia: https://doi.org/10.1094/PHYTO-08-25-0271-R

“What a walk down memory lane! Thank you for bringing these landmark papers together into a wonderful resource for teaching!” —Jan E. Leach (Colorado State University)

Explore the virtual issue: https://apsjournals.apsnet.org/landmarksphyto

Fig. 1. Minimum spanning network for 399 Stemphylium vesicarium multilocus genotypes (MLGs) based on Bruvo's measure of genetic distance for isolates obtained from transplants, volunteers, and main crop onion plants in New York across 2022 and 2023. Each node represents an MLG, and the node size represents the number of isolates corresponding to each MLG.

“Relative Contributions of Infected Transplants and Volunteers to the Population Biology of Stemphylium vesicarium in New York Onion Production,” by Natalia Piñeros-Guerrero et al. Learn more: https://doi.org/10.1094/PHYTO-06-25-0209-R

Call for Papers! Exploring Pantoea: Dual Roles in Plant Health and Disease. A Phytopathology Pathogen Spotlight

Deadline approaching: Submit to “Exploring Pantoea: Dual Roles in Plant Health and Disease,” by March 31, 2026! Learn more: https://apsjournals.apsnet.org/pantoeapathogenspotlight

Fig. 1. Geographical location of experimental sites used to examine the performance and stability of commercial winter wheat cultivars to Stagonospora nodorum blotch epidemics in North Carolina. Gray contours and colors represent counties and level III ecoregions (U.S. Environmental Protection Agency), respectively. The dots on the map indicate locations, abbreviated names and year, and their shapes represent ecoregions in which trials were conducted.

Vinicius C. Garnica, Mohammad Nasir Shalizi, and Peter S. Ojiambo investigated the effects of genotype-by-environment interactions on 4 disease metrics describing #Stagonospora nodorum blotch epidemics of 18 commercial soft red winter wheat cultivars: https://doi.org/10.1094/PHYTO-12-24-0398-R

Fig. 1. Determination of the conidiation capacity of Fusarium pseudograminearum. The conidiation capacity of two populations on a 6% mung bean broth medium in a rotary shaker at 175 rpm (25°C, 4 days). The same lowercase letters indicate no statistical significance (P < 0.05). 3AcDON, 3-acetyl-deoxynivalenol; 15AcDON, 15-acetyl-deoxynivalenol.

Editor’s Pick: Findings from Xiangxiang Zhang et al. highlight the role of temperature and drought in shaping the geographic distribution of #Fusarium pseudograminearum populations and provide insights into the environmental adaptability of the fungus: https://doi.org/10.1094/PHYTO-08-25-0288-R

Fig. 10. Detection results. A, Brown spot. B, Rice blast. C, Bacterial blight. D, Brown spot and rice blast.

“A Multi-Scale Perception-Enhanced Lightweight Network with Knowledge Distillation for Rice Leaf Disease Detection,” by Manyi Wang et al. Learn more: https://doi.org/10.1094/PHYTO-05-25-0161-R

Fig. 7. A, Symptoms observed on Pelargonium × hortorum ‘Maverick White’ agroinfected with the pPVBV_IC construct; plants displayed mosaic and chlorosis around the veins, along with distortion and deformation on new growth. B, Bacilliform-shaped virus particles observed in the partially purified extract by transmission electron microscopy. Virions were partially purified from symptomatic leaves of agroinfected P. × hortorum ‘Maverick White’. C, Comparison of a mock-inoculated Maverick White plant (left) and a plant agroinfected with the pPVBV_IC construct (right).

#Caulimoviridae is comprised of plant-infecting pararetroviruses that replicate by reverse transcription and encapsidate a circular double-stranded DNA genome. Sita Paudel et al. report and characterize a new badnavirus infecting Pelargonium × hortorum: https://doi.org/10.1094/PHYTO-12-24-0389-R

Fig. 1. In vitro RNA2 transcription by nuclear inclusion protein b (NIb) of the wheat yellow mosaic virus (WYMV). A, Structural diagram of recombinant plasmid pMAL-WY-NIb. B, In vitro RNA2 transcription by WYMV NIb. 5U is 160 nt, int is 160 nt, and 3′ is 190 nt. MBP, maltose-binding protein. Numbers under the RNA gel map indicate the amount of the complementary strand synthesized by maltose-binding protein (MBP)-NIb, and numbers in parentheses indicate the STEV (standard deviation estimation value), a function that estimates the standard deviation based on the variance of the sample mean.

Findings from Guowei Geng et al. provide an empirical basis for in vivo experiments on regulation of wheat yellow mosaic virus (WYMV) genome replication and provide a theoretical basis for the prevention and control of WYMV-related crop diseases: https://doi.org/10.1094/PHYTO-05-25-0158-SC

Fig. 1. Discovery and validation of Xanthomonas citri pv. bilvae from an 1848 herbarium specimen. A, Photograph of the original herbarium sample with sampled symptoms highlighted with the red frame.

Claudine Boyer et al. present novel genomic data for #Xanthomonas citri pv. bilvae, the causal agent of bacterial shot-hole disease in bael trees. Learn more: https://doi.org/10.1094/PHYTO-07-25-0255-SC