Auxin response factors (ARFs) play central roles in conferring auxin-mediated responses through selection of target genes in plants. Despite their physiological importance, systematic analysis of ARF genes in potato have not been investigated yet. Our genome-wide analysis identified 20 StARF (Solanum tuberosum ARF) genes from potato and found that they are unevenly distributed in all the potato chromosomes except chromosome X. Sequence alignment and conserved motif analysis suggested the presence of all typical domains in all but StARF18c that lacks B3 DNA-binding domain. Phylogenetic analysis indicated that potato ARF could be clustered into 3 distinct subgroups, a result supported by exon-intron structure, consensus motifs, and domain architecture. In silico expression analysis and quantitative real-time PCR experiments revealed that several StARFs were expressed in tissue-specific, biotic/abiotic stress-responsive or hormone-inducible manners, which reflected their potential roles in plant growth, development or under various stress adaptions. Strikingly, most StARFs were identified as highly abiotic stress responsive, indicating that auxin signaling might be implicated in mediating environmental stress-adaptation responses. Taken together, this analysis provides molecular insights into StARF gene family, which paves the way to functional analysis of StARF members and will facilitate potato breeding programs.

In eukaryotic cells, nucleocytoplasmic trafficking of macromolecules is largely mediated by Karyopherin β/Importin (KPNβ or Impβ) nuclear transport factors, and they import and export cargo proteins or RNAs via the nuclear pores across the nuclear envelope, consequently effecting the cellular signal cascades in response to pathogen attack and environmental cues. Although achievements on understanding the roles of several KPNβs have been obtained from model plant Arabidopsis thaliana, comprehensive analysis of potato KPNβ gene family is yet to be elucidated. In our genome-wide identifications, a total of 13 StKPNβ (Solanum tuberosum KPNβ) genes were found in the genome of the doubled monoploid S. tuberosum Group Phureja DM1-3. Sequence alignment and conserved domain analysis suggested the presence of importin-β N-terminal domain (IBN_N, PF08310) or Exporin1-like domain (XpoI, PF08389) at N-terminus and HEAT motif at the C-terminal portion in most StKPNβs. Phylogenetic analysis indicated that members of StKPNβ could be classified into 16 subgroups in accordance with their homology to human KPNβs, which was also supported by exon-intron structure, consensus motifs, and domain compositions. RNA-Seq analysis and quantitative real-time PCR experiments revealed that, except StKPNβ3d and StKPNβ4, almost all StKPNβs were ubiquitously expressed in all tissues analyzed, whereas transcriptional levels of several StKPNβs were increased upon biotic/abiotic stress or phytohormone treatments, reflecting their potential roles in plant growth, development or stress responses. Furthermore, we demonstrated that silencing of StKPNβ3a, a SA- and H₂O₂-inducible KPNβ genes led to increased susceptibility to environmental challenges, implying its crucial roles in plant adaption to abiotic stresses. Overall, our results provide molecular insights into StKPNβ gene family, which will serve as a strong foundation for further functional characterization and will facilitate potato breeding programs.

Sulfate transporters (SULTRs) are key players that regulate sulfur acquisition and distribution within plants, thereby influencing cellular redox hemostasis under pathogen attacks, such as Alternaria brassicicola (Ab). In this study, a total of 23 BolSULTR (Brassica oleracea SULTR) genes were identified from the Brassica genome. These BolSULTRs are distributed across nine chromosomes, with all collinear BolSULTR gene pairs undergoing purifying selections. Phylogenetic analysis reveals that the SULTR family is evolutionarily conserved among plant kingdoms. qRT-PCR analysis demonstrated that the expression of BolSULTRs varies across different plant organs and is modulated by hormonal signals. Furthermore, transcriptome analysis identified several BolSULTRs whose expression levels were depressed in Ab-challenged leaves in broccoli. Among them, the BolSULTR2;1 gene emerged as a key player in the plant’s response to Ab. Virus-induced gene silencing (VIGS) of BolSULTR2;1s resulted in elevated glutathione (GSH) levels and enhanced tolerance to Ab. Taken together, these findings underscore the role of BolSULTR2;1 in maintaining redox homeostasis and enhancing plant disease resistance, suggesting its potential as a target for genome editing to develop broccoli varieties with improved pathogen tolerance.

Fungal leaf anthracnose, caused by Colletotrichum species, is a major leaf disease of rubber trees, significantly reducing global natural rubber yields. To explore sustainable and safe biological control strategies, eight bacterial strains were isolated from rubber tree tissues, demonstrating antagonistic activity against Colletotrichum pathogens (C. siamense and C. australisinense). Among these, WSR1 exhibited the most pronounced antifungal effect, with inhibition rates of 87.64% and 89.03% against C. siamense and C. australisinense, respectively. Genomic analysis identified WSR1 as Bacillus velezensis. In pot experiments, WSR1 exhibited preventive efficacy of 77.24% and 73.42% for C. siamense and C. australisinense induced anthracnose, respectively, with therapeutic efficacy of 42.28% and 45.57%. WSR1 compromised the integrity of the cell walls and membranes of both C. siamense and C. australisinense, while inducing reactive oxygen species (ROS) accumulation within the hyphae. Additionally, WSR1 enhanced rubber tree resistance to anthracnose by activating defense-related enzymes, including phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD). Plate assays and genomic analysis revealed that WSR1 secretes fungal cell wall-degrading enzymes (cellulases, pectinase, and protease) and siderophores. Furthermore, LC-MS and gene cluster analysis confirmed the synthesis of antagonistic secondary metabolites, such as surfactin, macrolactin H, and fengycin. This study represents the first identification of Bacillus velezensis as a potential biocontrol agent against rubber tree anthracnose, offering a promising candidate for the eco-friendly management of rubber tree diseases.

Potato early blight (EB), caused by Alternaria, is an economically devastating fungal disease affecting global potato production. Using a hybrid population derived from distantly related varieties, we combined resistance evaluation, histological analysis, Bulked Segregant Analysis sequencing, RNA sequencing and molecular dynamics simulation, which successfully identified key candidate resistance genes. Genetic mapping localized three major resistance-associated regions on chromosome 8 spanning positions 25.07–29.20 Mb, 38.05–38.80 Mb, and 39.40–40.78 Mb. Through candidate gene analysis, we identified CND41, encoding an aspartic protease, as the prime candidate. This gene exhibited significantly higher basal expression levels and stronger pathogen-induced upregulation in resistant genotypes. Molecular dynamics simulations further identified six crucial non-synonymous mutations in the TAXI-N domain that likely contribute to enhanced resistance by destabilizing the susceptibility-associated protein conformation. Transient overexpression of CND41 provided functional evidence supporting its likely involvement in early blight resistance (EBR). These findings contribute valuable genetic resources and a strong candidate gene for molecular breeding toward EBR potato varieties.