Phytopathogenic fungi can weaken the effectiveness of antifungal chemicals from plants and artificial synthesis through a xenobiotic detoxification system.  Nevertheless, the transcription factors responsible for transcriptional activation of xenobiotic detoxification genes in phytopathogenic fungi are rarely reported.  Here, we show that a GATA transcription factor, SsGATA1, regulates the transcription of drug efflux pump genes, thus contributing to tolerance to various types of chemical fungicides, including propiconazole, caspofungin, and azoxystrobin in Sclerotinia sclerotiorum.  Similarly, SsGATA1 also confers tolerance to isothiocyanate and flavonols, two compounds reported as broad-spectrum antifungal chemicals, by mediating the transcription of the isothiocyanate hydrolase SsSaxA.  Importantly, SsGATA1 positively regulates pathogenicity, which is attributed to the upregulation of hydrolases and SsSaxA during infection.  Furthermore, SsGATA1 is responsible for tolerance to several stresses.  Our findings demonstrate that SsGATA1 plays roles in multidrug resistance and pathogenicity by activating the transcription of hydrolases and xenobiotic detoxification genes.

Filament-like plant proteins are intermediate filament proteins that play a major role in the development and growth of plants.  However, no studies have systematically identified or characterized the filament-like plant proteins (FPP) family in plants.  Fifty-nine FPP candidates were found in this study by analyzing the genomes of two dicots and four monocots.  Phylogenetic analysis and multicollinearity mapping showed the relatively conserved evolution of FPP genes in monocots.  In rice, eight OsFPPs were characterized and found to be induced or repressed by abiotic stresses.  Additional genetic evidence showed that OsFPP7-overexpressing rice exhibited increased sensitivity to abscisic acid during the germination stage, disrupted Na⁺/K⁺ homeostasis, and disrupted balance of reactive oxygen species during the seedling stage when exposed to salt stress.  Conversely, the knockout of osfpp7 alleviated abscisic acid (ABA) sensitivity, safeguarded the antioxidant system and sodium ion transport system, and thus enhanced rice salt tolerance.  In the cytoskeleton, the functions of FPPs in controlling salt stress and plant stress tolerance mechanisms are all further elucidated by our findings.

UBL-UBA protein functions as a shuttle factor in the 26S ubiquitin degradation pathway, playing a critical role in plant growth and development, and responding to various biotic and abiotic stresses.  Although RAD23, a type of UBL-UBA protein, has been extensively studied in several plants, there is currently no comprehensive analysis available for kiwifruit (Actinidia chinensis).  In this study, we identified six AcRAD23 genes in kiwifruit and further analyzed their phylogenetic relationships, gene structure, conserved motif composition and cis-acting element in the promoter.  Subcellular localization experiments revealed that all AcRAD23 were localized in the nucleus and the cell membranes.  Quantitative real-time PCR (qRT-PCR) analysis demonstrated differential expression patterns of these AcRAD23 genes across different tissues and under various stress conditions (drought, waterlogging, salt stress, etc.), with AcRAD23D1 showing the highest responsiveness to abiotic stress.  Additionally, we investigated the biological function of AcRAD23D1 using VIGS-mediated gene silencing methods under drought stress conditions.  Suppression of AcRAD23D1 expression resulted in reduced relative water content (RWC) but increased malondialdehyde (MDA) content and relative electrolyte leakage (REL) levels in D1-VIGS lines compared to control lines.  Furthermore, D1-VIGS lines exhibited a higher accumulation of reactive oxygen species (ROS) along with decreased superoxide dismutase (SOD) and peroxidase (POD) enzyme activities.  These findings suggest that AcRAD23D1 may play a positive role in regulating kiwifruit’s response to drought stress.  Our results provide new insights into the potential involvement of AcRAD23 under abiotic stress conditions while offering a theoretical foundation for understanding the molecular mechanisms underlying kiwifruit’s adaptation to stresses. 

Protein phosphatase type-2Cs (PP2Cs) are widely involved in regulating plant growth and development, cell division, and, importantly, responses to abiotic stresses through reversible protein phosphorylation. We investigated the PP2C gene family in alfalfa through genome-wide identification and expression profiling analysis. Overall, 104 MsPP2C members identified in the alfalfa genome were classified into 13 subfamilies. Phylogenetic relationships, chromosomal distributions, duplication events, gene structures, and conserved motifs of MsPP2Cs were systematically analyzed. Additionally, transcriptomic and real-time quantitative PCR analyses revealed 14 MsPP2C genes were significantly differentially expressed in alfalfa under alkali stress. Among these, MsPP2C8, MsPP2C38, MsPP2C60, MsPP2C62, MsPP2C102, and MsPP2C103 (subfamily A) were rapidly and markedly upregulated in response to alkali stress. KEGG enrichment analysis revealed these genes were involved in plant hormone signal transduction and MAPK signaling pathway. MsPP2C38 had a core regulatory role in a predicted protein-interaction network, and interacted strongly with the proteins WRKY40 and DREB2A. Subcellular localization assays indicated MsPP2C8, MsPP2C38, MsPP2C62, and MsPP2C103 to be localized in the nucleus. These findings improve our understanding of the PP2C family, and clarify the critical regulatory roles of subfamily A members in mediating salt–alkali stress responses and tolerance in alfalfa.

Brucella spp., an intracellular bacterium, uses its type IV secretion system (T4SS) to regulate host signaling pathways and promote intracellular survival, but the molecular mechanism of this process remains largely unknown. Here we found that increasing the abundance of acetylated protein in host cells promotes the intracellular survival of Brucella. Moreover, our results demonstrated that the Brucella effector protein BspF can impact protein acetylation modification in host cells by interacting with other intracellular proteases. We conducted LC-MS/MS to characterize the protein acetylation mediated by BspF. We identified that SNAP29 K103 was acetylated, and that acetylated SNAP29 inhibited its interaction with STX17, thereby regulating the autophagy and providing an environment for the intracellular survival of Brucella. Furthermore, our results provide the first report of a bacterial effector using acetylation to affect the SNAP29-STX17-VAMP8 complex, and inhibit the host's defense system. Our results suggest a vital role of SNAP29 acetylation in autophagy of host cells under intracellular infection, by specifically regulating the assemble of SNARE.