Toxin–antitoxin (TA) systems, which are prevalent in bacteria and archaea, play diverse roles in bacterial physiology and have been proposed to be significant in stress adaptation.  Despite the extensive characterization of numerous TA systems in various bacteria, the investigation of these systems within Streptococcus suis is still limited.  Here, we systematically analyzed the type II TA systems of 95 S. suis genomes available in the GenBank database using TAfinder.  A total of 612 putative type II TA systems were retrieved and classified into 10 categories by phylogenetic analysis.  Notably, an elevated occurrence of these TA systems was observed among the important prevalent serotypes 2, 4, 5, 9, 14, Chz, NCL1, and NCL3 strains.  The following study identified the activities of TA systems using 2 strategies and confirmed the regulatory effect of HigBA on the type VII secretion system in S. suis by measuring β-galactosidase activity and transcriptional changes.  Moreover, we unveiled a hitherto uncharacterized, highly prevalent novel TA system, with the composition of antitoxin–toxin–antitoxin (SS-ATA), which regulates the downstream two-component signaling system.  Altogether, this study systematically analyzed the type II TA systems within S. suis, highlighting the widespread distribution of HigBA and SS-ATA as important regulatory elements in S. suis.

Global warming is primarily characterized by asymmetric temperature increases, with greater temperature rises in winter/spring and at night compared to summer/autumn and the daytime.  We investigated the impact of winter night warming on the top expanded leaves of the spring wheat cultivar Yangmai 18 and the semi-winter wheat cultivar Yannong 19 during the 2020–2021 growing season.  Results showed that the night-time mean temperature in the treatment group was 1.27°C higher than the ambient temperature, and winter night warming increased the yields of both wheat cultivars, the activities of sucrose synthase and sucrose phosphate synthase after anthesis, and the biosynthesis of sucrose and soluble sugars.  Differentially expressed genes (DEGs) were identified using criteria of P-value<0.05 and fold change>2, and they were subjected to Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.  Genes differentially expressed in wheat leaves treated with night warming were primarily associated with starch and sucrose metabolism, amino acid biosynthesis, carbon metabolism, plant hormone signal transduction, and amino sugar and nucleotide sugar metabolism.  Comparisons between the groups identified 14 DEGs related to temperature.  These results highlight the effects of winter night warming on wheat development from various perspectives.  Our results provide new insights into the molecular mechanisms of the response of wheat to winter night warming and the candidate genes involved in this process.

Ethylene response factors 2 (ERF2) are essential for plant growth, fruit ripening, metabolism, and resistance to stress. In this study, the levels of expression of the genes for MdERF2 implicated in the biosynthesis of fruit cuticular wax, composition of wax, and ultrastructure in apple (Malus domestica) were studied by the transfection of apple fruit and/or calli with an MdERF2-overexpression (ERF2-OE) and MdERF2-interference (ERF2-AN) vector. In addition, the direct target genes of MdERF2 related to the biosynthesis of wax were identified using electrophoretic mobility shift assays (EMSAs) and dual-luciferase reporter assays (DLRs). The findings indicated that the levels of expression of the wax biosynthetic genes, including long-chain acyl-CoA synthetase 2 (MdLACS2), Eceriferum 1 (MdCER1), Eceriferum 4 (MdCER4), and Eceriferum 6 (MdCER6) were upregulated by ERF2-OE. In contrast, the levels of expression of these genes were inhibited when MdERF2 was silenced. Furthermore, the overall structure and accumulation of the fruit cuticular wax were influenced by the levels of expression of MdERF2. Treatment with ERF2-OE significantly increased the proportion of alkanes and ketones and reduced the proportion of fatty acids and esters. Additionally, the EMSAs and DLRs demonstrated that MdERF2 could bind directly to GCC-box elements in the promoters of MdLACS2, MdCER1, and MdCER6 to activate their transcription. These results confirm that MdERF2 targets the up-regulation of the levels of expression of MdLACS2, MdCER1, and MdCER6 genes, thereby altering the composition, content, and microstructure of apple epidermal wax.