Structural features important for the U12 snRNA binding and minor spliceosome assembly of Arabidopsis U11/U12-small nuclear ribonucleoproteins.

Although seven proteins unique to U12 intron-specific minor spliceosomes, denoted as U11/U12-65K, -59K, -48K, -35K, -31K, -25K, and -20K, have been identified in humans and the roles of some of them have been demonstrated, the functional role of most of these proteins in plants is not understood. A recent study demonstrated that Arabidopsis U11/U12-65K is essential for U12 intron splicing and normal plant development. However, the structural features and sequence motifs important for 65 K binding to U12 snRNA and other spliceosomal proteins remain unclear. Here, we demonstrated by domain-deletion analysis that the C-terminal region of the 65 K protein bound specifically to the stem-loop III of U12 snRNA, whereas the N-terminal region of the 65 K protein was responsible for interacting with the 59 K protein. Analysis of the interactions between each snRNP protein using yeast two-hybrid analysis and in planta bimolecular fluorescence complementation and luciferase complementation imaging assays demonstrated that the core interactions among the 65 K, 59 K, and 48 K proteins were conserved between plants and animals, and multiple interactions were observed among the U11/U12-snRNP proteins. Taken together, these results reveal that U11/U12-65K is an indispensible component of the minor spliceosome complex by binding to both U11/U12-59K and U12 snRNA, and that multiple interactions among the U11/U12-snRNP proteins are necessary for minor spliceosome assembly.

Shotgun metagenomic dataset of root endophytic microbiome of citrus (Citrus nobilis L.).

Citrus (Citrus nobilis L.) is one of the main fruit crops in Dak Lak Province of Vietnam; however, a dataset on the endophytic microbiome of this plant has yet to be discovered. This article presented the endophytic microbial dataset from roots of healthy Citrus nobilis L. collected in Dak Lak for the first time. We found that 4 kingdoms, 30 phyla, 58 classes, 125 orders, 242 families, 722 genera, and 1637 species of endophytic microorganisms were identified from the sample. Actinomycetota was shown to be the main phylum (64.36 %) and biosynthesis to be the most abundant function (55.64 %) of the endophytic microbial community. Data provided insights into the composition and functional diversity of the Citrus nobilis L. endophytic microbiome, especially novel microbial resources. They could be used for the next works towards applying the endophytic microbiome for sustainable citrus production.

Enhancing the antibacterial activity of ampicillin loaded into chitosan/starch nanocomposites against AMR Staphylococcusaureus.

Ampicillin (Amp), an antibiotic, is widely used to treat bacterial infections in humans and livestock, but recently the rate of resistance has increased rapidly. The aim of this work was to enhancing the antibacterial effect of this compound against AMR Staphylococcus aureus via loading Amp into chitosan/starch nanocomposites by spray drying technique. The results showed that the different ratio of chitosan gel and starch gel used in preparing the nanocomposites can affect its properties and performance. The size distribution of the nanocomposite particles was ranging from 122.0 to 816.9 nm. The zeta potential values of the nanocomposites range from +29.47 to +93.07 mV, indicating the stability of the particles and their tendency to repel each other. Ampicillin was loaded into the chitosan/starch nanocomposites with encapsulation efficiency of 70.7-77.3 %, then their releasing and antibacterial effect against AMR S. aureus were investigated. The results indicated that antibacterial activity of chitosan/starch nanocomposites loaded ampicillin was much higher than ampicillin alone. Chitosan/starch nanocomposites loaded ampicillin at concentration 5.0 µg/mL inhibited 88.6 % growth of S. aureus to a similar extent as 7.5 µg/mL of ampicillin alone. Additionally, at same 7.5 µg/mL ampicillin concentration, the nanocomposites loaded ampicillin showed a higher inhibitory rate (93.27 %) compared to ampicillin alone (88.96 %) over a 12 h-period. Especially, the antibacterial activity of chitosan/starch nanocomposites loaded ampicillin still maintained their effectiveness over 48 h (95.43 %) while those the ampicillin decreased down to 85.76 %. This research highlights the potential of using the chitosan/starch nanocomposites as nanocarriers for ampicillin to enhance its antibacterial activity against AMR Staphylococcus aureus. This approach could be a promising strategy to combat antimicrobial resistance.

Abiotic stresses affect differently the intron splicing and expression of chloroplast genes in coffee plants (Coffea arabica) and rice (Oryza sativa).

Despite the increasing understanding of the regulation of chloroplast gene expression in plants, the importance of intron splicing and processing of chloroplast RNA transcripts under stress conditions is largely unknown. Here, to understand how abiotic stresses affect the intron splicing and expression patterns of chloroplast genes in dicots and monocots, we carried out a comprehensive analysis of the intron splicing and expression patterns of chloroplast genes in the coffee plant (Coffea arabica) as a dicot and rice (Oryza sativa) as a monocot under abiotic stresses, including drought, cold, or combined drought and heat stresses. The photosynthetic activity of both coffee plants and rice seedlings was significantly reduced under all stress conditions tested. Analysis of the transcript levels of chloroplast genes revealed that the splicing of tRNAs and mRNAs in coffee plants and rice seedlings were significantly affected by abiotic stresses. Notably, abiotic stresses affected differently the splicing of chloroplast tRNAs and mRNAs in coffee plants and rice seedlings. The transcript levels of most chloroplast genes were markedly downregulated in both coffee plants and rice seedlings upon stress treatment. Taken together, these results suggest that coffee and rice plants respond to abiotic stresses via regulating the intron splicing and expression of different sets of chloroplast genes.