The Na⁺/H⁺ antiporter (NHX) gene family plays a pivotal role in plant salt tolerance in regulating intracellular Na⁺ and H⁺ homeostasis. In this study, seven candidate OsNHX genes (OsNHX1 to OsNHX7) were identified in the rice genome and classified into three phylogenetic clusters (Vac, Endo, and PM) based on their predicted subcellular localization. Five OsNHX gene pairs (OsNHX1/OsNHX2, OsNHX1/OsNHX3, OsNHX1/OsNHX4, OsNHX2/OsNHX6, and OsNHX5/OsNHX6) were found to have arisen from dispersed duplication events and exhibited purifying selection, indicating functional conservation. Analysis of cis-regulatory elements (CREs) revealed a diverse range of elements associated with tissue-specific expression, hormone signaling, and stress responses, particularly to dehydration and salinity. Notably, CREs associated with tissue/organelle-specific expression and stress responses were the most abundant, suggesting a potential role for OsNHX genes in regulating growth, development, and stress tolerance in rice. Importantly, expression profiling revealed that OsNHX1, OsNHX2, OsNHX3, and OsNHX5 were upregulated under salt stress, with significantly higher expression levels in the salt-tolerant rice cultivar Pokkali compared to the salt-sensitive cultivar IR64. Our findings provide a comprehensive analysis of the evolutionary, structural, and functional features of the OsNHX gene family and highlights their critical role in rice salt tolerance, offering insights into potential applications for crop improvement.

Acropora is one of the most common coral genera found in Phu Quoc Islands, Vietnam. However, the presence of marine snails, such as the coralllivorous gastropod Drupella rugosa, was a potential threat to the survival of many scleractinian species, leading to changes in the health status and bacterial diversity of coral reefs in Phu Quoc Islands. Here, we describe the composition of bacterial communities associated with two species of Acropora (Acropora formosa and Acropora millepora) using the Illumina sequencing technology. This dataset includes 5 coral samples of each status (grazed or healthy), which were collected in Phu Quoc Islands (9°55'20.6″N 104°01'16.4″E) in May 2020. A total of 19 phyla, 34 classes, 98 orders, 216 families and 364 bacterial genera were detected from 10 coral samples. Overall, Proteobacteria and Firmicutes were the two most common bacterial phyla in all samples. Significant differences in the relative abundances of the genera Fusibacter, Halarcobacter, Malaciobacter, and Thalassotalea between grazed and healthy status were observed. However, there was no differences in alpha diversity indices between the two status. Furthermore, the dataset analysis also indicated that Vibrio and Fusibacter were core genera in the grazed samples, whereas Pseudomonas was the core genus in the healthy samples.

The role of microorganisms in coral health, disease, and nutrition has been demonstrated in various studies. Environmental factors including pH, temperature, and dissolved oxygen also play crucial roles in maintaining sustainable coral ecosystems. However, how geographical and environmental factors influence bacterial diversity and community composition is unclear. Here, bacterial communities associated with Acropora formosa coral were sampled from four different locations—Phu Quoc Islands (Vietnam), Nha Trang (Vietnam), Ujung Gelam (Indonesia), and Bourake (New Caledonia)—and compared using tagged 16S rRNA sequencing. We identified 24 bacterial phyla, 47 classes, 114 orders, and 495 genera from 18 samples. Overall, Proteobacteria (1039 distant amplicon sequence variants [ASVs]) and Firmicutes (589 ASVs) were predominant, while Verrucomicrobiota (75 ASVs) and Planctomycetota (46 ASVs) were minor taxa. Alpha diversity analyses revealed that the bacterial community associated with Acropora formosa from Ujung Gelam had the highest indexes (Observed and Chao1), while the figures for Bourake were the lowest. Non-metric multidimensional scaling analysis (NMDS) showed significant differences in bacterial communities among locations (ADONIS, p = 1 × 10⁻⁴). Temperature was strongly correlated with the distribution of bacterial communities in Bourake, whereas pH and dissolved oxygen were significantly correlated with the presence of coral-associated bacterial communities in Phu Quoc and Nha Trang. Across all samples, 28 potential biological markers and 95 core ASVs were found, revealing significant differences in coral-associated bacterial communities. Collectively, these findings provide a comprehensive understanding of bacterial communities living in coral reefs across different geographic sites, which could be useful springboards for further studies.

Rice is sensitive to salt stress, but its sensitivity varies among genotypes, indicating natural variation in regulatory mechanisms and genetic makeup. High-affinity potassium transporters (HKTs) that transport cations across membranes play important roles in stress responses of plants. In this study, the gene sequence polymorphisms and expression level of OsHKT1;3 which is a member of the rice HKT gene family was assessed. Sequence analysis indicated 5 single nucleotide polymorphisms (SNPs) in the coding sequence; 4 nucleotide substitutions, one nucleotide deletion and one nucleotide insertion in the promoter region of OsHKT1;3 gene. Among 5 SNPs in the coding sequence, one was non-synonymous (C598G) which caused the change in amino acid L200V and 4 were synonymous substitutions (A798C, G2083A, T2101C, C2122T). The substituted amino acid L200V was predicted to locate in the third transmembrane segment of OsHKT1;3 protein. In the promoter region, 3 nucleotide substitutions at position -879, -453, and -202 caused the change in cis-elements with 8 deletions and 3 additions. Expression levels of OsHKT1;3 were analyzed in the leaves and the roots under 2 different salt concentrations and showed a tendency of reduction in most of the conditions. Keywords: OsHKT1;3, salt stress, rice, polymorphism.

Previous studies have reported the functional role, biochemical features and synthesis pathway of podophyllotoxin (PTOX) in plants. In this study, we employed combined morphological and molecular techniques to identify an endophytic fungus and extract PTOX derivatives. Based on the analysis of ITS sequences and the phylogenetic tree, the isolate was classified as Penicillium herquei HGN12.1C, with a sequence identity of 98.58%. Morphologically, the HGN12.1C strain exhibits white colonies, short‐branched mycelia and densely packed hyphae. Using PacBio sequencing at an average read depth of 195×, we obtained a high‐quality genome for the HGN12.1C strain, which is 34.9 Mb in size, containing eight chromosomes, one mitochondrial genome and a GC content of 46.5%. Genome analysis revealed 10 genes potentially involved in PTOX biosynthesis. These genes include VdtD , Pinoresinollariciresinol reductase ( PLR ), Secoisolariciresinol dehydrogenase ( SDH ), CYP719A23 , CYP71BE54 , O‐methyltransferase 1 ( OMT1 ), O‐methyltransferase 3 ( OMT3 ), 2‐ODD , CYP71CU and CYP82D61 . Notably, the VdtD gene in fungi shares functional similarities with the DIR gene found in plants. Additionally, we identified peltatin, a PTOX derivative, in the HGN12.1C extract. Docking analysis suggests a potential role for the 2‐ODD enzyme in converting yatein to deoxypodophyllotoxin. These findings offer invaluable insights into the synthesis mechanism of PTOX in fungi, shedding light on the relationship between host plants and endophytes.