Soil and water are increasingly at risk of contamination from the toxic heavy metals lead (Pb) and cadmium (Cd). Arabis paniculata (Brassicaceae) is a hyperaccumulator of heavy metals (HMs) found widely distributed in areas impacts by mining activities. However, the mechanism by which A. paniculata tolerates HMs is still uncharacterized. For this experiment, we employed RNA sequencing (RNA-seq) in order to find Cd (0.25 mM)- and Pb (2.50 mM)-coresponsive genes A. paniculata. In total, 4490 and 1804 differentially expressed genes (DEGs) were identified in root tissue, and 955 and 2209 DEGs were identified in shoot tissue, after Cd and Pb exposure, respectively. Interestingly in root tissue, gene expression corresponded similarly to both Cd and Pd exposure, of which 27.48% were co-upregulated and 41.00% were co-downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that the co-regulated genes were predominantly involved in transcription factors (TFs), cell wall biosynthesis, metal transport, plant hormone signal transduction, and antioxidant enzyme activity. Many critical Pb/Cd-induced DEGs involved in phytohormone biosynthesis and signal transduction, HM transport, and transcription factors were also identified. Especially the gene ABCC9 was co-downregulated in root tissues but co-upregulated in shoot tissues. The co-downregulation of ABCC9 in the roots prevented Cd and Pb from entering the vacuole rather than the cytoplasm for transporting HMs to shoots. While in shoots, the ABCC9 co-upregulated results in vacuolar Cd and Pb accumulation, which may explain why A. paniculata is a hyperaccumulator. These results will help to reveal the molecular and physiological processes underlying tolerance to HM exposure in the hyperaccumulator A. paniculata, and aid in future efforts to utilize this plant in phytoremediation.

Bacterial communities are composed of a few abundant taxa (AT) and numerous rare taxa (RT). Rivers serve as connectors between water, sediment, and riparian soil, leading to differences in bacterial communities across these habitats. In this study, we sampled 26 sites along the Wujiang River, a major tributary of the Yangtze River in a karst region of China to systematically target the habitat-specific differences in bacterial communities. We hypothesized that (1) community composition and diversity differ among habitats; (2) AT and RT communities exhibit distinct biogeographic patterns; (3) the community assembly processes differ between AT and RT within and across habitat. Results showed significant differences in bacterial community composition between water and sediment, water and soil, but not between sediment and soil. Sediment and soil had higher species richness and diversity than water, with RT mainly contributing to diversity differences. β-diversity was primarily driven by species turnover. A distance-decay relationship appeared only in water communities, indicating stronger spatial structuring, while sediment and soil communities were mainly shaped by environmental factors. Assembly of AT in sediment and soil was governed by undominated processes (ecological drift), whereas dispersal limitation dominated in water. for RT, homogeneous dispersal prevailed in water, while homogeneous selection was predominant in sediment and soil. these findings advance our understanding of abundant and rare bacterial community assembly across riverine habitats and provide new insights into microbial biogeography in plateau karst aquatic ecosystems.

Maize is an important crop. The cysteine-rich polycomb-like protein (CPP) is crucial for plant development and abiotic stress response. However, few reports have been reported on the function of ZmCPPs. This study conducted bioinformatics and expression analyses of the ZmCPP gene family. Based on the homologous comparison methods, 12 ZmCPPs were identified in the last assembly of maize B73 genome (V5). They were unevenly distributed across six maize chromosomes. Six ZmCPPs formed 3 groups due to segmental but no tandem duplication, indicating segmental duplication as the key driving force of the ZmCPPs family expansion. Homologous evolutionary analysis classified 12 ZmCPPs into three groups, with each containing four members. ZmCPP gene structure and protein motif in the same group were highly conserved. The promoter regions of 12 ZmCPP genes containing plant growth, hormone, and abiotic stress-responsive elements. RNA-seq data indicated that the expression pattern of ZmCPPs exhibited organizational specificity and the ZmCPPs transcript levels could be influenced by abiotic/biotic stresses. RT-qPCR analysis of six ZmCPPs (ZmCPP2/4/8/9/11/12) showed that the expression of ZmCPPs were induced or reduced by short-term heat, cold, dehydration, and waterlogging stresses. Furthermore, ZmCPP2/9 was localized in the cytoplasm and nucleus, without transactivation activity in yeast. Taken together, the comprehensive analysis of ZmCPPs in the whole genome provides a novel perspective on the evolutionary relationship among ZmCPP genes and lays a foundation for further study of the biological functions of ZmCPPs.

Tea plants, as essential health beverages, are widely recognized for their rich content of antioxidant metabolites. This study utilized metabolomics analysis techniques to compare the metabolic differences between Camellia tachangensis F. C. Zhang, Camellia gymnogyna Hung T. Chang, and Camellia sinensis (L.) O. Kunzte, aiming to reveal their potential antioxidant activities. By applying UPLC–MS/MS technology, we analyzed metabolites in the samples and identified 1056 metabolites. We utilized statistical methods such as orthogonal partial least squares discriminant analysis (OPLS‐DA) and principal component analysis to evaluate and compare the variations in the samples. An intersection analysis of metabolites from the three types of tea plants identified 29 major differential metabolites. Functional annotation and pathway analysis of these differential metabolites were conducted, ultimately discussing 24 antioxidant‐related metabolites, primarily belonging to flavonoids, phenolic acids, and other categories. Among the three types of tea, C. tachangensis has the highest content of procyanidin B4, which is the most abundant substance in this tea. In terms of the impact of this substance on tea, it is known to have antioxidant properties and contributes to the overall antioxidant capacity of tea. In both C. gymnogyna and C. sinensis, the top 5 antioxidant metabolites include substances such as apigenin‐6,8‐di‐C‐glucoside (vicenin‐2), epigallocatechin, and apigenin‐5‐O‐glucoside. These substances belong to the flavonoid class and contribute to the antioxidant properties of these teas. Beyond the flavonoids and phenolic acids, other classes of metabolites in tea plants also exhibited significant antioxidant properties. These different metabolites play a key role in the antioxidant function of tea, contributing to their potential health benefits. The metabolites provide crucial insights for exploring and developing high‐antioxidant products that occur naturally.