Beijing University of Agriculture

Soil salinization imposes catastrophic constraints on Malus domestica productivity, primarily through ionic toxicity and osmotic stress that disrupt cellular homeostasis. Salt stress constitutes a primary environmental constraint limiting the geographic distribution, productivity, and yield security of Malus species. Here, we characterize the vacuolar H⁺-ATPases (VHAs) subunit MdVHA-a3 as a master regulator of apple salt adaptation. Systematic analysis revealed that MdVHA-a3 localizes predominantly to the vacuolar membrane, harbors domains highly conserved among plant species, and exhibits elevated expression in young leaves of apple. Moreover, MdVHA-a3 responds transcriptionally to salt stress, and its promoter contains multiple stress-associated cis-acting elements. Transient transformation assays and salt-treated transgenic calli further confirm that MdVHA-a3 significantly enhances salt tolerance in apple seedlings and calli, concomitant with accelerated Na⁺/H⁺ efflux and upregulated expression of key salt tolerance genes. Collectively, MdVHA-a3 mitigates salt stress by regulating H⁺ and Na⁺ ion transport and augmenting antioxidant enzyme activities. This work nominates MdVHA-a3 as a modular breeding chassis for engineering salinity-resilient apple rootstock.

Anther is a key male reproductive organ that is essential for the plant life cycle, from the sporophyte to the gametophyte generation. To explore the isoform-level transcriptional landscape of developing anthers in maize (Zea mays L.), we analyzed Iso-Seq data from anthers collected at 10 developmental stages, together with strand-specific RNA-seq, CAGE-seq, and PAS-seq data. Of the 152,026 high-confidence full-length isoforms identified, 68.8% have not been described; these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes. Using our newly developed strategy to detect dynamic expression patterns of isoforms, we identify 13,899 differentially variable regions (DVRs); surprisingly, 1275 genes contain more than two DVRs, revealing highly efficient utilization of limited genic regions. We identify 7876 long non-coding RNAs (lncRNAs) from 4098 loci, most of which were preferentially expressed during cell differentiation and meiosis. We also detected 371 long-range interactions involving intergenic lncRNAs (lincRNAs); interestingly, 243 were lincRNA-gene ones, and the interacting genes were highly expressed in anthers, suggesting that many potential lncRNA regulators of key genes are required for anther development. This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.

To accurately identify the dynamic distribution of heavy metals （Ni, Cu, Zn, Cd, and Pb） in eutrophic lakes and their response mechanism to environmental changes, the distribution levels of heavy metals in the overlying water and surface sediments of Meiliang Bay in Taihu Lake were analyzed during summer and winter. Additionally, the change characteristics of heavy metals at the sediment-water interface in particular were observed using film diffusion gradient technology （DGT） and high-resolution dialysis technology （HR-Peeper）. The results showed that the average concentrations of five heavy metals both in overlying water and surface sediments generally decreased in the order of Zn>Ni>Cu>Pb>Cd. The concentrations of heavy metals in the overlying water, as well as the bioavailable and dissolved concentrations of heavy metals （c_DGT and c_Peeper） at the sediment-water interface, were generally higher in summer than in winter. The Mantel test showed significant correlations between c_DGT at the sediment-water interface and heavy metal concentrations in overlying water, confirming that heavy metal migration from sediment directly affected the levels of heavy metals in overlying water. Redundancy analysis （RDA） was further used to identify the key environmental factors regulating the dynamic changes of heavy metals at the sediment-water interface, including dissolved oxygen （DO）, chlorophyll-a （Chla）, pH, sediment pH （S_pH）, and sediment redox potential （S_Eh）. Among them, c_DGT-Ni, c_DGT-Cu, c_DGT-Cd, and c_DGT-Pb were mainly positively correlated with Chla and pH, and negatively correlated with S_Eh, S_pH, and DO. This reflects that algal blooms during summer significantly promoted the heavy metal migration from sediment to water.