Xian Sheng Zhang

Summary: Polycomb group (PcG) proteins serve as pivotal epigenetic repressors that govern the transcriptional programs underlying cell growth and differentiation. However, their functional roles in maize endosperm remain largely unexplored. Here, we characterize the recessive maize small‐kernel mutant sks1 , which exhibits persistent endosperm cell hyperproliferation and compromised cell expansion during grain filling. Map‐based cloning reveals that SKS1 encodes ZmEMF1a, a PcG protein that physically interacts with subunits of both PRC1 and PRC2. Integrated ChIP‐seq and RNA‐seq analyses were performed to investigate its epigenetic regulatory functions. ZmEMF1a orchestrates a stage‐specific epigenetic regulatory program: it predominantly mediates H3K27me3 deposition at 6 d after pollination (DAP), while coordinately regulating the deposition of both H3K27me3 and H2Aub1 at 10 DAP. Loss of ZmEMF1a leads to ectopic hyperproliferation of differentiated endosperm tissues, specifically the basal endosperm transfer layer (BETL) and aleurone (AL), as well as elevated vitamin B content in the endosperm. Collectively, these findings establish ZmEMF1a as an epigenetic regulator that balances endosperm proliferation, cell fate specification, and nutrient accumulation through stage‐specific histone modifications, thereby offering promising targets for enhancing maize yield and nutritional quality.

Sexual reproduction in plants is a tightly coordinated process that underpins biodiversity, drives speciation, and serves as a foundation for modern crop improvement. Here, we synthesize recent advances in elucidating the molecular mechanisms governing major reproductive events in flowering plants, including male and female gametogenesis, pollen-pistil communication, double fertilization, embryogenesis, and endosperm-mediated seed development. We also discuss the integration of asexual propagation through protoplast regeneration, highlighting its emerging importance in plant biotechnology. Together, these insights deepen our understanding of fundamental reproductive biology and open new opportunities for the rational design of hybrid breeding systems and stress-resilient crops, with broad implications for global food security under changing climatic conditions.

A systematic evaluation of salt tolerance at the seedling stage was conducted using 143 maize inbred lines under a 150 mM mixed-salt solution (NaCl:Na₂SO₄ = 9:1, EC = 16.78 dS/m) that mirrors the ionic composition of saline groundwater in the Yellow River Delta. The comprehensive salt tolerance index (D value) ranged from 0.15 to 0.85 across the population, with the elite line B114 exhibiting the highest D value (0.835) and the sensitive line PHT55 ranking near the bottom. Under salt stress, B114 displayed remarkable growth stability, with plant height decreasing by only 25.9%, fresh weight by 13.3%, and dry weight remaining unchanged, whereas PHT55 suffered severe growth inhibition (plant height: 61.5% decrease; fresh weight: 63.2% decrease; dry weight: 33.3% decrease). Time-series RNA-seq of root tissues across four time points (5, 8, 11, and 14 days) revealed markedly distinct transcriptional dynamics: B114 exhibited relatively stable temporal regulation (2261–9124 DEGs), whereas PHT55 showed a pronounced early transcriptional burst that progressively intensified (3728–10,108 DEGs). Using random forest-based machine learning, 50 core salt tolerance-related genes were unbiasedly identified from 16,194 significantly differentially expressed genes. Functional enrichment analysis revealed that these genes were primarily involved in redox regulation, ion homeostasis maintenance, and stress signal transduction pathways. qRT-PCR validation confirmed biphasic expression patterns, with Zm00001d024160 showing the strongest early induction (48-fold at 5 h). This study established a maize salt tolerance evaluation system closely aligned with field conditions and demonstrated that coordinated temporal transcriptional regulation represents a core molecular mechanism underlying high salt tolerance in maize. The elite salt-tolerant germplasm and key candidate genes identified here provide valuable genetic resources and a theoretical foundation for molecular breeding of salt-tolerant maize adapted to saline-alkaline soils.

Soil salinization is a major abiotic stress limiting wheat production. Although transcriptional responses to salt stress are well-studied, the role of post-transcriptional regulation, particularly through RNA modifications, remains unclear in wheat (Triticum aestivum L.). Here, we present an integrated analysis of the early salt stress response using Nanopore direct RNA sequencing (DRS) and quantitative proteomics. We generated genome-wide maps of N6-methyladenosine (m6A) modifications, concurrently profiling alternative polyadenylation (APA) events and poly(A) tail length (PAL) dynamics. This multi-omics approach characterizes coordinated epitranscriptomic reprogramming and enabled the construction of a regulatory network linking m6A marks to proteomic changes. Furthermore, we identified and functionally validated the putative m6A reader protein TaECT5 as a positive regulator of wheat salt tolerance. Our study provides a systems-level view of post-transcriptional regulation during salt stress in wheat and identifies potential targets for enhancing salt tolerance.

A systematic evaluation of salt tolerance at the seedling stage was conducted using 143 maize inbred lines in this study. The results showed that salt stress significantly inhibited seedling growth and enabled the identification of several elite salt-tolerant inbred lines, including B114. Salt tolerance was significantly positively correlated with anti-oxidant capacity. Under salt stress, the highly salt-tolerant line B114 exhibited lower membrane damage, stronger reactive oxygen species scavenging capacity, and a significantly higher survival rate than the salt-sensitive line PHT55. Using random for-est-based machine learning, 50 core salt tolerance-related genes were unbiasedly identified from high-dimensional transcriptomic data. Functional enrichment analysis revealed that these genes were primarily involved in redox regulation, ion homeostasis maintenance, and stress signal transduction pathways. This study established a maize salt tolerance evaluation system closely aligned with field conditions and demonstrated that coordi-nated temporal transcriptional regulation represents a core molecular mechanism under-lying high salt tolerance in maize. The elite salt-tolerant germplasm and key candidate genes identified in this study provide valuable genetic resources and a theoretical founda-tion for molecular breeding of salt-tolerant maize adapted to saline-alkaline soils.

Key message: TaDJA-6D boosts wheat regeneration and transformation efficiency across genotypes, offering a new molecular breeding resource. As a key member of the heat shock protein 40 family, the co-chaperone DnaJ proteins play a crucial role in plant growth, development, and stress responses. However, very few studies have focused on the function of DnaJ protein in wheat ( Triticum aestivum L.). Here, we characterized a DnaJ family gene from wheat, TaDJA-6D , ( TraesCS6D02G232600 ) and analyzed its spatiotemporal expression pattern. During wheat regeneration, the transcriptional expression level of the TaDJA-6D gene was continuously upregulated with the extension of tissue culture time; in situ hybridization revealed that the genes were highly expressed in the vigorously dividing regions of wheat calli. Functional analysis demonstrated that, compared with the control vector, overexpression of TaDJA-6D significantly improved the wheat regeneration and transformation efficiency across diverse wheat genotypes, including Fielder, Kenong 199, Yanda 1817 and Xiaoyan 6. Our findings suggest that TaDJA-6D plays an important role in the process of wheat regeneration and genetic transformation. This study deepens our understanding of the functions of wheat co-chaperone proteins and provides novel genetic resources for efficient wheat transformation.

In the root apical meristem, the stem cell niche (SCN) comprises a mitotically inactive quiescent center (QC) and adjacent, mitotically active stem cells that divide to form root tissues. Auxin dynamics are essential for specification and maintenance of the root SCN; however, the underlying mechanisms remain to be explored. Here, we report that Arabidopsis (Arabidopsis thaliana) AUXIN RESPONSE FACTOR3 (ARF3), ARF3-INTERACTING PROTEIN1/2 (AIP1/2), and SIN3-ASSOCIATED POLYPEPTIDE OF 18 KDA (SAP18) form a protein complex that specifies root SCN cell fate in response to auxin level. In cells proximal to the QC, the ARF3-AIP1/2-SAP18 complex bound the WOX5 promoter and restricted WOX5 expression to the QC by decreasing H3 histone acetylation, thereby maintaining the SCN. Disrupting the ARF3-AIP1/2-SAP18 complex via mutation or exposure to excessive amounts of auxin resulted in proximal and lateral expansion of WOX5 expression and inhibited root elongation by repressing cell division. During de novo specification of the SCN in lateral root primordia or regenerating root tips, accumulated auxin caused the ARF3-AIP1/2-SAP18 complex to dissociate, allowing the induction of WOX5 expression. In the reestablished meristem, the ARF3-AIP1/2-SAP18 complex confines WOX5 expression to the newly formed QC. Our findings provide insights into the roles of auxin dynamics in determining root SCN.

The FAcilitates Chromatin Transcription (FACT) complex, comprising structure-specific recognition protein 1 (SSRP1) and suppressor of Ty 16 (SPT16), plays a key role in regulating gene transcription by facilitating ATP-independent nucleosome assembly. SSRP1 contains an HMG domain that binds to DNA and regulates cell proliferation, apoptosis, and DNA repair. However, its role in plant development remains poorly understood. In this study, we identified a mutant, small kernel 301 (smk301), characterized by reduced kernel size and semi-dwarfism. Map-based cloning revealed that the mutation affects ZmSSRP1 on chromosome 8, which is expressed throughout maize (Zea mays L.) tissues. ZmSSRP1 localizes to the nucleus and interacts with ZmSPT16 to form the FACT complex. Using RNA-seq and ATAC-seq analyses, we identified 3 candidate target genes involved in hormone pathways, all of which show a significant positive correlation with ZmSSRP1 expression. Notably, ZmSSRP1 was enriched in the chromatin open region of brassinosteroid-deficient dwarf 1 (ZmBRD1), which encodes a Brassinosteroid C-6 Oxidase. This indicates that ZmSSRP1 affects maize development by regulating the transcription of ZmBRD1, thereby influencing the brassinosteroid content in maize. Our findings shed light on how the FACT complex influences maize development by modulating the expression of brassinosteroid-related genes, offering insights into the molecular mechanisms underlying plant growth.

Despite significant advancements in chemotherapy, treatment efficacy remains limited by drug resistance and toxicity. Anticancer agents from natural sources have been proven in terms of potency, efficiency, and safety. Among them, fungi have emerged as the largest contributor to the field of medicine. However, many fungal bioactive compounds remain underexplored due to their structural and ecological diversity. This review highlights the research progress on products, functions, and therapeutic mechanisms of anticancer fungi identified during 2015–2025. Furthermore, this review provides a novel integrative perspective by comprehensively comparing three diverse categories of fungi, including endophytic, marine and edible fungi. Although various anticancer metabolites have been reported from edible and marine fungi, only a few have reached the market primarily due to low metabolite yields and limited clinical, toxicity, and pharmacokinetic data. This review focused on the most potent anticancerous metabolites, fungal extracts and their biological activities from 3 categories of fungi against the common cancer cell lines, indicating endophytic fungi as the biggest source of anticancerous metabolites. Anticancer mechanisms involved are the production of ROS, damage to mitochondrial membrane, inhibition of microtubule formation, caspase 3/9 pathway activation, and macrophage-based actions.