生命科学最新文献

Rosa roxburghii Tratt. is a high-elevation fruit shrub with strong ultraviolet-B (UV-B) tolerance, and plant sterols are critical for its UV-B adaptation, but their regulatory mechanisms remain unknown. Here, we identified a key oxidosqualene cyclase gene, RrOSC5, which encodes a functional cycloartenol synthase and is dynamically upregulated under UV-B stress. Overexpression of RrOSC5 enhanced sterol accumulation in both native and transgenic hosts, significantly improving their UV-B resistance. We further discovered that the transcription factor RrNAC2 directly binds to a non-canonical AC-rich repeat within the RrOSC5 promoter, activating its transcription. Crucially, heterologous overexpression of RrNAC2 in tobacco conferred the enhanced UV-B tolerance, establishing its role as a core regulator in this pathway. Notably, we found that the master UV-B signalling regulator RrHY5 physically interacts with RrNAC2, thereby integrating the RrNAC2-RrOSC5 sterol module Into the canonical UV-B signalling pathway. Our findings revealed a hierarchical RrHY5-RrNAC2-RrOSC5 cascade governs UV-B-induced sterol defence, wherein RrNAC2 drives protective sterol biosynthesis via RrOSC5, and both components synergistically enhance antioxidant and osmotic adjustment defences. This work provides novel insights into sterol-mediated plant adaptation to UV-B stress for molecular breeding of fruit plants.

Inorganic phosphate (Pi) uptake and translocation are crucial for plant growth and development, relying on the plasma membrane targeting of PHOSPHATE TRANSPORTER1 (PHT1) transporters. The plant-specific endoplasmic reticulum (ER)-resident PHOSPHATE TRANSPORTER TRAFFIC FACILITATOR1 (PHF1) is structurally related to SEC12, which initiates the coat protein complex II (COPII) assembly as a guanine nucleotide exchange factor (GEF) by activating the small GTPase SAR1. In contrast, PHF1 loses the conserved catalytic residues critical for GEF activity and specifically assists the ER exit of the PHT1 transporters. However, the underlying molecular mechanism remains unknown. In this study, we showed that overexpression of Arabidopsis thaliana PHT1;1 (AtPHT1;1) in the tobacco relative Nicotiana benthamiana transient expression system caused a portion of AtPHF1 to distribute into AtSAR1b- and AtSEC24a-labelled ER exit sites (ERES). We demonstrated that AtPHF1 interacts with AtSAR1b and AtSAR1c based on tripartite split-GFP association in agro-infiltrated N. benthamiana leaves and verified this interaction using miniTurbo-based proximity labelling. We also confirmed its physiological relevance by co-immunoprecipitating endogenous AtPHF1 with AtSAR1c-GFP in Arabidopsis transgenic lines. Importantly, AtPHF1 preferentially interacts with GDP-locked AtSAR1. Therefore, we propose that AtPHF1 or the AtPHT1;1-AtPHF1 complex interacts with SAR1 GTPase to participate in the early step of COPII assembly for the ER export of PHT1 transporters.

Extremophile Apocynum species hold significant economic and ecological value in arid regions. Deciphering their genetic variation is therefore essential for understanding geographic adaptation to abiotic stresses. Here, we assembled a high-quality genome of Apocynum pictum, and, through comparison with the A. venetum genome, identified abundant genome-wide structural variations, particularly tandem gene duplications (TDs). For instance, a key TD spanning 19 tandem SRP genes was found in A. pictum, compared to only four in A. venetum. We further performed whole-genome resequencing of 280 individuals from natural populations of A. venetum and A. pictum that were widely distributed across arid and saline-alkali regions in northern China. We revealed a distinct geographical distribution of six genetic population clusters in the current landscape. Demographic inference identified a severe population decline during the Last Glacial Maximum, while genetic offset analysis forecasted high vulnerability to future climate change in the mountains and Tarim Basin for both species. TDs, for example, tandemly duplicated LRR-RLK, ABCG, and TLP genes, were under significant selection, as revealed by both selective sweep analysis between A. venetum and A. pictum and genome-environment association analysis with temperature and precipitation variables. TLP overexpression in tobacco enhanced drought tolerance by alleviating oxidative damage. Furthermore, a dual-luciferase assay confirmed that the A. pictum TLP promoter haplotypes carrying selection signals exhibited higher transcriptional activity than their counterparts in A. venetum. Our findings highlighted the combined roles of gene dosage effects and regulatory sequence selection of frequent stress-resistant TDs in harsh environments.

The FLOWERING LOCUS T/TERMINAL FLOWER 1 (FT/TFL1) gene family, a key branch of the phosphatidylethanolamine-binding protein (PEBP) superfamily, is widely recognised as a central regulatory module controlling flowering time and inflorescence architecture in plants. Although FT/TFL1 members share highly conserved structural features, they exhibit remarkable functional divergence. The FT generally promotes floral induction, whereas TFL1 delays or represses it, forming an antagonistic regulatory balance. However, increasing evidence from comparative genomics and molecular studies suggests that the classical 'FT activator/TFL1 repressor' paradigm cannot adequately account for the complex behaviours of expanded gene families across diverse species, tissue types, and environmental conditions. In this review, FT/TFL1 copy-number variation and expansion patterns during plant evolution are synthesised, mechanisms of functional diversification are summarised, and insights from protein interaction rewiring and environmental signal integration are integrated. A unified framework for understanding the evolutionary and environmental shaping of FT/TFL1 is provided, offering theoretical guidance for future studies on reproductive development, adaptive evolution, and applied manipulation of flowering traits.

Vesicle trafficking and ion transport are two fundamental processes that coordinate plant growth, development and stress responses. Under environmental stresses, vesicular trafficking regulates the localisation, activity, recycling, and degradation of ion transporters, which, in turn, take vital part in maintaining osmotic, ionic and pH homoeostasis required for vesicle formation, sorting, and fusion. This review outlines the major vesicular trafficking pathways, vesicle types, and the key regulatory proteins involved in vesicle trafficking. It also provides an in-depth discussion on how vesicle trafficking interacts with ion transport systems during nutrient imbalance, heavy metal toxicity, salt stress, drought, osmotic stress, and pH disturbance. Across these abiotic stress regimes, recurring regulatory principles emerge, including post-translational modification-dependent transporter sorting, TGN/EE-centred cargo decision-making, SNARE-mediated coupling of vesicle fusion with channel activity, and feedback regulation between ion gradients and membrane trafficking. We propose that the crosstalk between vesicle trafficking and ion transport constitutes a dynamic cellular framework that enables plants to integrate environmental signals with ion homoeostasis and developmental plasticity. The synthesis advances our understanding of vesicle trafficking functions and ion transporters regulatory pathways, providing a comprehensive reference for research in this field.

Drought and soil salinization increasingly co‑occur, threatening global food security, particularly in dryland farming systems where these stresses can interact additively, synergistically or antagonistically to reduce crop yields. This review critically distinguishes these interaction types and moves beyond single‑stress frameworks to provide a multiscale synthesis of plant responses, soil water-salt dynamics, root‑system plasticity, rhizosphere microbiome modulation, emerging breeding modelling and agronomic tools. This review provides a detailed overview of the multilevel damage from these co-occurring stresses, including osmotic shock, ionic toxicity and systemic oxidative damage, and examines plant strategies such as ion homoeostasis, osmotic adjustment and antioxidant responses. Beyond plant-centric views, the review explores epigenetic reprogramming for stress memory and the potential of rhizosphere microbiome engineering with plant growth-promoting rhizobacteria as a biological stress-alleviation strategy. It critically examines how high-throughput multiomics techniques, combined with innovative breeding methods, provide a transformative approach to decode complex tolerance traits and accelerate cultivar development. These techniques cover genomics, epigenomics, transcriptomics, proteomics and metabolomics, while the breeding methods include genomic selection and CRISPR-Cas gene editing. Despite progress, key challenges remain: validating combined stress resilience under field conditions, harnessing epigenetic inheritance and integrating microbial solutions into breeding pipelines. We propose a unified framework that merges mechanistic discovery, microbiome-assisted breeding, soil and water management and systems-level predictive modelling. This integrative approach is essential for developing climate-resilient crops to sustain dryland agriculture.

The cereal cyst nematode (Heterodera filipjevi) is a highly destructive pathogen responsible for significant annual economic losses. However, its effector repertoire and functions remain poorly resolved. We assembled stage-resolved transcriptomic data, prioritized secreted candidates, and validated their expression, localization, and functions. Seven candidate effectors were up-regulated at parasitism stages; in situ hybridization detected three effectors in subventral oesophageal glands and four in the dorsal oesophageal gland. Transient expression indicated that seven proteins were located in the nucleus and cytoplasm. In vitro RNAi and in planta RNAi demonstrated virulence roles for seven genes, which reduced female numbers by 28.4%-83.8% and 57.2%-87.2%, respectively. In ROS burst assays, Hf70514 and Hf107644 suppressed flg22-induced reactive oxygen species. Overexpression of Hf70514 in Arabidopsis thaliana increased the root length and plant height. Protein-protein interaction tests identified TaCYPA-1 as a wheat target of Hf70514. Transient silencing of TaCYPA-1 significantly enhanced H. filipjevi parasitism, accompanied by down-regulation of defence-related genes. Collectively, these findings expand the H. filipjevi effector compendium and suggest a model in which multiple secreted effectors suppress the PTI-associated ROS, influence plant growth, and engage specific wheat proteins to promote parasitism.