生命科学最新文献

Loquat (Eriobotrya japonica) regeneration and transformation are difficult, hindering gene function studies. To overcome this limitation, we developed a rapid and stable regeneration and transformation system for hairy roots in loquat by optimising key conditions, in order to explore the potential functions of key genes involved in root growth and development. LEAFY COTYLEDON 2 (LEC2) is a central hub linking embryonic development, lipid synthesis, root system development, and hormonal regulation. However, the role of the LEC2 protein in regulating root growth and development in loquat remains unclear. This study demonstrates a specific interaction between LEC2 and FUSCA3 (FUS3) in loquat, with FUS3 acting downstream of LEC2. Overexpression of LEC2 or FUS3 showed longer root length and increased root numbers, while loss-of-function mutants of either LEC2 or FUS3 exhibited shorter root lengths and reduced root numbers, and overexpression of FUS3 effectively compensated for the root growth defects in LEC2 knockout mutants. In summary, the stable Agrobacterium rhizogenes-mediated transformation system provides an effective approach for gene function analysis and genetic engineering research in loquat, and the LEC2-FUS3 complex functions as a key regulator in auxin-regulated root growth and development.

Here, we evaluated foliar-applied silicon quantum dots (SiQDs) with different surface charges on soybean salt tolerance. Positively charged SiQDs (P-SiQDs) exhibited stronger foliar retention and penetration than negatively charged SiQDs (N-SiQDs), resulting in a 35.3% higher silicon accumulation in leaves. Under 200 mM NaCl stress, foliar application of P-SiQDs increased shoot dry weight and reduced the Na⁺/K⁺ ratio. Compared with N-SiQDs, P-SiQDs more effectively alleviated salt-induced damage to thylakoid ultrastructure and improved photosynthetic performance. A life cycle field pot trial further showed that SiQDs increased the 100-seed weight by 20.1%-25.9% under salt stress. Leaf metabolomics showed significant alterations in lipid metabolite pathways associated with redox homeostasis, accompanied by shifts in the phyllosphere microbiome. P-SiQDs increased the abundance of Chloroflexota, Actinomycetota, and genera such as Paenarthrobacter, Variovorax, and Xanthobacter. Meanwhile, the phyllosphere microbiome shifted toward life-history strategies related to growth, resource acquisition, and salt stress tolerance. In addition, P-SiQDs promoted root growth, nodulation, and nitrogenase activity, leghemoglobin content, and total nitrogen accumulation, together with changes in root exudate composition and the enrichment of salt-tolerant rhizosphere bacteria, including Sphingomonas and Novosphingobium. These findings indicate that surface charge modification is an effective strategy to enhance the efficiency of foliar nano-fertilizer application.

Vegetable cultivation is heavily reliant on an ample water supply, with water deficiency limiting seedling growth and final yield. The phytohormone abscisic acid (ABA) is recognised for its role in drought tolerance by promoting stomatal closure to reduce water loss. This study identifies that drought treatment upregulated the C2H2-type zinc finger protein SlZAT5 and the bHLH transcription factor SlJIG, leading to enhanced ABA accumulation and drought tolerance. Immunoprecipitation-Mass Spectrometry (IP-MS) analysis revealed the interaction between SlZAT5 and SlJIG. Both transcription factors can bind to the promoter of the ABA catabolism gene SlCYP707A3. However, SlJIG alone was insufficient for transcriptional repression of SlCYP707A3, which instead required SlZAT5's transrepression activity. Additionally, SlJIG strengthened the inhibitory effect of SlZAT5 on SlCYP707A3. Overexpression of either SlZAT5 or SlJIG improved tomato drought tolerance, whereas knockout of either gene reduced drought tolerance, with the double mutant exhibiting a further decline. These findings elucidate the role of the SlZAT5-SlJIG module in regulating tomato drought responses via ABA homoeostasis.

Caffeine biosynthesis in tea plants (Camellia sinensis) is dynamically regulated by environmental cues; however, the mechanisms linking early drought signals to caffeine accumulation remain unclear. Here, we show that acute PEG-induced osmotic stress induces rapid caffeine accumulation, accompanied by transcriptional activation of the key biosynthetic gene CsTCS1. Through integrative analyses, including GWAS and co-expression network modeling, we identified a CsBPC6-CsNACX2-CsTCS1 module as a central regulatory hub. Mechanistically, CsNACX2 directly binds the promoter of the caffeine synthase gene CsTCS1, activating its transcription and promoting caffeine accumulation. Moreover, the drought-responsive transcription factor CsBPC6 acts upstream to transactivate CsNACX2. Functional validation using gene silencing and transient overexpression assays confirmed that the CsBPC6-CsNACX2-CsTCS1 module positively regulates caffeine biosynthesis under PEG-induced drought conditions. Collectively, our findings uncover a previously uncharacterized drought-responsive transcriptional module governing caffeine biosynthesis, providing new mechanistic insights into how environmental cues regulate secondary metabolism in tea plants.

The timing of autumn leaf senescence is driven by external cues such as temperature and photoperiod and is strongly regulated by internal developmental processes. Correlative evidence suggests that earlier budburst and warmer conditions in spring and summer could accelerate development and advance senescence, yet this hypothesis remains largely untested experimentally. We investigated how early-season warming affects growth and senescence timing in three European tree species (Carpinus betulus, Tilia cordata and Acer platanoides). Saplings were grown under ambient or warmed open-top chambers (+5°C) from January to the summer solstice, after which all saplings were maintained under identical conditions. Warming advanced leaf-out by 14-28 days in all species. While height growth was unaffected by warming, radial growth increased significantly in T. cordata and C. betulus. Early signs of senescence (20% leaf discolouration or leaf fall) occurred significantly earlier in saplings exposed to pre-solstice warming in C. betulus (-31 days) and T. cordata (-24 days), with effects weakening but remaining significant at later senescence stages. In contrast, A. platanoides showed no warming-induced changes in growth and senescence timing. Our results suggest that early-season warming can advance autumn senescence, and this response may be associated with species-specific differences in early-season growth dynamics. These findings are consistent with a potential role of growth and carbon dynamics in linking spring conditions to autumn phenology, although the underlying mechanisms remain to be directly tested. Incorporating such developmental processes into vegetation models may improve predictions of growing season changes under climate warming.

Plant-fungus-virus tripartite interactions represent complex ecological systems in which mutualistic endophytes can influence host physiology, yet the molecular basis of endophyte-mediated defence remains poorly understood. Here, we demonstrate that the endophytic fungus Penicillium pinophilum EU0013 suppresses the yellow strain of cucumber mosaic virus (CMV-Y) in Solanum lycopersicum and Nicotiana benthamiana. CMV-Y infection induced pronounced oxidative and hormonal perturbations, which were mitigated by P. pinophilum colonisation. Endophyte-associated plants exhibited early accumulation of jasmonate intermediates, consistent with the activation of jasmonate signalling. This response promoted the degradation of jasmonate-ZIM-domain proteins and release of core JA-responsive transcription factors. Virus-induced gene silencing identified MYC2 as a key regulator required for endophyte-mediated antiviral protection, with WRKY17 contributing to defence modulation. In parallel, transcriptome analysis revealed the upregulation of a Dicer-like gene, indicating enhanced engagement of RNA silencing, a primary antiviral mechanism targeting viral RNA. This coordinated activation occurred alongside significant induction of pathogenesis-related proteins, particularly PR9, and improved control of reactive oxygen species. Salicylic acid-responsive defences showed a host-modulated pattern, with PR1 induced by CMV and PR2/PR5 preferentially enhanced in endophyte-associated plants. Collectively, these findings demonstrate that P. pinophilum enhances antiviral immunity through coordinated defence integration pathways, providing a framework for endophyte-based viral disease management.

Rising atmospheric CO₂ has significant implications for crop productivity and food security. Based on studies in C3 plants, elevated CO₂ (eCO₂) can shape plant-pathogen interactions, although the outcomes are often variable. The question of how eCO₂ influences immunity and disease development in C4 plants, such as the globally important cereal crop maize (Zea mays L.), has not been systematically examined. We challenged maize plants grown under ambient CO₂ (aCO₂, 420 ppm) and eCO₂ (550 ppm) with bacterial, viral, fungal, and oomycete pathogens. Plants grown in eCO₂ were more susceptible to sugarcane mosaic virus, suggesting compromised antiviral defenses, less susceptible to Clavibacter nebraskensis, Exserohilum turcicum, and Colletotrichum graminicola, and susceptibility to Puccinia sorghi and Pythium sylvaticum was unchanged. Reduced susceptibility to C. nebraskensis was associated with enhanced basal immune responses. These results establish a foundation for dissecting eCO₂-responsive defense mechanisms, and they highlight a critical need to understand how eCO₂ will impact plant responses to microbes, pests, and abiotic stresses under future conditions.

Phosphorus is essential for plant growth and reproduction. Plants have evolved diverse strategies to adapt to fluctuations in inorganic phosphate (Pi) availability by reprogramming gene expression. In addition to transcriptional regulation, RNA decay plays a crucial role in mRNA metabolism. In this study, we investigated whether RNA decay influences mRNA stability and whether m⁶A and m⁵C modifications and poly(A) tails are involved in this process, using Direct RNA sequencing for detection. We successfully established a genome-wide mRNA decay assay in rice and found that mRNA decay rates are primarily determined by G/C content in the 5' UTR, G/C content and RNA secondary structures in the CDS, m⁶A and m⁵C modifications in the 3' UTR, as well as the number of introns and the length of poly(A) tails. Both phosphate-starvation-induced (PSI) and phosphate-starvation-downregulated (PSD) genes decay faster than non-responsive genes, likely due to their higher CDS G/C content, fewer introns, and lower m⁶A modification rates. Pi starvation accelerated the decay of PSI genes but slowed the decay of PSD genes. Nanopore Direct RNA sequencing revealed that m⁶A modification and poly(A) tail length, rather than m⁵C modification, play central roles in regulating mRNA decay under Pi starvation. Furthermore, overexpression of the m⁶A reader OsYTH10 protected m⁶A-modified transcripts of OsPT2 and OsPAP21b from degradation, thereby enhancing Pi accumulation in rice. Collectively, our findings demonstrate that phosphate starvation remodels m⁶A methylations and poly(A) tails to modulate mRNA stability and shape the gene expression landscape in rice.