Plant Cell Reports最新文献

Key message: The overexpression of VlPAT2 enhances the resistance of grapevine and Arabidopsis thaliana to Botrytis cinerea, and promotes the accumulation of reactive oxygen species, as well as the expression of multiple PR genes and R genes. Grape grey mould caused by the necrotrophic fungus Botrytis cinerea causes severe economic losses to the grape industry. Identifying disease resistance genes and elucidating their mechanisms provide critical insights for molecular breeding. Here, we report a GRAS family transcription factor VlPAT2 from the grapevine cultivar 'Beta' (Vitis labrusca) that exhibits high resistance to B. cinerea, which is involved in positively regulating grape resistance to this fungal pathogen. The VlPAT2 expression is responsive to treatments of salicylic acid, ethephon, bacterial flagellin peptide flg22, and hydrogen peroxide (H₂O₂). Overexpression of VlPAT2 in grapes and Arabidopsis thaliana can enhance resistance to B. cinerea, accompanied by the accumulation of reactive oxygen species (ROS). In addition, the transcriptional levels of salicylic acid signalling-associated defence genes (PR1 and PR5) and multiple resistance genes (R genes) were significantly upregulated in VlPAT2-overexpressing grape leaves. In conclusion, our findings indicate that the transcription factor VlPAT2 enhances disease resistance in grapevines and provides a gene source for the molecular breeding of grape varieties resistant to B. cinerea.

Key message: RNAi mediated combinatorial silencing of StUGPase and StVInv genes in potato demonstrated significant reduction of sucrose and reducing sugar accumulation after cold storage with improved chipping quality. Potato (Solanum tuberosum L.) is stored in cold conditions after harvest to maintain year-round availability by preserving its physiological vigour and preventing rotting. However, cold storage of potato leads to cold-induced sweetening, an undesirable physiological pathway of breakdown of starch into reducing sugars (RS), primarily glucose and fructose. These RS react with free amino acids at high temperature, producing dark, bitter-tasting products due to non-enzymatic Maillard reaction, rendering the tubers unsuitable for processing. UDP-glucose pyrophosphorylase (StUGPase) and vacuolar acid invertase (StVInv) are the two key enzymes that play central roles in the CIS pathway. To mitigate CIS, a combinatorial RNA interference (RNAi) approach was adopted to simultaneously silence both genes. A hairpin RNA (hpRNA) construct, CISCOM, was designed by fusing cDNA fragments of StUGPase and StVInv in sense and antisense orientations, separated by the potato GBSS intron. CISCOM transgenics of two Indian cultivars of processing quality, Kufri Chipsona-1 (KC1) and Kufri Chipsona-3 (KC3), demonstrated significantly low sucrose and RS accumulation following one month of cold storage at 4 °C due to many folds reduction at the transcript level and activities of both the enzymes. Chips produced from cold-stored RNAi potato tubers were lighter in colour, as acceptable by processing standards, compared to those from non-transgenic controls, which were unacceptably dark brown in colour. The study highlights the potential of combinatorial RNAi as an effective strategy to ameliorate cold-induced sweetening and much needed boost to the potato processing sector.

Key message: We resolved that SlMYC2 positively regulated tomato leaf senescence by inhibiting ROS scavenging capacity and exacerbating oxidative damage and PSII functional decline using a darkness-induced senescence model. Tomato leaf senescence seriously affects its yield and quality. Jasmonic acid (JA) signaling can promote tomato leaf senescence, but the mechanism is unclear. SlMYC2, as a core transcription factor in JA signaling, may play a role in regulating leaf senescence. Therefore, this study used SlMYC2 overexpression and silencing lines to systematically analyze the mechanism of SlMYC2 regulation of leaf senescence through a darkness-induced senescence model. The results showed SlMYC2 accelerated the leaf senescence process in tomato by increased chlorophyll degradation and malondialdehyde accumulation in SlMYC2-OE lines after dark treatment, and the expressions of senescence-related genes SlSGR1, SlSAG12, and SlSAG15 were significantly upregulated. At the photosynthetic physiological level, SlMYC2-OE caused damage to photosystem II (PSII) function, with a significant decrease in maximum photochemical efficiency (F_v/F_m) and performance index (PI_ABS), and exacerbated damage to the donor side (W_k). Further studies found SlMYC2 accelerated programmed cell death (PCD) by promoting the accumulation of reactive oxygen species (ROS). The contents of superoxide anion (O₂^⁻·) and hydrogen peroxide (H₂O₂) significantly increased in the SlMYC2-OE lines, while the contents of ascorbic acid (AsA) and glutathione (GSH), as well as the activities and gene expressions of key antioxidant enzymes such as SOD, POD, CAT, APX, and GR were all inhibited. In summary, SlMYC2 has been shown to inhibit the removal of reactive oxygen species (ROS), exacerbate oxidative damage and photosystem II (PSII) function decline, and positively regulate the process of leaf senescence in tomato. This study will provide a theoretical foundation for targeting the JA signaling pathway to regulate tomato senescence.

Key message: The present study demonstrates the first CRISPR/Cas-mediated precise knock-in of the eGFP gene at the BABYBOOM2 (GN-BBM2) locus in banana cv. Grand Naine, facilitating the detection of editing events in early embryogenic developmental stages. Genome editing has accelerated crop improvement programs by introducing targeted and precise genetic modifications. Among different tools, CRISPR/Cas-based genome editing has been widely used for enabling mutations through double-stranded breaks (DSBs), repaired either by non-homologous end joining (NHEJ) for gene knockouts or homology-directed repair (HDR) to generate knock-in events. While gene knockouts are well established in banana, efficient knock-in remains a major challenge due to low HDR activity, sterility, and the vegetatively propagated nature of banana. In the present study, we report the first successful CRISPR/Cas-based gene knock-in editing in banana by targeting the BABYBOOM2 (BBM2) gene, which encodes a transcription factor involved in somatic embryogenesis. The enhanced green fluorescent protein (eGFP) gene was precisely inserted at the BBM2 locus in banana cv. Grand Naine to enable visual detection during embryogenesis. In vitro validation showed ~ 95% target cleavage efficiency of the selected gRNA. The PCR-based screening and shift-in amplicon size analyses confirmed three edited lines (#3, #11, and #14) harboring eGFP knock-in at the targeted locus. Sequencing of the amplicon from these lines further confirmed the precise knock-in events. Hence, this study establishes a foundation for precise knock-in-based genome modification in banana and opens new avenues for targeted trait improvement in this important clonally propagated crop.

Key message: This study uncovers a temperature-mediated, localized auxin status perturbation in the meristem region responsible for root growth suppression under elevated temperature environments, revealing novel insights into root-environment interactions. Agriculture is highly sensitive to weather and climate because of its heavy reliance on temperature, water, and other natural resources. Among these variables, plants are particularly susceptible to changes in ambient temperature due to its influence on growth and development throughout the life cycle. Therefore, global warming presents a fundamental threat to plant life and productivity. As this climate crisis worsens, it is critical to deepen our understanding about the adverse impacts of elevated temperature on aspects of plant development. In this study, we investigate the negative influence of a rising temperature environment on root system attributes. Compared to the shoot system, roots are known for higher thermosensitivity. Here, our findings demonstrate that besides growth, multiple root system aspects, such as gravitropism response, root system architecture, etc., are affected by elevated temperature environments. Root meristem activities appear to be highly auxin-dependent in a rising temperature environment compared to ambient growth conditions. Furthermore, our findings demonstrate a disruption in auxin status within the root meristem region, in plants exposed to elevated temperature. This temperature-mediated, localized perturbation in the auxin pathway contributes to defective cell proliferation activities and culminates in root growth suppression under elevated temperature. Collectively, these findings provide novel insights into the interplay between root system traits and a rising temperature environment.

Key message: SNFE framework identifies 10 key CTgenes and reveals novel cold-tolerance mechanisms in soybean. Cold stress poses a significant threat to soybean (Glycine max (L.) Merr) productivity, during early developmental stages. Traditional approaches for identifying cold-responsive genes have been limited by size bias, pathway redundancy, and lack of integrative validation. To address these challenges, we developed a multi-layered systems biology framework, termed SNFE (systems and network-based feature engineering), to uncover key cold-tolerant genes (CTgenes) by leveraging both panomics and non-omics data in a network-informed context. The SNFE framework integrates five analytical layers: functional pathway enrichment, pathway crosstalk, co-functional network construction, network topology analysis, and experimental validation. From an initial pool of cold-responsive genes, SNFE identified 10 key CTgenes demonstrating high connectivity, regulatory importance, and consistent differential expression in short- and mid-term cold conditions. These genes were validated via independent transcriptomic datasets, Quantitative real-time PCR analysis, and hormone profiling. Notably, SNFE revealed novel regulatory mechanisms, including dual-timed transcription factors, ABA-JA hormone synergy in membrane stabilization, and convergence of abiotic and biotic stress signaling. A Sankey diagram and volcano plot further confirmed that most CTgenes reside at key regulatory nodes, linking upstream functions to downstream cold-tolerance pathways. SNFE is a reliable, efficient, and interpretable tool that not only improves prediction accuracy but also enables the discovery of novel biological insights. Its scalability and analytical depth make it a powerful platform for dissecting complex stress responses in crops. This framework provides a strategic foundation for molecular breeding; we also discuss the potential of multiplex "full gene packages" as a downstream engineering avenue to enhance cold resilience.

Key message: This study first demonstrates that PsGSH2 enhances cadmium tolerance not only by boosting antioxidant defense but also by modulating metal transporter genes to reduce Cd accumulation in plants. Cadmium (Cd) stress poses a significant environmental issue. Potentilla sericea, characterized by strong resistance, is an excellent groundcover for pollution remediation. Glutathione synthetase is one of the key enzymes that promote the synthesis of the antioxidant glutathione (GSH). We cloned PsGSH2, which was up-regulated under Cd stress, and introduced it into Arabidopsis thaliana to validate the response of transgenic lines to Cd. The results showed that the expression level of PsGSH2 was significantly up-regulated (15.45-fold) in the roots of P. sericea under cadmium stress. Overexpression (OE) of PsGSH2 in A. thaliana significantly enhanced Cd tolerance. Compared to wild-type (WT) plants, OE lines exhibited a more than sevenfold increase in seed germination rate under Cd stress, with a significantly reduced biomass loss (< 40%). The transgenic lines showed enhanced photosynthetic performance, a reinforced antioxidant system (up to 1.9- and 2.2-fold higher than WT), and reduced oxidative damage (50-75% of WT). Crucially, they exhibited a 59.05% reduction in shoot Cd accumulation, supported by significantly lower bioconcentration factor and transport factor values (46.12% and 69.17%, respectively). Molecular analysis revealed upregulation (1.84- to 5.44-fold) of key genes related to Cd detoxification (AtGSH1, AtGSH2, AtIRT1, AtPCR1, AtPCR2, AtMT3). Therefore, this study provides valuable insights for developing Cd-tolerant plants through genetic engineering approaches, laying the foundation for further research on Cd resistance in P. sericea.

Key message: We identify 30 plant genera supporting GFP expression via syringe agroinfiltration, demonstrating a versatile system for non-model plant research.

Drought is a major abiotic constraint that limits plant growth and productivity worldwide. To cope with water scarcity, plants employ complex adaptive strategies, with stomatal regulation serving as a central mechanism for balancing water conservation and photosynthetic efficiency. Phytohormones are crucial signaling mediators in this process, coordinating the molecular, physiological, and biochemical responses that govern stomatal dynamics during drought. Abscisic acid (ABA) is the principal regulator of drought-induced stomatal closure; however, other hormones, including salicylic acid, methyl jasmonates, ethylene, gibberellins, cytokinins, and auxins, modulate stomatal function through synergistic or antagonistic interactions. Such hormonal crosstalk shapes guard cell sensitivity to ABA, regulates ion channel activity, influences transcriptional networks, and ultimately determines water-use efficiency. While earlier reviews have addressed the broader roles of phytohormones in drought adaptation, they often overlook the nuanced regulation of stomatal behavior. This review uniquely synthesizes recent advances in phytohormone signaling networks, with particular emphasis on their synergistic and antagonistic crosstalk and downstream signaling cascades that govern stomatal regulation under drought stress. It further integrates current insights into hormone-mediated adaptive responses coordinated with stomatal dynamics, establishing a mechanistic framework that links molecular signaling with physiological regulation and drought tolerance. We also highlight emerging strategies to harness hormonal regulation to enhance drought resilience and outline key research priorities for translating these insights into crop improvement.