Plant Cell Reports最新文献

Key message: AtNPR1 expression strengthens Fusarium wilt resistance in chickpea by activating SAR. Multi-omics analyses suggest CaDEAD-box20 as a candidate gene contributing to resistance through possible interaction with AtNPR1. Traditional breeding for broad-spectrum disease resistance in crops is often slow and resource-intensive, whereas genetic engineering provides a more precise and efficient alternative. To enhance resistance in chickpea (Cicer arietinum) against Fusarium oxysporum f. sp. ciceris, the causal agent of Fusarium wilt, we introduced the Arabidopsis NPR1 (AtNPR1) gene to activate systemic acquired resistance (SAR). We found that transgenic chickpea plants expressing AtNPR1 exhibited markedly reduced reactive oxygen species (ROS) accumulation, higher expression of defense-related genes, and up to 41% greater resistance compared with wild-type (WT) plants. qRT-PCR analysis revealed a higher fungal DNA load and increased expression of virulence genes in infected WT plants relative to transgenic lines. We also observed elevated salicylic acid (SA) levels and strong induction of pathogenesis-related (PR) genes in transgenics at 2 days post-infection (dpi). Although jasmonic acid (JA) content did not differ significantly between genotypes, methyl jasmonate (MeJA) treatment confirmed activation of JA pathway genes in both. To elucidate the molecular basis of resistance, label-free quantitative proteomics (LC-MS/MS) and metabolomics (GC-MS) analyses were performed, revealing 205 differentially expressed proteins and 38 metabolites associated with defense responses. Protein-protein interaction assays (BiFC and modeling) suggested an interaction between AtNPR1 and chickpea DEAD-box RNA helicase 20 (CaDEAD-box20). Functional validation showed that CaDEAD-box20 positively regulates resistance, as its overexpression enhanced, whereas its knockout reduced, tolerance to Fusarium wilt. Overall, we demonstrate that AtNPR1 enhances Fusarium wilt resistance in chickpea by coordinating SA- and JA-mediated defense pathways, with CaDEAD-box20 serving as a key regulatory component.

Key message: Tomato m⁶A writers and erasers were identified genome-wide. Furthermore, their inhibition was found to affect seedling growth, and these genes respond to various stimuli, including PEG, MeJA, ABA, GA₃, and SA. The balance between methylation and demethylation in N⁶-methyladenosine (m⁶A) determines the level of m⁶A modification in multiple species. The m⁶A modification is associated with abiotic stress and plant hormone responses. Therefore, it is crucial to investigate the bioinformatics and expression patterns of writer and eraser genes under these conditions. Here, we report the function of 7 writer genes (SlMTA, SlMTB1, SlMTB2, SlMTC, SlVIR, SlFIP37, SlHAKAI) and 8 eraser genes (SlALKBH1, SlALKBH2, SlALKBH6, SlALKBH7, SlALKBH8, SlALKBH9A, SlALKBH9B, SlALKBH9C). Phylogenetic analysis reveals the evolutionary relationships among the genes of the writers and erasers, providing the conservativeness of evolution. Analysis of cis-regulatory elements suggest that writers and erasers may be involved in stress or plant hormone process. Furthermore, pharmacological experiments using 3-deazaneplanocin A (3-DA) or meclofenamic acid (MA) have demonstrated that inhibition of m⁶A methylation or demethylation, suppresses the growth of tomato seedlings and regulates the expression of the writer and eraser genes. These findings suggesting that m⁶A methylation dynamics are involved in the plant's response to drought stress and plant hormone. Moreover, quantitative reverse transcription further confirmed the effects of polyethylene glycol (PEG), abscisic acid (ABA), methyl jasmonate (MeJA), gibberellic acid (GA3), and salicylic acid (SA) on the expression of writer and eraser genes. These results indicate that m⁶A modification plays an important role in the growth of tomato seedlings and is also associated with the plant's response to drought stress and ABA, MeJA, GA3, and SA.

Starch branching enzymes (BEs) play crucial roles in determining amylopectin structure, starch components, and ultimately, starch properties and crop quality. This review begins by outlining starch biosynthesis and its relationship with starch properties and rice qualities. We summarized the current understanding of the tertiary structure, catalytic mechanism, and key functional sites of BEs, encompassing catalytic residues, substrate-binding sites, and phosphorylation sites. The regulating BEIIb for modulating amylopectin chain length distribution, starch crystalline lamellar structure, starch granule morphology, starch gelatinization resistance, and starch resistance to enzymatic hydrolysis is reviewed. The regulatory impacts of BEIIb deficiency (via frameshift mutation or expression downregulation) and amino acid substitution on rice qualities are critically discussed. Finally, we proposed some future research directions, including: high-throughput screening and identification methods for BEIIb allelic mutants exhibiting a transparency endosperm, utilizing base editing technology to create novel elite BEIIb alleles, pyramiding multiple genes to develop novel rice germplasm rich in resistant starch while maintaining elite grain quality, especially for appearance quality and eating and cooking quality, and integrating AI and machine learning to predict regulation effects. This review not only enriches the theoretical framework concerning BEIIb-mediated regulation of starch components and rice qualities but also provides some specific molecular targets within BEIIb for targeted quality improvement strategies.

Stilbenes, including resveratrol, piceatannol, and piceid, are valuable plant secondary metabolites but are often limited in terms of bioproduction yield. This study represents the first attempt to modulate stilbene production pathways in peanut (Arachis hypogaea) cells. We investigated the potential of L-phenylalanine, sodium malonate dibasic, and cerulenin as metabolic modulators to promote stilbene biosynthesis. These modulators were tested at different concentrations and time points in both peanut callus cultures and cell suspension cultures. The effects of these modulators on cell growth and stilbene production were assessed. The results revealed that metabolic modulators significantly influence the production patterns of resveratrol, piceid, and piceatannol in peanut cells. Interestingly, both static and suspension cultures displayed distinct responses, with metabolite type and yield depending on the growth phase, modulator concentration, and incubation time. Our findings showed that 0.0002 mM cerulenin was the most effective modulator, resulting in more than a tenfold increase in resveratrol production in callus cultures. In cell suspension cultures, 0.5 mM sodium malonate dibasic also enhanced the production of resveratrol during the lag phase, whereas piceatannol and piceid were more prominently produced during the stationary phase. This effect was more significant than that observed with phenylalanine and cerulenin. This research provided valuable insights into metabolic pathway regulation within peanut cells and established a novel host system as a viable platform for future stilbene production.

Key message: A total of 13 FtGAPDHs was identified in buckwheat and FtGAPDH7 plays a key role in heat stress response. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is an essential enzyme of the glycolytic pathway that helps in the production of energy in living cells. GAPDH is a multifunctional enzyme that performs several roles including participation in plant growth and development, enhancing resilience to biotic and abiotic stress, and safeguarding genome integrity. In the present study, a total of 13 GAPDH genes were identified across the eight chromosomes in buckwheat [Fagopyrum tataricum (Ft)], comprising eleven GAPDH genes and two GAPN genes. The cis-regulatory element analysis elucidated that the FtGAPDH genes may regulate diverse biological processes and exhibit responses against various biotic and abiotic stressors. FtGAPDH gene expression analysis was conducted in different abiotic stresses, including heat, cold, salt, and drought stress, to comprehend the functions of these genes in mediating abiotic stress responses. In cold stress, FtGAPDH8/10 and 11 showed significant upregulation by 13.6-fold, 4.8-fold, and 25.3-fold, respectively. Under drought stress, significant downregulation was observed in FtGAPDH6/8 and 9. Similarly, salt stress led to the downregulation of maximum genes, and FtGAPDH1/2/10 and 11 showed significant downregulation. Under heat stress, FtGAPDH2/3/6/7/9/10 and 11 exhibited significant upregulation, with the most pronounced increase observed in FtGAPDH7, which was upregulated up to 66-fold. Furthermore, the overexpression of FtGAPDH7 in buckwheat and in Nicotiana benthamiana resulted in higher chlorophyll content, Fv/Fm and reduced malondialdehyde (MDA) and electrolyte leakage levels under heat stress as compared to the wild type, indicating enhanced photosynthetic efficiency and reduced oxidative damage, which provides evidence that this gene might be involved in thermotolerance. This study highlights the potential roles of FtGAPDH7 genes in heat stress responses, providing a foundation for their functional validation to understand the regulatory mechanism and eventually to develop heat stress-tolerant buckwheat cultivars.

Key message: Coordinated transcriptional networks orchestrate fatty acid and triacylglycerol synthesis in olives, with ABA signaling and specific transcription factors regulating lipid pathways that define extra-virgin olive oil quality. Health benefits of olive oil are due to the unique fatty acid (FA) profile. However, the transcriptional mechanisms regulating FA biosynthesis during drupe ripening are poorly understood. Herein, we coupled transcriptomics, targeted FA profiling and weighted gene co-expression network analysis (WGCNA) to dissect lipid metabolism through four developmental stages of 'Koroneiki' drupes. FA quantification revealed a progressive decline in saturated fatty acids (SFAs) alongside a steady rise in monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs), notably oleic and linoleic acids. Transcriptome analysis identified 42 core genes of FA metabolism and triacylglycerol (TAG) biosynthesis. WGCNA revealed distinct transcriptional modules linked to progressive SFA reduction, late-stage MUFA accumulation and PUFA synthesis during drupe ripening. Expression of the saturation pathway genes progressively downregulated contrary to the desaturation pathway counterparts that determine the final oil composition leading to oleic acid prevalence. Intriguingly, ABA-biosynthesis and signaling genes were co-expressed with MUFA/PUFA modules, supporting a central role of ABA in late-stage lipid biosynthesis. Moreover, ABA-mediated regulation of lipid metabolism appeared to be fine-tuned by the contrasting expression of distinct PP2C homologs and coordinated by specific transcription factors. The expression dynamics of stearoyl-ACP desaturase SAD4 and the TAG assembly enzyme PDAT1 identify them as molecular markers of the transition from saturated to unsaturated fatty acids, leading to oleic acid enrichment during ABA-regulated olive drupe ripening. Overall, we present an integrated systems-level framework of the transcriptional networks driving olive oil biosynthesis, outlining a molecular toolbox to enhance extra virgin olive oil yield and quality.

Microplastic pollution has emerged as a critical environmental concern, particularly in agricultural soils, where various MP types, including polyethylene, polystyrene and polyvinyl chloride accumulate due to plastic mulch degradation, irrigation, and biosolid application. This review synthesizes current knowledge on the impacts of MPs on soil integrity and function, highlighting the degradation of soil structure, disruption of nutrient cycles and shifts in microbial community composition and enzymatic activity. Furthermore, MPs can be taken up by plants, with submicrometer sized particles infiltrating root tissues, triggering phytotoxic effects such as oxidative stress, impaired growth, and reduced photosynthesis. In response plants deploy tolerance mechanisms involving antioxidant defense and altered nutrient metabolism to mitigate MP-induced stress. Advanced omics technologies, including transcriptomics, metabolomics, and proteomics provide valuable insights into the molecular responses of plants to MP exposure, uncovering stress responsive genes, metabolite shifts and protein alterations linked to MP toxicity. This review synthesizes current knowledge on MP contamination in agricultural soil, its impact on soil health and plant physiology, and the application of multiomics approaches to elucidate MP-induced toxicity, paving the way for sustainable strategies to mitigate MP pollution in agroecosystems.

Key message: Using CRISPR/Cas12a, we engineered novel soybean germplasms by knocking out GmFAD2 (GmFAD2-1A, GmFAD2-1B) and GmFAD3 (GmFAD3A, GmFAD3B) genes, yielding elevated oleic or linoleic acid content. Soybean oil contains high levels of polyunsaturated fatty acids (PUFAs), which are known to reduce cholesterol levels and help prevent hypertension, thereby contributing significantly to human health. However, the chemical instability of PUFAs makes them susceptible to oxidation, a process that generates harmful trans-fatty acids. To address this issue, precise modulation of fatty acid composition in soybeans becomes critically important for health applications. In this study, we employed CRISPR/Cas12a gene editing technology to selectively knock out the GmFAD2 (GmFAD2-1A, GmFAD2-1B) and GmFAD3 (GmFAD3A, GmFAD3B) genes in soybean. This approach successfully created novel soybean germplasms with distinct fatty acid profiles: one with elevated oleic acid content and another with increased linoleic acid levels. These engineered variants provide valuable options for utilizing soybean oil with optimized fatty acid compositions tailored for specific health and nutritional purposes.

Key message: The RUBY reporter enabled the evaluation of different transgene expression constructs in lettuce, revealing that the lettuce ubiquitin promoter and terminator had strong expression that was stable over multiple generations. Nearly four decades after the first transgenic lettuce was reported, constructs for stable transgene expression remain limited. Notably, the 35S promoter from the Cauliflower Mosaic Virus (35S), which drives strong expression of transgenes in several plant species, has often shown silencing and instability in lettuce. Other promoter/terminator combinations that are commonly used in plant expression vectors have not been extensively studied in lettuce. In this study, we evaluated three different expression constructs in two different horticultural types of lettuce using the non-invasive RUBY reporter, which allowed for the monitoring of transgene expression throughout the process of regeneration during tissue culture, throughout development of the primary transgenics, and in two subsequent sexual generations. The LsUBI promoter/terminator combination resulted in strong, uniform expression throughout regeneration, during growth of the primary transgenics, and in both subsequent generations. The AtUBI promoter/tRBCS combination showed slightly lower levels of expression and intermediate levels of silencing, while the 35S promoter/tHSP combination showed both initial strong expression and frequent silencing. Therefore, our data show that the LsUBI promoter/terminator combination provides strong, uniform expression that is unlikely to result in silencing and that the AtUBI promoter/tRBCS combination is an additional option for stable expression of transgenes in lettuce, especially if an intermediate expression level is desired.

Key message: Novel endophytic bacterial consortium promotes the growth of Solanum lycopersicum surviving salt stress by differentially regulating the primary and secondary metabolic pathways. Crop yield is being impacted by global warming, which threatens food security. Salinization of soil or irrigation water is becoming increasingly prevalent in most agricultural terrain, especially around the coast. In India, it is estimated that approximately 10% of additional area is getting salinized, and around 50% of the arable land would be salt-affected by the year 2050. Finding innovative techniques that enable farmers to sustain production in an increasingly saline environment is crucial given the world's population expansion and the depletion of natural resources used in agriculture. Biostimulants are naturally occurring compounds or microorganisms that are used to promote plant functions, such as nutrient absorption, nutrient utilisation efficiency, abiotic stress tolerance, and the overall quality of the resulting agricultural products. In the present work, we evaluated the agronomic effectiveness of a novel formulated biostimulant consisting of four strains of endophytic bacteria isolated from the roots of mangrove plants of Sundarbans in a crop of great interest (Tomato) under controlled conditions and salt stress. Our research has shown that our product had a positive effect on the biochemical parameters in tomato plants under salt stress. The application of our biostimulant also increased osmolyte production and maintained Na⁺/K⁺ homeostasis under salt conditions. Similarly, when exposed to salinity, the biostimulant increased the concentration of signature molecules, including primary metabolites, phenolic compounds, polyamines, and phytohormones inside the plant cell. This study enriched our body of knowledge by providing novel perspectives on the mechanism of salt resistance that endophytic microbes provide through symbiosis.