Plant Science最新文献

Cultivation of high-value medicinal plants on contaminated land requires reliable biomarkers and sustainable remediation strategies. We evaluated a multispecies arbuscular mycorrhizal fungi (AMF) consortium (Rhizophagus irregularis, Funneliformis mosseae, Claroideoglomus etunicatum) for enhancing stress resilience and phytochemical quality of Psoralea corylifolia under hexavalent chromium [Cr(VI)] exposure (0, 25, and 50mgkg⁻¹). Cr(VI) stress increased oxidative burden, membrane injury, and Cr accumulation, while impairing PSII efficiency, nutrient acquisition, biomass production, and seed yield. AMF inoculation substantially alleviated these effects by improving the uptake of essential nutrients (N, P, Mg, Fe, and Zn), strengthening antioxidant protection, and preserving membrane stability, resulting in improved growth and reproductive output under chromium stress. Notably, AMF-colonized plants produced seeds with increased accumulation of key bioactive metabolites, including bakuchiol, psoralen, and isopsoralen, even at the highest Cr(VI) level. Multivariate analyses identified mycorrhizal colonization as a robust integrative indicator linking nutrient status, redox homeostasis, and metabolite enrichment across treatments. Overall, AMF consortia represent an effective, biologically grounded approach to enhance chromium tolerance, stabilize yield, and improve the medicinal value of P. corylifolia. These findings support AMF-assisted cultivation as a practical strategy for producing high-quality medicinal raw material in chromium-contaminated soils while reducing the physiological and biochemical constraints imposed by metal toxicity.

Herbivory by insects poses a significant threat to plant survival and ecological stability. Kunitz-type protease inhibitors (KTIs) represent an important class of plant defense genes involved in responses to insect stress. In this study, we identified 33 KTI genes in the poplar genome, which are unevenly distributed across seven chromosomes. Phylogenetic analysis classified the encoded proteins into three subgroups, with members of the same subgroup sharing highly conserved motif composition and organization, suggesting functional conservation. RNA-seq analysis showed that feeding by Hyphantria cunea larvae significantly upregulated the expression of 15 PsnKTI genes in Populus simonii× P. nigra, with induction levels ranging from 2 to 234 times higher than those in undamaged plants. The most responsive gene, PsnKTI21, was selected for further functional characterization. Overexpression of PsnKTI21 in transgenic poplar reduced leaf damage upon insect feeding  by over 40%   and exerted a repellent effect on H. cunea larvae. Moreover, PsnKTI21 suppressed the expression of genes involved in trypsin production, detoxification, and trehalose metabolism in larvae, which led to a 78% reduction in larvae weight and a 73% increase in mortality, ultimately enhancing poplar pest resistance. Our findings elucidate the evolutionary conservation of the KTI gene family in poplar and highlight the key role of PsnKTI21 in insect defense, providing a valuable genetic resource for breeding pest-resistant poplar varieties.

Sugarcane is a global cash and bioenergy crop whose highly water-intensive cultivation poses a risk for sustainable production, especially given the progressively worsening drought stress scenario. This necessitates the development and use of high-yielding sugarcane varieties with improved water use efficiency and drought tolerance to meet current and future production goals. Given the crucial role of root system architecture (RSA) in lodging resistance, water uptake, nutrient absorption, and stress tolerance in sugarcane, understanding the genetic regulation of root development is essential for breeding high-yielding drought-tolerant varieties. Using gamma ray-induced in vitro mutagenesis of a popular sugarcane variety Co 99004, we have developed two sugarcane mutant lines- super shoot-root mutant (SRM) and rootless mutant (RLM). While SRM exhibited highly differentiating meristematic cells and accelerated root development, RLM was devoid of a proper root meristematic layer and root system. Using a tissue-specific transcriptome profiling, we have demonstrated that an auxin-centric transcriptional network of cell wall development-associated genes is responsible for the divergent root system architecture (RSA) exhibited by the mutant lines. Higher root growth in SRM was associated with the activation of coordinated network of auxin, histone, peroxidases and cell-wall remodelling hub genes. By contrast, HY5-mediated upregulation of light and photosynthesis-related gene expression contributed towards poor root development in RLM. The key hub genes identified by WGCNA are promising candidates for genetic improvement of RSA and drought tolerance in sugarcane. Finally, SRM, with its accelerated root development and vigorous RSA, holds potential agronomic relevance in present and future climatic scenario.

Wetland plants Acorus calamus (L.) face increasing drought pressure due to declining global rainfall. As a key wetland species contributing to ecosystem services such as water filtration, shoreline stabilization, and wildlife habitat provision, understanding its drought responses is essential for predicting wetland vulnerability and informing conservation strategies. This study investigated the physiological, morphological, and biochemical responses of A. calamus to varying levels of drought stress. Multiple drought-responsive parameters were assessed, revealing significant changes in photosynthetic pigments, morphological traits, and stress indicators, including malondialdehyde and proline. With increasing drought severity, leaf gas-exchange parameters such as net photosynthesis, transpiration rate, stomatal conductance, water use efficiency, and intrinsic water use efficiency declined significantly (p < 0.001). Functional traits, including leaf area, leaf area index, leaf area ratio, and specific leaf weight ratio, also showed significant reductions (p < 0.001). In contrast, root length, total phenolic content, soluble sugars, starch, proline, and malondialdehyde increased progressively with drought stress. These findings revealed that A. calamus undergoes pronounced physiological and biochemical limitations under drought conditions, highlighting the sensitivity of wetland plants to water shortage and underscoring the vulnerability of wetland ecosystems under ongoing climatic change.

Over the past three decades, efforts to decipher plant metabolism have shed light on key enzymes driving specialized metabolite biosynthesis. Although only few pathways have been completely investigated to date, their characterization paves the way for exploring the potential effects of specialized metabolites on plant physiology. Among them is the linear furanocoumarin pathway, which was recently completed to produce up to psoralen. In this study, we report the first metabolic engineering of the linear furanocoumarin pathway to enable artificial psoralen production in tomato, through the integration of four genes coding for the enzymes: Umbelliferone Synthase (PsDiox), Demethylsuberosin Synthase (PsPT1), Marmesin Synthase (FcCYP76F112) and Psoralen Synthase (PsCYP71AJ3). Metabolic analyses confirmed the detection of small quantities of psoralen in the transgenic tomato line, but also highlighted a larger accumulation of coumarins and particularly scopoletin. Using morphophysiological and multi-omics analyses, we explorate how such metabolic modifications, could impact growth and affect plant physiology.

Rosa persica is known for its purple-red basal spots and is considered the primary genetic source of spotted cultivars within the Rosa genus. The formation of these red spots is primarily attributed to the specific accumulation of anthocyanins. However, the regulatory mechanisms underlying this pigmentation remain poorly characterized. To investigate this process, we first combined microscopic and metabolomic analyses, revealing that three cyanidin derivatives (Cy3G5G, Cy3G, and Cy3R) accumulate exclusively in the upper epidermis of the spot region. Subsequently, we identified an R2R3-MYB transcription factor, RpMYB113, as a key regulator. Functional validation showed that transient overexpression of RpMYB113 in R. chinensis 'Old Blush' induced intense anthocyanin production, a result corroborated in stably transformed Nicotiana tabacum. Simultaneously, Y1H assays confirmed that RpMYB113 directly binds to the RpDFR promoter, identifying RpDFR as a direct target. Importantly, population genetic analysis established that RpMYB113 and its associated Hap4 haplotype were defined as a core genetic unit that has undergone repeated selection during evolution and can achieve the same complex phenotype across genetic backgrounds. Thus, through a multi-tiered approach spanning cellular, metabolic, molecular, and population-level evidence, this study elucidates the mechanistic basis of anthocyanin patterning in R. persica petal spots. KEY MESSAGE: We revealed a critical role of RpMYB113 in regulating anthocyanin accumulation within the petal spot zones of Rosa persica, providing a potential target for molecular breeding of spotted cultivars in Rosa species.

BLISTER (BLI) is a plant-specific protein with multifaceted functional roles, and its function in the context of Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) pathogenesis is unknown. Here we demonstrate that BLI functions as a negative regulator of immune responses against Pst DC3000 in Arabidopsis thaliana. Genetic analysis revealed that bli-1 loss-of-function mutant exhibited significantly enhanced disease resistance, whereas BLI-overexpressing lines showed compromised resistance compared to wild-type plants. Notably, Pst DC3000 infection induced substantial accumulation of BLI protein. Mechanistic investigations uncovered a reciprocal regulatory relationship between BLI and salicylic acid (SA). SA treatment significantly up-regulated BLI mRNA expression, while BLI overexpression attenuated SA-mediated defense responses. Further molecular dissection revealed that BLI modulates SA homeostasis by enhancing the transcriptional activity of NAC transcription factors ANAC019, ANAC055 and ANAC072. This regulatory effect appears to be mediated through physical interaction with the abscisic acid-responsive element binding factor ABF4. Collectively, our findings establish BLI as a critical negative regulator of Pst DC3000 resistance that operates through SA signaling pathways, providing new insights into the complex regulatory networks governing plant-pathogen interactions.

Transgenic apple cultivars may pose environmental safety concerns, particularly regarding pollen dispersion. Grafting non-transgenic scions onto transgenic rootstocks offers a promising strategy to combine desirable trait regulation with minimized risk of transgene flow via pollen. In China, Malus robusta Rehd. is one of the most widely used apple rootstocks. However, their transformation efficiency and reproducibility remain limited. In this study, we identified a high-regeneration genotype BL-57 from seedlings of Malus robusta Rehd., optimized the leaf regeneration and Agrobacterium-mediated genetic transformation system, and finally established a stable transgenic system for both gene knockout and overexpression. Leaf explants were initially cultured on Murashige and Skoog (MS) medium supplemented with 0.3 mg/L 6-benzylaminopurine (6-BA), 0.2 mg/L indole-3-acetic acid (IAA), 0.1 mg/L gibberellic acid 3 (GA₃), 30 g/L sucrose, and 7.5 g/L agar. Following leaf transection, the explants were transferred to MS medium containing 2 mg/L thidiazuron (TDZ), 0.5 mg/L naphthaleneacetic acid (NAA), 30 g/L sucrose, and 7.5 g/L agar, where the highest regeneration efficiency was observed, with an average of 15 shoots per explant. Leaf explants infected with Agrobacterium were cultured on bud induction medium supplemented with 6 mg/L kanamycin and 250 mg/L cefotaxime. The regenerated plantlets were identified and verified, demonstrating that the transgenic systems for gene knockout and overexpression have been successfully established in BL-57. In summary, we identified a M. robusta germplasm with high regeneration ability, and established an efficient leaf regeneration and transformation system. This platform provides a valuable tool for advancing molecular breeding and functional genomics research in apple.

In grapevine (Vitis vinifera), vacuolar accumulation of flavonoids such as anthocyanins and tannins is crucial for the organoleptic properties of wine, including color, aroma, and astringency. This process depends on proton pumps that generate an electrochemical gradient, enabling the active transport of flavonoids into the vacuole. In this study, we functionally characterize VviAHA10, a putative P3A-type H⁺-ATPase highly expressed in grape berry skins during veraison and post-veraison stages. Phylogenetic, structural, and motif analyses support its classification as a conserved vacuolar proton pump. Heterologous expression assays in tobacco showed that VviAHA10 is sufficient to promote vacuolar flavonoid accumulation, while in Arabidopsis thaliana, VviAHA10 rescued the anthocyanin and proanthocyanidin accumulation defects of the tt13-6 mutant. VviAHA10 expression also restored vacuolar pH homeostasis and root growth under complete phosphate starvation, salt stress, and combined stress conditions, enabling stress-induced anthocyanin accumulation comparable to wild-type levels. Confocal imaging of vacuolar pH in roots further revealed that VviAHA10 enhances vacuolar acidification capacity during stress. Altogether, our findings show VviAHA10 has the capacity to regulate flavonoid accumulation and stress-associated cellular processes when expressed in heterologous plant systems. These results highlight VviAHA10 as a promising molecular target for improving grape berry quality and resilience under changing environmental conditions.