Frontiers in Plant Science最新文献

Amid the growing global demand for sustainable crop production, plant factories with artificial lighting (PFALs) have gained attention as the systems provide stable, optimal growth environments for crops, and are largely unaffected by climate change. However, a limitation of widely used light-emitting diodes (LEDs) in PFALs is their decreased energy conversion efficiency at high output levels, prompting the search for more efficient light sources. This study focused on laser diodes (LDs), which has shown superior energy conversion efficiency, as an alternative. We developed an LD lighting system capable of mixing red and blue light at arbitrary ratios and mounted it onto a commercial gas-exchange measurement system. Using this system, photosynthetic parameters in rice were obtained under conditions of red light alone and as well as combined red and blue light illumination. Under red LD illumination alone, steady-state CO₂ assimilation rate, stomatal conductance, and transpiration rate in rice were significantly higher than those under red LED illumination, whereas intrinsic water-use efficiency decreased due to a relatively greater increase in stomatal conductance. Notably, stomatal conductance and transpiration rate exhibited pronounced temporal oscillations with a period of approximately 900 s, which closely corresponded to oscillations in stomatal aperture confirmed by microscopic observations. Under combined red and blue LD illumination, steady-state photosynthetic parameters did not differ significantly from those under LED illumination; however, the dominant oscillatory frequency observed under red LD alone was not detected, and some photosynthetic capacity parameters tended to decline. Furthermore, CO₂ response analyses revealed that, despite lower CO₂ assimilation, stomatal conductance responded more strongly to changes in intercellular CO₂ concentration under combined red and blue LD illumination. Taken together, these results demonstrate that LD lighting, particularly red LD, enhances stomatal dynamics and induces characteristic oscillatory behavior compared with LED lighting. While red LD appears to be a promising cultivation light source for PFALs capable of maintaining high photosynthetic activity, the physiological impacts associated with blue LD, including potential reductions in photosynthetic capacity, require further study to optimize blue-light proportions for rice cultivation.

Rapid and intelligent identification of rice pests serves as the core sensing technology for precision plant protection and smart rice farming systems, providing critical support for intelligent cultivation decisions. To address the challenges of insufficient robustness and low precision of existing lightweight detection models in complex agricultural environments, this study proposes HDA-YOLO, an improved lightweight YOLOv8 model based on a hierarchical and densely-fused attention mechanism, for fast and high-precision pest detection. To enhance feature fidelity, the model incorporates asymmetric dynamic downsampling (ADDS) and a multi-scale cascade pre-fusion (MCPF) module into the backbone network. To achieve dynamic, content-aware feature fusion, a hierarchical attention-driven dense fusion network (HADF-Net) is constructed, integrating an intra-scale self-attention module (ISAM) and an inter-scale cross-attention module (ICAM). Furthermore, the C2f module is upgraded to a multi-scale context (MSC) module to improve adaptability to variations in target scale. Experimental results on the self-built RicePest_12 dataset demonstrate that HDA-YOLO, while maintaining a lightweight architecture (3.93M parameters, 12.02 GFLOPs), achieves significant improvements over the baseline YOLOv8n model, with mAP@50, F1-score, and Recall increasing by 2.4%, 3.8%, and 4.8%, respectively. In comparison with the Transformer-based RT-DETR-R18 model, HDA-YOLO achieves a 4.8 percentage points higher mAP@50, while its computational cost is only 22% and its parameter count is only 20% of RT-DETR-R18. Moreover, the proposed model has been successfully deployed on a mobile application, achieving real-time and accurate identification of field pests and demonstrating significant potential in the field of smart rice agriculture.

Establishing an apple orchard involves a strategic combination of biological and structural decisions. Factors such as variety, rootstock, tree spacing, training system, and local environmental and economic conditions all interact to influence orchard performance over time. Understanding how these variables affect long-term profitability is essential for growers aiming to maximize returns on investment. This study presents an economic evaluation of a long-term field trial conducted in New York State (Yonder Farm, southeastern region) from 2007 to 2017. The trial focused on 'Delicious' apples and assessed the interaction between ten rootstocks (B.118, G.11, G.16, G.210, G.30, G.41, G.935, M.26, M.7, and M.9) and four training systems with varying planting densities: Super Spindle (5,382 trees·ha^-1), Tall Spindle (3,662 trees·ha^-1), Triple Axis Spindle (2,243 trees·ha^-1), and Vertical Axis (1,656 trees·ha^-1). Our results show that high-density systems, Super Spindle and Tall Spindle, consistently delivered the highest profitability, despite their higher initial establishment costs. These systems also achieved faster break-even points and greater cumulative net present value, especially with rootstocks such as G.11, G.210, and G.935. In contrast, lower-density systems like Vertical Axis and Triple Axis Spindle showed slower economic recovery and lower overall returns. The multi-leader Triple Axis Spindle system had lower profitability than higher density single stem systems (Tall Spindle and Super Spindle). This indicates that multi-leader trees planted at lower planting densities than Tall Spindle or Super Spindle with the goal to reduce initial establishment costs does not result in as high profitability as the higher density single stem systems. Profitability was not only influenced by training system but also by the compatibility between rootstock and planting density. Rootstocks such as G.41, G.11, and G.210 performed best under high-density conditions, while B.118 was more suited to low-density systems. Conversely, M.9 and M.7 showed limited economic potential, particularly when used in intensive planting systems. These findings underscore the importance of aligning rootstock vigor and precocity with the structural design of the orchard to optimize long-term economic outcomes.

Phosphorus is integral to energy transfer and structural integrity in plants, which plays a significant role in regulating secondary metabolism. Notably, low phosphorus (LP) stress significantly improves dendrobine content in Dendrobium officinale, yet the molecular basis for this induction remains unclear. This study employed transcriptomic analysis to identify the differentially expressed genes (DEGs) related to the dendrobine biosynthesis under LP stress in D. officinale. 1,713, 222, 488, and 174 DEGs were up-regulated among the different phosphorus treatment groups, including the HP (high phosphorus) vs TP (total phosphorus), MP (medium phosphorus) vs TP, LP (low phosphorus) vs TP and NP (no phosphorus) vs. TP, respectively. In contrast, 1,855, 195, 432, and 120 DEGs exhibited a down-regulated expression pattern between each of them, respectively. Gene annotation in public datasets revealed that the DEGs related to phosphate transporter and alkaloid biosynthesis were enriched in D. officinale. By co-expression analysis, 10 phosphorus transport-related transcription factors (TFs) and 21 TFs associated with dendrobine biosynthesis were mined from the D. officinale transcriptome. These above findings provide many candidate TFs related to dendrobines biosynthesis and new insights into dissecting the potential molecular mechanism on regulating dendrobine biosynthesis under LP stress in D. officinale.

Introduction: Soil salinization is a key limiting factor for global agricultural production and plant growth. However, the salt tolerance response mechanism of the medicinal plant Blumea balsamifera (L.) DC. has not been systematically investigated.

Methods: Fivemonthold seedlings of B. balsamifera were used as experimental materials, and five salt treatments were designed: control (CK), low salt (LS), moderate salt (MS), high salt (HS), and extremely high salt (EHS). Growth, photosynthetic, and physiological indices were measured. According to physiological changes, the HS and EHS groups at 12 d of treatment (when plants entered the core stress response stage) were selected for integrated multiomics analysis.

Results: With increasing salt stress, the net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) of B. balsamifera decreased continuously. The activities of superoxide dismutase (SOD) and catalase (CAT) increased first and then decreased, synergistically removing reactive oxygen species (ROS) with peroxidase (POD). Changes in osmotic adjustment substances and elevated lignin (LIG) content implied enhanced cell wall-related processes. Metabolomic analysis identified 677 and 692 differentially accumulated metabolites (DAMs) in HS vs CK and EHS vs CK, respectively, both enriched in flavone and flavonol biosynthesis. Transcriptomic analysis detected 30,213 and 13,644 differentially expressed genes (DEGs) in HS vs CK and EHS vs CK, respectively, both enriched in oxidative phosphorylation. Integrated analysis demonstrated that oxidative phosphorylation, flavone and flavonol biosynthesis, and cutin, suberine, and wax biosynthesis were the core response pathways, which mediated salt tolerance by regulating key DAMs (e.g., fumaric acid, kaempferol3Orutinoside, luteolin) and DEGs (e.g., flavonoid 3'monooxygenase, peroxygenaselike isoform X2).

Discussion: This study systematically clarifies the salt tolerance mechanism of B. balsamifera, providing a theoretical basis for its salttolerant breeding and the utilization of medicinal plant resources in salinized regions.

Introduction: Histone acetyltransferases (HATs) and histone deacetylases (HDACs) dynamically regulate histone acetylation and are involved in the process of plant growth and development and stress responses.

Methods: In this study, we identified 12 GmHATs and 28 GmHDACs in the soybean genome and systematically analyzed their phylogenetic relationships, structural features, expression profiles, and stress-induced acetylation dynamics using bioinformatics analysis, RT-qPCR, and western blotting.

Results: Cis-element analysis indicates that they may participate in hormone and stress signaling pathways, and transcriptome analysis revealed tissue-specific expression patterns. RT-qPCR results indicated that GmHATs and GmHDACs exhibited varying degrees of induced expression under salt and drought stress, particularly the GmHDA16 and GmHDT2. Notably, under salt stress, GmHDT2 expression increased 61-fold. Western blotting further demonstrated that salt and drought treatments significantly reduced H3K18ac and H4K8ac levels. Additionally, these genes exhibit distinct responses to various plant hormones.

Discussion: The reduction in acetylation was negatively correlated with the upregulation of HD2 subfamily genes, suggesting that specific HDACs mediate stress responses through histone deacetylation. This study provides new insights into the epigenetic regulation of abiotic stress in soybean, offering valuable genetic resources for future stress-resistant breeding programs.

This work aims at solving the problems of susceptibility of chrysanthemum seedlings with multiple fibrous roots to damage, poor adaptability of traditional clamping type transplanting machines, and unstable transplanting uprightness. According to the agronomic requirements of chrysanthemum transplanting and morphological characteristics of its seedlings, a spoon shaped clamping transplanting device of chrysanthemum seedlings was designed and optimized. A kinematic model was established based on its working principle, and a human-computer interaction analysis interface of the transplanting device was developed based on MATLAB, and the influence of key structural parameters on transplanting performance was analyzed through this interface, and the optimal parameter combination of the mechanism was determined. The transplanting trajectory was verified by simulation and field experiment. The results showed that the actual trajectory and simulation trajectory of spoon shaped clamping transplanting device were in good agreement with the theoretical design trajectory. Under the operating conditions of crank speed 67 r·min^-1 and forward speed 0.19 m·s^-1, the qualified rate of transplanting angle was 84.20%, the qualified rate of transplanting depth was 90.0%, the coefficient of variation (CV) of planting spacing was 5.8%. The transplanting spacing is stable, the erect degree is high, and the transplanting meets the agronomic requirements. This study can provide reference for the development of mechanized transplanting equipment for multi-fibrous root seedlings.

Introduction: Ginsenosides from Panax ginseng represent a major class of triterpenoid saponins with important biological activities, among which the protopanaxadiol-type ginsenoside Rd is of particular interest. Despite advances in ginsenoside research, the genetic basis and regulatory framework underlying directed Rd biosynthesis remain largely unresolved.

Methods: Here, we integrated genome-wide association studies (GWAS), weighted gene co-expression network analysis (WGCNA), and multi-omics datasets across a diverse ginseng germplasm panel to identify candidate genes associated with natural variation in Rd accumulation. Expression profiling, methyl jasmonate (MeJA) induction assays, and RNA interference (RNAi)-mediated functional validation were employed to characterize the role of the key candidate gene PgUGT-Rd1 within the ginsenoside biosynthetic network.

Results: Five candidate genes were identified as significantly associated with Rd content. PgUGT-Rd1 displayed strong co-expression with core enzymatic genes involved in triterpenoid saponin biosynthesis. MeJA treatment markedly induced PgUGT-Rd1 expression and enhanced Rd accumulation, whereas RNAi-mediated silencing of PgUGT-Rd1 resulted in an approximately 50% reduction in Rd levels, demonstrating its functional contribution to Rd biosynthesis.

Discussion: Our findings establish PgUGT-Rd1 as an important UDP-glycosyltransferase associated with the directed biosynthesis of ginsenoside Rd and provide new insights into the regulatory architecture of ginsenoside metabolic pathways in ginseng. This integrative framework highlights candidate molecular targets for precision breeding and metabolic engineering and advances the understanding of specialized metabolism in medicinal plants.

Embryo abortion severely limits fruit set and yield stability in longan (Dimocarpus longan), yet the upstream physiological triggers and coordinated molecular program remain incompletely defined. Here, we characterized normal seed-forming (NF) and aborted seed-forming (AF) fruits at the critical abortion window by integrating phenotyping, mineral nutrient profiling, embryo-targeted RNA sequencing, and quantitative proteomics, followed by cross-omics association analyses. Orchards with high abortion incidence exhibited markedly low available boron, and aborted embryos displayed a distinctive nutrient-partitioning pattern characterized by severe embryonic boron depletion despite broad changes in other elements. Transcriptome analysis identified 3,865 differentially expressed genes (1,993 upregulated and 1,872 downregulated in AF), with enrichment in pathways related to phenylpropanoid biosynthesis, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, plant hormone signal transduction, and MAPK signaling. Quantitative proteomics revealed 1,518 differentially accumulated proteins (342 increased and 1,176 decreased in AF), highlighting a global trend toward reduced protein abundance in aborted embryos. Integrated transcriptome-proteome analysis detected 374 shared features with strong concordance between mRNA and protein fold changes (93.6% concordant; r = 0.82), reinforcing a coordinated regulatory program at the abortion stage. Across datasets, embryo abortion was associated with disrupted boron-related cell wall processes, altered carbohydrate transport and mobilization, extensive hormone/MAPK rewiring, and pronounced repression of chloroplast-associated programs including photosynthetic light reactions and pigment/tetrapyrrole metabolism, coupled with redox and energy imbalance. qRT-PCR of eight mechanism-anchored candidates supported RNA-seq trends. Together, these results support a model in which embryonic boron depletion and impaired cell wall integrity are associated with, and may contribute to, a cascade of metabolic and signaling reprogramming that culminates in embryo growth arrest and degeneration, providing actionable markers and targets to improve seed development and fruit set in longan.

Introduction: Oat production is constrained by lodging, and silicon input has been shown to promote lignin accumulation in basal internodes and enhance stem mechanical strength and lodging resistance. However, the physiological mechanisms by which silicon input regulates lignin biosynthesis in the second basal internode of oat stems and its effects on lodging-related traits remain unclear.

Method: A split-plot field experiment was conducted in 2024 and 2025, with Mengyan 1 (MY1, lodging-resistant) and Dingyan 2 (DY2, lodging-susceptible) assigned to the main plots and five silicon inputs (0, 30, 60, 90, and 120 kg ha^-1) to the subplots. Lodging-related and physiological traits were analyzed at the grain-filling and milk stages, and the dynamic patterns of lignin-biosynthetic enzyme activities were investigated.

Results: MY1 exhibited the highest lodging resistance at a silicon input of 60 kg ha^-1, and its lignin content increased by 12.5% and 14.6% at the grain-filling and milk stages, respectively, compared to no silicon input. In contrast, DY2 achieved the strongest lodging resistance at an input of 90 kg ha^-1, with lignin content increasing by 12.4% and 17.0% at the two stages, on average in two years. Notably, stem lodging resistance was closely associated with lignin content of the second basal internode in grain-filling (R ² = 0.80) and milk (R ² = 0.64) stages. Silicon primarily enhances stem lodging resistance in oat by promoting lignin accumulation. This effect is achieved through the stimulation of lignin-biosynthetic enzyme activities and the accumulation of key mineral elements in the second basal internode, thereby markedly increasing stem lignin content. Random forest analysis indicated that cinnamyl alcohol dehydrogenase activity at 30 days after jointing made the greatest contribution to lignin biosynthesis, whereas magnesium content at the grain-filling stage was the most influential mineral factor.

Conclusions: Silicon inputs of 60 and 90 kg ha^-1 are recommended for lodging resistant and susceptible oat cultivars respectively, and it enhances lodging resistance by the promotion of lignin accumulation through upregulating enzyme activities and increasing mineral content in the stems.