Frontiers in Plant Science最新文献

Plants live under various biotic and abiotic stress conditions, and to cope with the adversity and severity of these conditions, they have developed well-established resistance mechanisms. These mechanisms begin with the perception of stimuli, followed by molecular, biochemical, and physiological adaptive measures. Tomato (Solanum lycopersicum) is a globally significant vegetable crop that experiences several biotic and abiotic stress events that can adversely impact its quality and production. Mitogen-activated protein kinases (MAPKs) in tomato plants have crucial functions of mediating responses to environmental cues, internal signals, defense mechanisms, cellular processes, and plant development and growth. MAPK cascades respond to various environmental stress factors by modulating associated gene expression, influencing plant hormone synthesis, and facilitating interactions with other environmental stressors. Here, we review the evolutionary relationships of 16 tomato SlMAPK family members and emphasize on recent studies describing the regulatory functions of tomato SlMAPKs in both abiotic and biotic stress conditions. This review could enhance our comprehension of the MAPK regulatory network in biotic and abiotic stress conditions and provide theoretical support for breeding tomatoes with agronomic traits of excellent stress resistance.

Introduction: Optimized photosynthesis and transport of photosynthate from the upper three leaves in a rice plant is critical for yield formation in rice.

Methods: In this study, we selected two high-yielding early-season rice cultivars, i.e. a large-panicle inbred rice Zhongzao39 (ZZ39) and a plural-panicle hybrid rice Lingliangyou268 (LLY268) with high effective panicle number, to study the translocation of photosynthate from the flag and the basipetal 2^nd leaves to the other organs under different nitrogen application scenarios. ¹³CO₂ labeling was study the proportion of newly assimilated carbon partitioned into different organs.

Results: Results demonstrate that the ratio that ¹³C assimilated in the flag leaves and the basipetal 2^nd leaves, and the distribution ratio ¹³C in the organs of ZZ39 and LLY268 cultivars were not affected by nitrogen application. However, at the booting stage, the translocation rate of photosynthate was slower under N150 compared with CK in both flag and the basipetal 2^nd leaves labeled with ¹³C. At the grain filling stage, an average of 51% of photosynthetic products labeled with 13C was translocated to the panicle in both cultivars under CK treatment; in contrast, only 43% of leaf photosynthate was translocated to panicles in the N150 treatment. At maturity, the photosynthate labeled with ¹³C distribution ratio in the panicle was greater in the basipetal 2^nd leaves than in the flag leaves for ZZ39, whereas the opposite was observed in LLY268. These different photosynthate allocation patterns and their responses to nitrogen application were linked with their corresponding tiller number and number of grains per panicle.

Discussion: This study shows that early-season rice has the ability to flexibly adapt their carbon and nitrogen allocation patterns to gain optimized yield components for higher yield under different nitrogen status. Early season rice can be used as a model system to study the growth strategy selection of plants to changing environment conditions.

The rapid increase in global population poses a significant challenge to food security, compounded by the adverse effects of climate change, which limit crop productivity through both biotic and abiotic stressors. Despite decades of progress in plant breeding and genetic engineering, the development of new crop varieties with desirable agronomic traits remains a time-consuming process. Traditional breeding methods often fall short of addressing the urgent need for improved crop varieties. Genome editing technologies, which enable precise modifications at specific genomic loci, have emerged as powerful tools for enhancing crop traits. These technologies, including RNA interference, Meganucleases, ZFNs, TALENs, and CRISPR/Cas systems, allow for the targeted insertion, deletion, or alteration of DNA fragments, facilitating improvements in traits such as herbicide and insect resistance, nutritional quality, and stress tolerance. Among these, CRISPR/Cas9 stands out for its simplicity, efficiency, and ability to reduce off-target effects, making it a valuable tool in both agricultural biotechnology and plant functional genomics. This review examines the functional mechanisms and applications of various genome editing technologies for crop improvement, highlighting their advantages and limitations. It also explores the ethical considerations associated with genome editing in agriculture and discusses the potential of these technologies to contribute to sustainable food production in the face of growing global challenges.

Introduction: The color of Clausena lansium L. Skeels cv. Jixin fruit peel is brown (BP), while the mutant cv. Zijin had purple fruit peels (PP). The coloration of the peels was attributed to significant differences in chlorophyll, carotenoid, and anthocyanin content between BP and PP.

Methods: This study investigates the biosynthetic metabolic activities in the brown and purple peels of Clausena lansium L. Skeels using metabolomics and transcriptomics. It aims to identify metabolic pathways and differentially expressed genes related to flavonoids and anthocyanins biosynthesis.

Results: The PP (purple peel) has higher levels of a-carotene and b-carotene but lower levels of chlorophyll a, chlorophyll b, and lutein compared to BP. Zeaxanthin was absent from both peels, suggesting that the b-carotene hydroxylase enzyme is not active. Both peels contain delphinidin-based (Dp) and cyanidin-based (Cy) anthocyanins, but not pelargonidin-based (Pg). The total anthocyanin content and the Dp/Cy ratio are higher in PP than in BP. The delphinidin, cyanidin, and mallow derivatives in the PP were significantly higher than in the BP. The increase of total anthocyanin content and Dp/Cy ratio may be the main reason for the peel color changing from brown to purple. The significant increase of F3H expression in purple peels suggested a higher efficiency of catalyzing the conversion of naringenin into dihydroflavonols in the PP, leading to the higher content of total anthocyanin. Despite the significant increase of FLS expression in PP, the contents of kaempferol, quercetin, and myricetin significantly decreased, suggesting that the increase of FLS expression did not lead to an increase in flavonol biosynthesis.

Discussion: The competition between F3'H and F3'5'H may determine the ratio of Dp/Cy, the higher levels of F3'H, F3'5'H, and UFGT expression, lead to the increase accumulation of total anthocyanin and Dp/Cy in PP. The deficiency of Pg in both peels resulted from the substrate specificity of the DFR enzyme. The research also describes the transition in color from BP to PP and details of the biosynthetic pathways for carotenoids and anthocyanins, elucidating the molecular processes underlying anthocyanin production.

Tomatoes are highly susceptible to numerous diseases that significantly reduce their yield and quality, posing critical challenges to global food security and sustainable agricultural practices. To address the shortcomings of existing detection methods in accuracy, computational efficiency, and scalability, this study propose TomatoGuard-YOLO, an advanced, lightweight, and highly efficient detection framework based on an improved YOLOv10 architecture. The framework introduces two key innovations: the Multi-Path Inverted Residual Unit (MPIRU), which enhances multi-scale feature extraction and fusion, and the Dynamic Focusing Attention Framework (DFAF), which adaptively focuses on disease-relevant regions, substantially improving detection robustness. Additionally, the incorporation of the Focal-EIoU loss function refines bounding box matching accuracy and mitigates class imbalance. Experimental evaluations on a dedicated tomato disease detection dataset demonstrate that TomatoGuard-YOLO achieves an outstanding mAP50 of 94.23%, an inference speed of 129.64 FPS, and an ultra-compact model size of just 2.65 MB. These results establish TomatoGuard-YOLO as a transformative solution for intelligent plant disease management systems, offering unprecedented advancements in detection accuracy, speed, and model efficiency.

Introduction: Ratoon rice, as a high-efficiency rice cultivation mode, is widely applied around the world. Mechanical righting of rolled rice stubble can significantly improve yield in regeneration season, but lack of automation has become an important factor restricting its further promotion.

Methods: In order to realize automatic navigation of the righting machine, a method of fusing an instance segmentation model and a monocular depth prediction model was used to realize monocular localization of the rolled rice stubble rows in this study.

Results: To achieve monocular depth prediction, a depth estimation model was trained on training set we made, and absolute relative error of trained model on validation set was only 7.2%. To address the problem of degradation of model's performance when migrated to other monocular cameras, based on the law of the input image's influence on model's output results, two optimization methods of adjusting inputs and outputs were used that decreased the absolute relative error from 91.9% to 8.8%. After that, we carried out model fusion experiments, which showed that CD (chamfer distance) between predicted 3D coordinates of navigation points obtained by fusing the results of the two models and labels was only 0.0990. The CD between predicted point cloud of rolled rice stubble rows and label was only 0.0174.

Carrot (Daucus carota L.) is one of the most important root crops grown worldwide and in Ethiopia. However, its production and productivity are low due to a lack of improved varieties and unbalanced fertilizer rates, among other factors. The field experiment was, therefore, conducted to determine the performance of carrot varieties through blended fertilizer rates at Gondar district for a consecutive period of two years. The treatment consisted of six rates of blended NPSB (Nitrogen, phosphorus, sulfur and Boron) fertilizer (0, 40.6, 81.3, 122, 162.3, and 203.4 kg ha^-1) and two carrot varieties (Haramay-I and Nantes), which were laid out in a randomized complete block design with three replications. The main effect of blended NPSB received in 162.3 kg ha^-1 obtained the highest root diameter (3.38 cm), root length (20.93 cm), and root volume (110.60 mm). The main effect of the year was also the maximum number of leaves (10.3), root diameter (2.96 cm), root length (20.09 cm), and root volume (89.20 mm) recorded from the 2021 planting year. On the other hand, in the interaction of variety and NPSB, the highest root fresh weight (134.48 g plant^-1) was obtained from the Haramaya-I variety and the application of 162.3 NPSB kg ha^-1, while the lowest (57.13 g plant^-1) was recorded by the Nantes variety with control. The highest dry matter (13.67%), marketable (50.77 t ha^-1) and total (55.32 t ha^-1) root yields were recorded from the interaction of 162.3 kg NPSB ha^-1 and Haramaya-I variety. Therefore, the planting season and varietal selection should be considered in the carrot production area.

The acidic taste of Mei fruit (Prunus mume) is a major contributor to its quality, but its formation mechanism remains unclear. Here, we unraveled the networks of organic acid and flavonoid metabolism in two Mei fruit. The results showed that the differentially expressed genes were mainly concentrated in the processes of carbohydrate derivative binding, carboxylic acid, and organic acid metabolism. While the differentially accumulated metabolites were mainly associated with flavone and flavonol biosynthesis and amino acid and carbon metabolism. Moreover, we identified key metabolites, such as citric and succinic acids, which may be central to the development of acidity in Mei fruit, and determined that they are under the regulatory influence of specific genes, including galactinol-sucrose-galactosyltransferase 5, mitogen-activated protein kinase kinase kinase NPK1-like, glutamate receptor, and chalcone isomerase. Furthermore, transcription factors ERF027, bHLH92, bHLH35, and WRKY23 were identified as potential pivotal regulators within these networks. These results provide new insights into the metabolic regulation of acidity and flavonoid in Mei fruit.

Introduction: Salt stress has emerged as a predominant abiotic factor that jeopardizes global crop growth and yield. The plant hormone salicylic acid (SA) has notable potential in mitigating salt toxicity, yet its mechanism in enhancing the salinity tolerance of tobacco plants is not well explored.

Methods: This study aimed to assess the potential benefits of exogenous SA application (1.0 mM) on tobacco seedlings subjected to saline soil conditions.

Results: The foliar spray of SA partially mitigated these salt-induced effects, as evidenced by a reduction of malondialdehyde content, and improvements of leaf K⁺/Na⁺ ratios, pigment biosynthesis, and electron transport efficiency under NaCl stress. Additionally, SA increased the contents of total phenolic compound and soluble protein by 16.2% and 28.7% to alleviate NaCl-induced oxidative damage. Under salt stressed conditions, the activities of antioxidant enzymes, including superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase increased by 4.2%~14.4% in SA sprayed tobacco seedlings. Exogenous SA also increased ascorbate and glutathione levels and reduced their reduced forms by increasing the activities of glutathione reductase, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase. qRT-PCR analysis revealed that the key genes regulating SA biosynthesis, carbon assimilation, the antioxidant system and the ascorbate-glutathione cycle were activated by SA under conditions of salt stress.

Discussion: Our study elucidates the physiological and molecular mechanisms of exogenous SA in enhancing plant salt tolerance and provides a practical basis for crop improvement in saline environments.

As soil becomes more acidic, aluminum toxicity has emerged as a key issue impacting seed germination and crop productivity in such environments. Therefore, it is urgent to investigate the mechanism of the influence of aluminum stress on germination. In this study, we focused on one of the major bioenergy crops-rapeseed. Seeds of aluminum-sensitive (S) and aluminum-resistant (R) lines screened from the recombinant inbred lines (RILs) population of rapeseed were treated with 80 µg·ml^-1 AlCl₃ (ST, RT). Purified water served as the control (SC, RC). On the 3rd, 5th, and 7th day after treatment, the root tissue was collected for transcriptome sequencing. Utilizing MapMan software, the genes showing differential expression in S and R lines were assigned to the aluminum stress signaling pathway, resulting in the identification of 1036 genes. By weighted gene co-expression network analysis (WGCNA), five co-expressed gene modules associated with aluminum stress were discovered. A total of 332 candidate genes were screened by combining the genes related to aluminum stress signal transduction pathways with the module hub genes. Among them, 26 key genes were located in quantitative trait loci (QTL) with confidence intervals for germination-related traits of rapeseed under aluminum stress, and primarily distributed in 11 QTL regions, such as qRDW-A09-1, qRDW-A10-1 and qRGV-A01-2, they were associated with relative root length (RRL), relative root dry weight (RDW), relative germination vigor (RGV) and relative bud length (RBL). The roles included transcription regulation, stress protein production, redox processes, hormone signaling, cell wall alteration, and calcium-based signal transmission. Compared with the R line, the S line exhibited quicker and stronger activation of genes related to aluminum stress signal transduction, suggesting that the S line was more responsive to aluminum stress. This research offers an empirical basis for identifying aluminum-resistant rapeseed varieties and investigating the molecular regulation of aluminum tolerance during germination.