Frontiers in Plant Science最新文献

Extracting the navigation line of crop seedlings is significant for achieving autonomous visual navigation of smart agricultural machinery. Nevertheless, in field management of crop seedlings, numerous available studies involving navigation line extraction mainly focused on specific growth stages of specific crop seedlings so far, lacking a generalizable algorithm for addressing challenges under complex cross-growth-stage seedling conditions. In response to such challenges, we proposed a generalizable navigation line extraction algorithm using classical image processing technologies. First, image preprocessing is performed to enhance the image quality and extract distinct crop regions. Redundant pixels can be eliminated by opening operation and eight-connected component filtering. Then, optimal region detection is applied to identify the fitting area. The optimal pixels of plantation rows are selected by cluster-centerline distance comparison and sigmoid thresholding. Ultimately, the navigation line is extracted by linear fitting, representing the autonomous vehicle's optimal path. An assessment was conducted on a sugarcane dataset. Meanwhile, the generalization capacity of the proposed algorithm has been further verified on corn and rice datasets. Experimental results showed that for seedlings at different growth stages and diverse field environments, the mean error angle (MEA) ranges from 0.844° to 2.96°, the root mean square error (RMSE) ranges from 1.249° to 4.65°, and the mean relative error (MRE) ranges from 1.008% to 3.47%. The proposed algorithm exhibits high accuracy, robustness, and generalization. This study breaks through the shortcomings of traditional visual navigation line extraction, offering a theoretical foundation for classical image-processing-based visual navigation.

The microfilament cytoskeleton, formed by the process of actin polymerization, serves not only to support the morphology of the cell, but also to regulate a number of cellular activities. Actin-depolymerizing factors (ADFs) represent a significant class of actin-binding proteins that regulate the dynamic alterations in the microfilament framework, thereby playing a pivotal role in plant growth and development. Additionally, they are instrumental in modulating stress responses in plants. The ADF gene family has been explored in various plants, but there was a paucity of knowledge regarding the ADF gene family in alfalfa (Medicago sativa), which is one of the most significant leguminous forage crops globally. In this study, a total of nine ADF genes (designated MsADF1 through MsADF9) were identified in the alfalfa genome and mapped to five different chromosomes. A phylogenetic analysis indicated that the MsADF genes could be classified into four distinct groups, with members within the same group exhibiting comparable gene structures and conserved motifs. The analysis of the Ka/Ks ratios indicated that the MsADF genes underwent purity-based selection during its evolutionary expansion. The promoter region of these genes was found to contain multiple cis-acting elements related to hormone responses, defence, and stress, indicating that they may respond to a variety of developmental and environmental stimuli. Gene expression profiles analyzed by RT-qPCR experiments demonstrated that MsADF genes exhibited distinct expression patterns among different organs. Furthermore, the majority of MsADF genes were induced by salt and drought stress by more than two-fold, with MsADF1, 2/3, 6, and 9 being highly induced, suggesting their critical role in resistance to abiotic stress. These results provide comprehensive information on the MsADF gene family in alfalfa and lay a solid foundation for elucidating their biological function.

This study aimed to uncover salt-tolerant eggplant (Solanum melongena L.) genotypes and accessions. Crop wild relatives (S. macrocarpon L., S. linnaeanum, S. incanum L., S. insanum L., S. sisymbriifolium Lam.), commercial varieties (Topan374, Kemer, Amadeo, Faselis, Bildircin), and local genotypes (TB, BB, MK, AH) were investigated under 150 mM NaCl stress. The experiment was set in a completely randomized block design with three replications. Morphological and biochemical parameters were studied to distinguish salt-tolerant genotypes. Wild relatives have species-specific growth features; thus, the salt tolerance levels of morphologic features such as plant height and leaf area were found inappropriate to be compared. In eggplant, Na⁺ is a majorly harmful ion and there is a negative correlation between leaf Na⁺ content and plant tolerance index. The low Na⁺ concentration in roots of BB and S. linnaeanum caused high K⁺ and Ca²⁺ concentrations in their leaves. A plant with high proline accumulation displays greater tolerance under stress conditions. The proline content of S. linnaeanum, S. incanum L., and MK was analyzed to be higher than the others. Additionally, the lowest malondialdehyde (MDA) increases were observed in S. linnaeanum, TB, and S. incanum L. Moreover, positive correlations were spotted between 0-5 scale values and MDA and Na⁺ level in shoots by correlation analysis. Strong correlations between proline accumulation-S. linnaeanum and MDA accumulation-AH were revealed by principal component analysis (PCA). In terms of results, the most salt-tolerant, S. linnaeanum, S. incanum L., BB, and MK, will be employed in future breeding studies to improve salt-tolerant inbred lines and varieties through interspecific hybridization.

Introduction: Hemipteran gall vascular traits result from the access, piercing, and sucking of the inducer mouth parts directly in the xylem and phloem conductive cells. Herein, our focus relies on mapping the features of phloem cells in the proximal, median, and distal regions of Malus pumila stem galls and adjacent galled stems.

Methods: Phloem cells were dissociated from gall fragments, the stem portions above and below the galls, and the proximal and distal regions of M. pumila stem galls. were measured. The comparison of the higher length and diameter of the sieve tube elements (STE) was evaluated considering the priority of nutrient flow to gall portions.

Results: In the M. pumila - E. lanigerum system, there were no significant differences in the dimensions of the STE in the galls compared with those of the stem portions above and below the galls.

Discussion: At the cytological level, the callose deposited in gall STE and the decrease in the cell lumen area in the stem portion above the gall due to thickened nacreous cell walls have implications for nutrient flow. Peculiarly, the smaller sieve pores in the sieve plates of the STE located in the galls and stem portions above and below them and the deposition of P-protein in the stem portions below the galls limit the bidirectional transport of nutrients, benefiting the transport of photoassimilates to the gall proximal region and reducing the vigor of apple tree stems.

A comprehensive understanding of the genetics of resistance is essential for developing an effective breeding strategy to create germplasm resistant to Fusarium Ear Rot. This study aimed to determine the general combining ability (GCA), specific combining ability (SCA), and heritability of resistance to infection by Fusarium verticillioides in tropical maize. Using the North Carolina II mating design, six inbred lines as females and seven as males were crossed to produce 42 hybrids, which were evaluated across five environments using artificial inoculation. At harvest, the hybrids were scored for Fusarium Ear Rot (FER) infection using a 1-9 severity scale. Significant GCA effects for the parents and SCA effects for the hybrids were observed. The narrow-sense heritability estimate was 0.22, while the broad-sense heritability was 0.73, and the additive genetic effects, as represented by GCA (m+f), were more significant than non-additive effects. The inbred parents JPS25-13, JPS26-125, JPS26-86, JPS25-11, JPS25-5, JPS25-7, and JPS25-9 were identified as the best general combiners for FER resistance. These lines, with favorable general combining ability effects for resistance to Fusarium verticillioides, are strong candidates for breeding resistant varieties.

The functioning of ecosystem services in water-limited grassland ecosystems is significantly influenced by precipitation characteristics. This study aims to quantitatively assess the impact of different precipitation scenarios on grassland productivity using the APSIM model. Historical weather data from 1968 to 2017 and observational data from three types of steppes (meadow, typical, and desert steppe) in Inner Mongolia Autonomous Region from 2004 to 2010 were collected to determine key crop variety parameters for the APSIM model. The effects of annual precipitation, seasonal precipitation, and inter-growing season precipitation variability on aboveground net primary production (ANPP) and precipitation utilization efficiency (PUE) in different types of steppes were investigated by scenario simulation by validated model. The simulated ANPP shows distinctive responses to the changed rainfall characteristics, where the influence of precipitation decreasing is more evident than precipitation increasing by the same precipitation change. Regarding steppe types, the typical steppe responded more strongly to increased precipitation, while decreased precipitation led to higher decline in ANPP for desert steppe. Precipitation during growing seasons caused more significant change than dormancy seasons regarding ANPP, however, PUE show the opposite trend, indicating the contribution of unit level precipitation changes to productivity is significant during dormancy seasons. The effect of changing precipitation during middle growing season outweighed that of late growing season and early growing season, and the positive effect of increasing precipitation were more pronounced in typical steppe and desert steppe if facing early growing season precipitation increase in the future. The research results provide a theoretical basis and technical support for optimizing grassland production management.

Escalating population growth and climate change pressures on crop production necessitate agricultural innovation to ensure food security and sustainability. Plant molecular farming (PMF), which uses genetically modified (GM) plants to produce high-value proteins for food products, offers a promising solution. PMF products, particularly those that express an animal protein in seed and grain crops, have the potential to substantially benefit U.S. and global agriculture, food systems, economies, and the environment. Farmers can diversify and generate increased revenue streams, while consumers gain access to affordable proteins beyond those currently available. However, the development and commercialization of PMF products, especially those expressing allergenic animal proteins, require careful consideration of existing stewardship guidelines and best practices. Current GM plant stewardship practices must be thoroughly assessed to identify and address any gaps, ensuring that PMF products maintain identity preservation and containment throughout their lifecycle. Implementing a fit-for-purpose closed-loop system (CLS) is crucial for effectively identifying, managing, and mitigating the potential risks and liabilities associated with PMF product development, production, and processing. A CLS framework for PMF products expressing animal proteins should integrate existing best practices from Excellence Through Stewardship and applicable third-party guidelines, including by way of example ISO standards, Good Manufacturing Practices, Hazard Analysis and Risk-Based Preventive Controls, Hazard Analysis and Critical Control Points, and Safe Quality Food, as well as newly designed controls to address potential PMF-specific risks. This comprehensive approach maximizes containment, identity preservation, regulatory compliance, traceability, incident response capabilities, and continuous improvement across the product lifecycle. While customization is required based on each PMF product developer's specific product and operations, this paper examines industry best practices and describes CLS components that a PMF developer should consider in designing a robust, bespoke CLS to maintain identity preservation and product containment. Such a system will optimize for product quality and integrity while preventing commingling with commodity supplies and any associated market disruption while also addressing food safety. By implementing these rigorous systems, the PMF industry can realize its potential to contribute significantly to sustainable agriculture and food security.

Plant resistance inducers that activate plant defense mechanisms may be useful in reducing agrotoxic use. Lettuce is among the most economically important leafy vegetable crops in the world. Since lettuce propagates through seeds, the use of high-quality seeds is extremely important for establishing the crop. Several studies have demonstrated the potential of alternative methods of seed treatment with the aim of increasing productivity. Based on this premise, we tested the effect of the rBASIDIN effector regarding its ability to induce germination and physiological changes in lettuce seedlings through seed treatment. The seeds were treated for 30 min by soaking with 50 µg mL^-1, 75 µg mL^-1 and 100 µg mL^-1 of the recombinant effector protein rBASIDIN. Seeds treated with distilled water and 10 mmol of Tris-HCl served as controls. The physiological parameters evaluated were germination percentage at 4 and 7 days, seedling length (aerial part and root), dry and fresh mass, electrical conductivity, and enzymatic activity. Seeds treated with 50 and 75 µg mL^-1 of rBASIDIN germinated earlier than the controls. Treatment with rBASIDIN at a concentration of 50 µg mL^-1 resulted in seedlings with an average root length of 1.51 cm, while the average lengths of the controls (H₂O and buffer) were 0.86 and 0.70 cm respectively. Seed treatment with rBASIDIN caused an increase in the fresh and dry weight of the plants. The lowest electrolyte leakage was detected in seeds treated with the three concentrations of rBASIDIN compared to the controls. Regarding the activity of defense enzymes, seedlings treated with rBASIDIN at lower concentrations showed higher chitinase and β-glucanase activity compared to the controls. The results indicated that the rBASIDIN effector plays an important signaling role in lettuce seeds, since small doses are already sufficient to induce changes in physiological parameters to obtain more vigorous plants.

As a vital component of the desert ecological protection system, the edge-locked forests of the Kubuqi Desert play a crucial role in mitigating wind erosion, stabilizing sand, maintaining soil and water, and restricting desert expansion. In this paper, six types of standard protection forests in the Kubuqi Desert, namely Salix psammophila (SL), Elaeagnus angustifolia (SZ), Salix matsudana (HL), Corethrodendron fruticosum+Salix psammophila (YC + SL), Caragana korshinskii + Populus simonii (XYY + NT), and Elaeagnus angustifolia + Salix matsudana (SZ + HL), were investigated. Notably, the vertical differentiation patterns of soil carbon (C), nitrogen (N), phosphorus (P), and ecological stoichiometric ratios, as well as soil particle size features within the 0-100-cm soil layer under protection forests with different allocation modes, were systematically and comprehensively analyzed. The study's findings showed that: (1) Among the six configuration types, SZ, NT + XYY, and SL exhibited higher soil SOC and TN concentrations. Both soil SOC and TN content decreased with increasing soil depth, whereas soil TP content displayed no considerable variation among different stand types or soil depths. (2) Based on the N/P threshold hypothesis, N was the limiting nutrient element for the growth of edge-locked forests in the region. (3) The understory soils of different configurations of edge-locked forests mainly comprised sand. The silt and clay contents of SL and NT + XYY were substantially higher than those of the other four configurations. The vertical distribution patterns of particle size and parameter characteristics had variations. (4) Soil C, N, P, and stoichiometric characteristics are affected by vegetation type, soil depth, and soil texture. In conclusion, SZ and SL can be used as the dominant tree species in the edge-locked forests of the Kubuqi Desert, and the NT + XYY mixed forest configuration pattern displays the most apparent soil improvement effect. This study's findings offer a scientific reference and foundation for restoring vegetation and enhancing the ecological environment in desert regions. In addition, they provide a theoretical foundation for establishing and managing edge-locked forests.

MADS-box genes are classified into five categories: ABCDE, including SEP1, SEP2, SEP3, SEP4, and other homologous genes, which play important roles in floral organ development. In this study, the cDNA sequence of the HrSEP1 gene was cloned by RT-PCR and confirmed that this gene belongs to the MADS-box gene family. In addition, subcellular localization experiments showed that the HrSEP1 protein was localized in the nucleus. We verified the interaction of HrSEP1 with HrSOC1, HrSVP, and HrAP1 using yeast two-hybrid and bimolecular fluorescence complementation assays. These genes jointly regulate the growth and development of floral organs. We also found a strong synergy between HrSEP1 and AP1 genes in sepals, petals, and stamens by transgenic methods and fluorescence quantitative PCR, suggesting that HrSEP1 and AP1 may co-regulate the development of these structures. In conclusion, the expression of HrSEP1 has a certain effect on the development of floral organs, and these findings lay the foundation for further research on the biological functions of MADS transcription factors in Hippophae rhamnoides.