Frontiers in Plant Science最新文献

To address the problem that current rice fertilization devices rely on experience-based settings of fertilizer application rates and are unable to dynamically adjust according to soil fertility, resulting in low fertilizer use efficiency, a rice side-deep variable-rate fertilization control system based on real-time soil electrical conductivity (EC) detection was designed. First, a three-factor, four-level full factorial experiment was conducted to investigate the effects of soil moisture content, electrode insertion depth, and soil temperature on soil EC, and an EC calibration model was established based on an RBF neural network. Second, a fertilization strategy was developed and a fertilizer application model was constructed based on real-time EC, target yield, and implement forward speed; meanwhile, an incremental PID algorithm was adopted to achieve closed-loop control of variable-rate fertilization with motor speed as the control objective, completing the control system design. Finally, the system was deployed on a pneumatic groove-wheel fertilizer metering device and field experiments were carried out. The performance of the soil EC detection system and the variable-rate fertilization system was validated through EC detection accuracy tests and variable-rate fertilization system response tests. The results showed that the average relative error of EC was 2.70%, the maximum coefficient of variation of the fertilization system response stability was 3.98%, the maximum response time was 1.60 s and the average was 1.28 s, and the average fertilizer reduction rate was 12.39%. These results indicate that the proposed soil EC detection and variable-rate fertilization system can achieve rapid and accurate variable-rate fertilization operations. This study can provide equipment and technical support for rice side-deep variable-rate fertilization.

Introduction: Leaf water potential (Ψ_leaf) is a fundamental physiological metric quantifying tree water status and forest drought stress, yet its measurement remains labor-intensive and destructive. Hyperspectral techniques show great promise for retrieving plant physiological traits; however, robust Ψ_leaf estimation remains limited by three critical factors: unbalanced data distributions, the need for global-local feature synergy, and inherent uncertainty in point-based regression.

Methods: Here, we propose a deep learning framework (CIDL) that integrates: (1) a conditional generative adversarial network (CGAN) to generate balanced synthetic samples across the full Ψ_leaf domain; (2) a feature extractor that combines Inception-ResNet with ACmix (IRAC) to capture local absorption features and long-range spectral dependencies jointly; and (3) a distribution-aware regression network (DARN) to explicitly model the target-variable distribution, thereby enhancing predictive reliability. The model was trained and evaluated using a dataset derived from dehydration experiments on leaves of young Populus euramericana 'I-214' trees, comprising 229 paired Ψ_leaf and hyperspectral reflectance measurements, which were further augmented with 500 CGAN-generated synthetic samples to improve model robustness.

Results: CIDL achieved a prediction accuracy of R ² = 0.78 and RMSE = 0.27 MPa on the test set, clearly outperforming traditional machine learning methods (mean R ² = 0.66, mean RMSE = 0.34 MPa) and yielding a modest yet consistent improvement over mainstream deep learning approaches (mean R ² = 0.76, mean RMSE = 0.28 MPa).

Discussion: These results demonstrate that the proposed CIDL framework provides a generalizable solution for small-sample physiological hyperspectral analysis and offers a reliable, non-destructive pathway for tree water-stress monitoring, with strong potential for applications in smart forestry management.

The C2H2 zinc finger protein (C2H2-ZFP) is a large transcription factor (TF) in plants, widely distributed across plants and playing crucial roles in growth, development, and responses to abiotic stress. However, most studies on the C2H2-ZFP gene family have mainly focused on model plants. In this study, we systematically identified the C2H2-ZFP gene family members in Populus euphratica, a tree species with high tolerance to salt and alkali stress, by analyzing gene localizations, conserved motifs, gene structures, and phylogenetic relationships. A total of 67 members of the P. euphratica C2H2-ZFP gene family were identified and were divided into five subfamilies. Promoter analysis revealed numerous cis-acting elements related to development, hormones, and abiotic stress. Both tandem and segmental duplications were identified as the main driving forces behind the expansion of the PeZFP gene family. Expression profiling showed that most PeZFPs exhibit tissue-specific expression patterns and respond to salt stress. Among them, PeZFP38 was strongly induced by salt stress in roots, stems, and leaves, with expression levels increased by 4.3-10.2-fold, 6-10.4-fold, and 28-63.7-fold, respectively. Subcellular localization demonstrated that PeZFP38 is a nuclear protein. Functional assays showed that transient overexpression of PeZFP38 in poplar leaves enhanced salt tolerance, and stable overexpression of PeZFP38 in Arabidopsis thaliana increased biomass (~68% fresh weight), enhanced antioxidant enzyme activities (e.g., SOD activity reached 1.7-fold that of WT), and reduced oxidative damage (~30% MDA decrease). These results suggest that PeZFP38 may play a role in enhancing salt tolerance by integrating ABA signaling with ROS scavenging systems. Collectively, this study systematically deciphers the evolutionary relationships and expression patterns of the C2H2-ZFP family in P. euphratica. For the first time, it functionally identifies the positive regulatory role of PeZFP38 in salt stress response. These findings provide novel genetic resources and a theoretical basis for understanding stress resistance mechanisms and genetic improvement in forest trees.

The Trichome Birefringence-Like (TBL) gene family encodes polysaccharide acetyltransferases that modify polysaccharide properties, playing key roles in trichome development, cell wall acetylation, and responses to biotic and abiotic stresses. Potato, a globally important crop, frequently faces salinity and drought stress. However, the role of the potato TBL gene family in stress resistance remains unexplored. Using bioinformatics, we identified 72 StTBL genes in the potato DM1-3-516 R44 genome, unevenly distributed across 12 chromosomes. Phylogenetic analysis grouped them into three subfamilies with conserved domains including PC-Esterase, PMR5N, and DUF4283. We further examined gene structure, promoter cis-elements, predicted miRNA targets, GO annotations, and tissue-specific expression. Under both salt and drought stress, we identified several responsive candidate genes from the 72 StTBLs: 10 potential salt-responsive candidates (StTBL 1, StTBL 3, StTBL 16, StTBL 20, StTBL 22, StTBL28, StTBL 58, StTBL 59, StTBL 60 and StTBL 68) and 11 potential drought-responsive candidates (StTBL 1, StTBL 2, StTBL 3, StTBL 12, StTBL 19, StTBL 21, StTBL 22, StTBL 28, StTBL31, StTBL 33 and StTBL 69). This study presents the first genome-wide characterization of the TBL gene family in potato. The findings highlight candidate genes for improving salt and drought tolerance, offering insights for developing stress-resilient potato.

Wheat (Triticum aestivum L.) serves as a critically important staple crop worldwide, and mutation breeding through Cobalt-60 (⁶⁰Co-γ) radiation has been widely adopted as an effective strategy for genetic improvement. In this study, ten wheat cultivars from Shandong, Henan, and Hebei were subjected to ⁶⁰Co-γ irradiation to develop an M₂ mutant population comprising 10,350,000 lines. Systematic screening M₂ mutant population under natural conditions identified 158 freezing-tolerant mutants, 441 saline-alkali-tolerant mutants, and >5,000 mutants with changed yield or quality traits. This population represents a valuable genetic resource for collaborative research and provides a powerful platform for functional genomics studies and breeding applications.

Cistanche Herba (Rou Cong Rong), a critically endangered edible tonic and medicinal plant, is traditionally valued for its nephroprotective and kidney-yang tonifying properties. However, wild populations are declining due to habitat loss, overharvesting, and increasing market demand, leading to widespread adulteration in commercial supplies. Conventional authentication methods, such as morphological examination, photochemical profiling, and ITS/ITS2 barcoding, often fail with processed materials due to DNA degradation. To overcome these limitations, we developed a high-throughput single-nucleotide polymorphism (SNP) genotyping platform that integrates multiplex PCR with MALDI-TOF mass spectrometry, targeting validated nuclear ITS and chloroplast-encoded ribosomal protein large subunit 16 (rpl16) loci. The assay utilizes four diagnostic SNPs specific to C. deserticola, allowing unambiguous differentiation from six adulterants. It demonstrates high sensitivity, detecting 0.07% genomic DNA (6.8 pg/μL) in mixed samples and 1% C. deserticola powder in dried tissue mixture. When validated on 27 dried specimens, the method showed 100% concordance with Sanger sequencing while reducing the total analysis time to approximately 10 hours. By overcoming the resolution limitations of traditional techniques, this approach provides a rapid and scalable solution to combat herbal substitution, support CITES compliance, ensure the integrity of functional foods and traditional medicines.

Introduction: Nitrogen (N)-efficient wheat cultivars achieve higher grain yields with equivalent N fertilizer inputs, and the grain filling character largely determines grain weight (GW) in cereal crops. However, the relationship of grain filling traits and N responsiveness (N_r) in wheat has not been fully evaluated.

Methods: A two-year field experiment evaluated five wheat cultivars across varying N levels (0, 75, 150, and 225 kg N ha^-1) to assess how grain filling traits and N-related characteristics influence N_r.

Results: The results showed that N-responsiveness wheat cultivars exhibited higher grain yields and critical N supply, alongside lower chlorophyll degradation rates (CDR). The direct path coefficient of GW on yield was 0.478, which explained 85.2% of the yield variation and was negatively correlated with other yield components. Across the combinations of cultivar and N supply, the variation in GW was primarily driven by the duration of fast-increase period (T_fast), rather than by the duration of slow-increase period (T _slow) and slight-increase period (T_slight). Furthermore, the sensitivity of T _fast to N supply explained the N_r of grain yield in wheat. Structural equation modeling showed that adequate pre-anthesis N accumulation was the dominant factor driving the extension of T _fast in high N-responsiveness wheat cultivates, secondary to lower CDR, which ultimately resulted in the highest GW. In addition, prolonging T _fast induced enhanced post-anthesis N translocation in wheat, which contributed to higher N use efficiency (NUE).

Discussion: Prolonging the T _fast enhances N responsiveness in wheat grain yield, providing a novel framework for evaluating NUE. This finding also highlights the critical role of elevated N accumulation at anthesis under N fertilization.

The pathogen-related protein 1 (PR-1) family plays an important role in plant response to biotic and abiotic stresses. PR-1 proteins have been studied in many plant species; however, they were not systematically studied in brown algae, which are important components of coastal ecosystems and have great economic value in the aquaculture industry. In the present study, we characterized the structure, evolution and expression of PR-1 proteins in brown algal genomes. A total of 141 PR-1s were identified in the 19 brown algal genomes, with an average of 7 genes in each species. Most PR-1s are acidic, while only 18 PR-1s are basic. Phylogenetic analysis showed that PR-1s in brown algae clustered into five clades, and showed no strong relationship with other lineages, suggesting an ancient origin. All the PR-1s contain a conserved CAP superfamily domain. Some PR-1s contain distinct functional domains, such as the WSC, Blect, and Bulb-type lectin domains, which are involved in carbohydrate binding. Their promoter regions were enriched in stress-response elements, hormone-response elements, growth and development elements. GO and KEGG annotation showed that brown algal PR-1 proteins may be involved in diverse roles and pathways. Moreover, expression analysis shows that some PR-1s, especially basic proteins are responsive to abiotic stress conditions and life stage development, further suggesting they participate in multiple functional pathways. Our results provide important data for future research on the function of brown algal PR-1 family genes.

Reticulate evolution (RE), involving hybridization and related processes, generates network-like rather than strictly bifurcating relationships among lineages and can obscure phylogenetic relationships. Detecting ancient hybridization is particularly challenging, as genomic signals may erode over time. The Malvatheca clade (Malvaceae), marked by multiple paleopolyploidy events since it's estimated origin 66 my, offers a useful model for examining RE. Its three subfamilies-Bombacoideae (with high chromosome numbers, mostly trees), Malvoideae (lower chromosome numbers, mostly herbs), and the recently described Matisioideae-show unresolved relationships, with several taxa of uncertain placement. We conducted a phylogenomic analysis of 69 Malvatheca species via complete plastomes, 35S rDNA cistrons, nuclear low copy genes and comparative repeatome data. Most of the datasets consistently resolved four clades: (I) Bombacoideae, (II) Malvoideae, (III) Matisioideae, and (IV) a heterogeneous assemblage including representatives of Malvoideae, Matisioideae and several incertae sedis taxa. Chromosome numbers were negatively correlated with repeatome diversity: Bombacoideae presented higher counts but lower repeat diversity, possibly reflecting slower repeat evolution associated with woody growth forms. In contrast, clades III and IV showed marked heterogeneity in both chromosome number and repeat composition, which is consistent with a reticulate origin. Overall, our results show evidence of ancient hybridization and polyploidy in shaping Malvatheca evolution. These results highlight that reticulation and genome dynamics, rather than taxonomic boundaries alone, are central to understanding the diversification of Malvatheca.

[This corrects the article DOI: 10.3389/fpls.2024.1332460.].