Frontiers in Plant Science最新文献

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.].

Abiotic stresses such as drought, salinity, heavy-metal toxicity, and photooxidative damage severely constrain global crop productivity, a challenge intensified by ongoing climate change. The apocarotenoid β-cyclocitral (β-CC), produced via both carotenoid cleavage dioxygenase (CCD)-mediated and reactive oxygen species (ROS)-driven oxidation, has emerged as a conserved signaling molecule that enhances plant adaptation to environmental stress. β-CC mitigates oxidative damage, promotes root system remodeling, and activates detoxification pathways through ABA-independent mechanisms involving the transcriptional regulators MBS1 and SCL14. Its oxidized derivative, β-cyclocitric acid (β-CCA), extends this signaling framework by modulating the cyclin kinase inhibitor SMR5 and the cytochrome P450 gene CYP81D11, thereby strengthening photosynthetic capacity, ROS control, and developmental reprogramming under drought and high-light stress. Beyond vegetative responses, β-CC also enhances seed vigor and longevity through apocarotenoid-dependent regulation of antioxidant activity and aquaporin expression. Comparative studies across Arabidopsis, rice, tomato, quinoa, and peach reveal both conserved and species-specific outcomes, underscoring the versatility of β-CC/β-CCA signaling. The broad occurrence of these apocarotenoids highlights their potential as natural biostimulants and molecular tools for improving stress resilience in crops. Although direct studies in soybean remain limited, conserved orthologs and signaling components point to promising translational opportunities. Future research should clarify the dynamics of β-CC and β-CCA accumulation, validate conserved gene networks such as MBS1/SCL14/CYP81D11, and develop stable, field-compatible delivery systems. Integrating mechanistic and physiological insights from model species will accelerate the application of β-CC-based strategies for climate-resilient agriculture.

Background: Drought is a crucial abiotic stress factor affecting the growth and development of cotton, and there is significant differentiation in drought resistant among different cotton varieties. To reveal the drought resistance mechanisms of four cotton varieties, this study conducted a systematic analysis across multiple stages and multiple indicators.

Methods: In this study, two drought resistant varieties (J206-5 and Jiumian 20) and two drought sensitive varieties (Xinluzhong 77 and Xinluzhong 67) were selected as experimental materials for seed germination, drought related gene expression during seedling stage, and photosynthetic indicators during flower and boll stage.

Results: The six germination indicators of four cotton varieties showed a decreasing trend with the increase of PEG6000 concentration. Under 10% PEG6000 treatment, the relative germination potential, relative germination rate, relative germination index, and relative root fresh weight of drought resistant varieties were significantly higher than those of drought sensitive varieties. Under drought stress until July 19th, the Pn, Tr, and SPAD of drought resistant varieties were significantly higher than those of drought sensitive varieties. Under drought stress until August 19th, the Ci and SPAD of drought resistant varieties were significantly higher than those of drought sensitive varieties, and the Pn of drought resistant varieties was significantly higher than that of drought sensitive variety Xinluzhong 67. When drought resistant varieties were subjected to drought stress for 8d, except for the GhPPO-3 gene, the expression levels of the other 8 genes were significantly upregulated and reached their maximum values, and the expression levels were significantly higher than those of drought sensitive varieties.

Conclusion: Under drought stress, drought resistant cotton varieties exhibit better seed germination, photosynthesis, and expression levels of drought related genes. This study provides a theoretical basis for cotton drought resistance breeding.

Fusarium head blight (FHB) is a major disease of small grain cereals that is particularly damaging to wheat and can result in yield losses of up to 80%. Resistance to FHB in wheat is broadly classified as resistance to initial infection (type I) or resistance to disease spread within the spike (type II). A high level of type I FHB resistance was reported in an accession of wheat wild relative Triticum timopheevii. Hexaploid wheat-T. timopheevii introgression lines carrying a segment of the short arm of chromosome 3G (Chr3G) of this accession expressed high levels of FHB resistance following spray inoculation. Further analyses of these introgression lines showed that the Chr3G segment confers a potent type II resistance, accompanied by improved grain weight retention and reduced deoxynivalenol (DON) accumulation in grain. These results indicate that Chr3G resistance has the potential to dramatically reduce FHB susceptibility and DON accumulation in grain in wheat cultivars. An introgression of a segment of Chr7A^t into the short arm of Chr7A also enhanced type II FHB resistance.

Introduction: In the water-limited Loess Plateau of China, wheat productivity faces severe constraints. This study investigates the physiological and quality determinants of yield and protein content across multiple winter wheat cultivars to identify key breeding targets for dryland systems.

Methods: Eleven cultivars were analyzed for soil water storage dynamics, dry matter accumulation and translocation, nitrogen use efficiency, and grain quality parameters, including volatile flavor compounds.

Results: High yield potential was driven by superior pre-anthesis nitrogen assimilation and substantial post-anthesis dry matter remobilization. The highest-yielding cultivar (YH-805) achieved this through a greater number of grains per spike. Conversely, higher grain protein content (e.g., in YH-618) was linked to enhanced post-flowering nitrogen translocation. A fundamental yield-protein trade-off was confirmed. The medium-yield, high-protein cultivar YH-115 exhibited the most favorable flavor profile, associated with key volatile compounds like octanal and hexanal.

Discussion: The results demonstrate that yield and quality are governed by distinct pre- and post-anthesis resource allocation strategies. Targeted breeding for specific traits-such as pre-anthesis nitrogen uptake for yield or post-anthesis nitrogen translocation for protein-can help optimize for either enhanced productivity or superior end-use quality in dryland wheat systems.

Automated pest detection is essential for timely and accurate crop monitoring, yet many existing approaches rely on manual inspection or computationally heavy models that struggle with small and variable datasets. To address these challenges, we introduce an enhanced ConvNeXt-Tiny-based framework that incorporates a tailored preprocessing pipeline to improve feature quality and overall performance. The model is evaluated on an RGB image dataset of 3,000 date palm leaf samples across four classes (Bug, Dubas, Healthy, Honey). Its performance is compared against two custom baselines, CNN-Attention and ResNet13-Attention, as well as state-of-the-art models including ViT, ECA-Net, and the standard ConvNeXt-Tiny. Experimental results show that our preprocessing-augmented ConvNeXt-Tiny achieves the highest accuracy, precision, recall, and F1-score, outperforming both custom and state-of-the-art baselines. These findings demonstrate the effectiveness of the proposed lightweight solution for scalable and high-accuracy pest detection in precision agriculture.