The β-glucosidases (BGLUs) of Glycoside Hydrolase Family 1 (GH1) exhibit essential functions in plant secondary metabolism and stress responses, mediated by their dual catalytic capabilities in hydrolysis and transglycosylation. This study identified 149 BGLU family members within B. napus (Brassica napus L.), which were systematically categorized into 10 distinct subgroups. Subsequent characterization encompassed detailed examination of their motif composition, chromosomal distribution, gene collinearity, selection pressure, and expression profiling. Transient overexpression of BnBGLU77 in N. benthamiana (Nicotiana benthamiana), combined with untargeted metabolomics analysis, revealed pronounced modulatory effects on the degradation and accumulation of β-glucosidic compounds, suggesting potential roles of the protein encoded by BnBGLU77 in metabolic homeostasis and stress response mechanisms. These experimental results first validated the bidirectional catalytic activity of a BGLU enzyme in B. napus, while simultaneously advancing fundamental understanding of BnBGLU gene functions and providing new insights for developing stress-resistant rapeseed cultivars through targeted genetic improvement.

The BAHD acyltransferase family plays a critical role in plant secondary metabolism by catalyzing acyl transfer reactions that are essential for synthesizing metabolites involved in environmental adaptation. However, systematic investigation of this superfamily in Brassica napus has not been reported. In this study, 158 BnaBAHD genes were identified by comprehensive analyses of evolutionary relationships, motif structures, chromosomal distribution, gene collinearity, and selection pressures, and these genes were phylogenetically classified into five clades harboring conserved catalytic domains (HXXXD and DFGWG). Transient overexpression combined with metabolomic profiling demonstrated that two homologous seed-specific Clade V members, BnaBAHD040 and BnaBAHD120, which exhibited elevated expression during late seed development, significantly enhanced the accumulation of acylated metabolites contributing to biotic/abiotic stress resistance. This study provides the first experimental validation of the catalytic functions of BAHD enzymes in B. napus, establishing a theoretical foundation for leveraging this gene family in genetic improvement to develop novel rapeseed cultivars with enhanced stress tolerance and yield.

In the production of a digital orthophoto map (DOM) from unmanned aerial vehicle (UAV)-acquired overlapping images, some anomalies such as texture stretching or data holes frequently occur in water areas due to the lack of significant textural features. These anomalies seriously affect the visual quality and data integrity of the resulting DOMs. In this study, we attempted to eliminate the water surface anomalies in an example DOM via replacing the entire water area with an intact one that was clipped out from one single UAV image. The water surface scope and boundary in the image was first precisely achieved using the multisource seed filling algorithm and contour-finding algorithm. Next, the tie points were selected from the boundaries of the normal and anomalous water surfaces, and employed to realize their spatial alignment using affine plane coordinate transformation. Finally, the normal water surface was overlaid onto the DOM to replace the corresponding anomalous water surface. The restored water area had good visual effect in terms of spectral consistency, and the texture transition with the surrounding environment was also sufficiently natural. According to the standard deviations and mean values of RGB pixels, the quality of the restored DOM was greatly improved in comparison with the original one. These demonstrated that the proposed method had a sound performance in restoring abnormal water surfaces in a DOM, especially for scenarios where the water surface area is relatively small and can be contained in a single UAV image.

The root system is vital for Brassica napus water/nutrient uptake and anchorage, highlighting the importance of identifying root development genes (RDGs). In this study, we identified 218 RDGs in B. napus through homology-based retrieval. Phylogenetic analysis of 22 representative species revealed that the RDGs are widely present in plants ranging from aquatic algae to angiosperms. RDGs in B. napus expanded through whole-genome duplication (WGD) events between Brassica rapa and Brassica oleracea ancestors and smaller duplications specific to B. napus. Promoter analysis identified 115 cis-elements, mainly abiotic stress-related and light-responsive. Transcription factor networks showed regulation by BBR-BPC, MIKC_MADS, AP2, and GRAS families. Transcriptome analysis under multiple stresses revealed that low nitrogen (LN) induced the most pronounced changes, with >50% (109/218) of RDGs differentially expressed in roots. Furthermore, we screened the BnaSHR-6 gene, which is co-localized in both primary roots (PR) and lateral roots (LR), and responds strongly to LN. Phenotypic analysis revealed that the BnaSHR-6 gene regulates the growth and development of both PR and LR under LN conditions, and confers a degree of resistance. These findings advance our understanding of RDGs in B. napus and provide valuable gene resources for subsequent molecular breeding.

Brassica napus L. is one of the most important oil crops in the world, and improving its nitrogen efficiency is a key strategy for enhancing low-nitrogen tolerance and increasing yield. Ammonium transporters (AMTs) play critical roles in NH₄⁺ transport in plants and significantly influence nitrogen use efficiency and yield. To identify promising candidate AMT genes for rapeseed improvement, this study systematically analyzed the evolution and expression of AMT genes across the Archaeplastida plants, especially in Brassica species of the U’s triangle. A total of 368 AMT genes were identified from 35 Archaeplastida species, including 180 AMT1 and 188 AMT2 homologs. Gene duplication analysis revealed that small-scale duplication (SSD) was the primary mechanism driving gene expansion from aquatic algae to angiosperms in both AMT1 and AMT2 families, which were under the influence of purifying selection. In the U’s triangle, allopolyploidization, particularly whole-genome duplication (WGD), was the primary mechanism for AMT expansion, accompanied by gene loss. Expression profiling indicated that most BnAMTs respond to hormonal and low-nitrogen signals and exhibit tissue-specific expression patterns. Notably, four candidate genes (BnAMT1;5, BnAMT1;12, BnAMT2;2, BnAMT2;4) exhibited high expression levels and responsiveness to low-nitrogen stress. Haplotype analysis further linked specific polymorphisms in BnAMT1;5 and BnAMT2;2 to variations in plant height and yield. Collectively, these findings elucidate the evolutionary processes and regulatory mechanisms of AMTs, laying a foundation for enhancing nitrogen utilization efficiency in B. napus and other crops.