Umami is an important widely-used taste component of food seasoning. Umami peptides are specific structural peptides endowing foods with a favorable umami taste. Laboratory approaches used to identify umami peptides are time-consuming and labor-intensive, which are not feasible for rapid screening. Here, we developed a novel peptide sequence-based umami peptide predictor, namely iUP-BERT, which was based on the deep learning pretrained neural network feature extraction method. After optimization, a single deep representation learning feature encoding method (BERT: bidirectional encoder representations from transformer) in conjugation with the synthetic minority over-sampling technique (SMOTE) and support vector machine (SVM) methods was adopted for model creation to generate predicted probabilistic scores of potential umami peptides. Further extensive empirical experiments on cross-validation and an independent test showed that iUP-BERT outperformed the existing methods with improvements, highlighting its effectiveness and robustness. Finally, an open-access iUP-BERT web server was built. To our knowledge, this is the first efficient sequence-based umami predictor created based on a single deep-learning pretrained neural network feature extraction method. By predicting umami peptides, iUP-BERT can help in further research to improve the palatability of dietary supplements in the future.
Heterotrimeric guanine-nucleotide-binding proteins (G-proteins) play key roles in responses to various abiotic stress responses and tolerance in plants. However, the detailed mechanisms behind these roles remain unclear. Mulberry (Morus alba L.) can adapt to adverse abiotic stress conditions; however, little is known regarding the associated molecular mechanisms. In this study, mulberry G-protein genes, MaGα, MaGβ, MaGγ1, and MaGγ2, were independently transformed into tobacco, and the transgenic plants were used for resistance identification experiments. The ectopic expression of MaGα in tobacco decreased the tolerance to drought and salt stresses, while the overexpression of MaGβ, MaGγ1, and MaGγ2 increased the tolerance. Further analysis showed that mulberry G-proteins may regulate drought and salt tolerances by modulating reactive oxygen species’ detoxification. This study revealed the roles of each mulberry G-protein subunit in abiotic stress tolerance and advances our knowledge of the molecular mechanisms underlying G-proteins’ regulation of plant abiotic stress tolerance.
Tartary buckwheat microgreens (TBM) are popular worldwide products but display an extremely short shelf life. Thus, the effects of storage temperature, packaging material, and wash treatment on the quality and shelf life were analyzed. Headspace composition, weight loss, electrolyte leakage, microbial population and sensory quality were investigated during storage. Results showed that shelf life and quality of TBM decreased with the increment of storage temperature when stored at 5–25 °C. During 5 °C storage, LDPE bags were the best packaging materials for preserving the quality of LDPE, PE and HDPE bags. On the basis of 5 °C and LDPE packages, ClO2 + citric acid wash treatment could further inhibit quality deterioration and extend the shelf life. The results demonstrated bioactive constituents and antioxidant capacity were significantly affected by storage time. The study provides insights into developing optimal packaging and storage conditions for TBM.
Multiple plant lineages have independently evolved sex chromosomes and variable karyotypes to maintain their sessile lifestyles through constant biological innovation. Morus notabilis, a dioecious mulberry species, has the fewest chromosomes among Morus spp., but the genetic basis of sex determination and karyotype evolution in this species has not been identified. In this study, three high-quality genome assemblies were generated for Morus spp. [including dioecious M. notabilis (male and female) and Morus yunnanensis (female)] with genome sizes of 301–329 Mb and were grouped into six pseudochromosomes. Using a combination of genomic approaches, we found that the putative ancestral karyotype of Morus species was close to 14 protochromosomes, and that several chromosome fusion events resulted in descending dysploidy (2n = 2x = 12). We also characterized a ∼ 6.2-Mb sex-determining region on chromosome 3. Four potential male-specific genes, a partially duplicated DNA helicase gene (named MSDH) and three Ty3_Gypsy long terminal repeat retrotransposons (named MSTG1/2/3), were identified in the Y-linked area and considered to be strong candidate genes for sex determination or differentiation. Population genomic analysis showed that Guangdong accessions in China were genetically similar to Japanese accessions of mulberry. In addition, genomic areas containing selective sweeps that distinguish domesticated mulberry from wild populations in terms of flowering and disease resistance were identified. Our study provides an important genetic resource for sex identification research and molecular breeding in mulberry.