Background: Anthocyanins are common substances with many agro-food industrial applications. However, anthocyanins are generally considered to be found only in natural plants. Our previous study isolated and purified the fungus Aspergillus sydowii H-1, which can produce purple pigments during fermentation. To understand the characteristics of this strain, a transcriptomic and metabolomic comparative analysis was performed with A. sydowii H-1 from the second and eighth days of fermentation, which confer different pigment production. Results: We found five anthocyanins with remarkably different production in A. sydowii H-1 on the eighth day of fermentation compared to the second day of fermentation. LC-MS/MS combined with other characteristics of anthocyanins suggested that the purple pigment contained anthocyanins. A total of 28 transcripts related to the anthocyanin biosynthesis pathway was identified in A. sydowii H-1, and almost all of the identified genes displayed high correlations with the metabolome. Among them, the chalcone synthase gene (CHS) and cinnamate-4-hydroxylase gene (C4H) were only found using the de novo assembly method. Interestingly, the best hits of these two genes belonged to plant species. Finally, we also identified 530 lncRNAs in our datasets, and among them, three lncRNAs targeted the genes related to anthocyanin biosynthesis via cis-regulation, which provided clues for understanding the underlying mechanism of anthocyanin production in fungi. Conclusion: We first reported that anthocyanin can be produced in fungus, A. sydowii H-1. Totally, 31 candidate transcripts were identified involved in anthocyanin biosynthesis, in which CHS and C4H, known as the key genes in anthocyanin biosynthesis, were only found in strain H1, which indicated that these two genes may contribute to anthocyanins producing in H-1. This discovery expanded our knowledges of the biosynthesis of anthocyanins and provided a direction for the production of anthocyanin.

Background: Global public health is seriously threatened by the escalating issue of antimicrobial resistance (AMR). Antimicrobial peptides (AMPs), pivotal components of the innate immune system, have emerged as a potent solution to AMR due to their therapeutic potential. Employing computational methodologies for the prompt recognition of these antimicrobial peptides indeed unlocks fresh perspectives, thereby potentially revolutionizing antimicrobial drug development. Methods: In this study, we have developed a model named as deepAMPNet. This model, which leverages graph neural networks, excels at the swift identification of AMPs. It employs structures of antimicrobial peptides predicted by AlphaFold2, encodes residue-level features through a bi-directional long short-term memory (Bi-LSTM) protein language model, and constructs adjacency matrices anchored on amino acids’ contact maps. Results: In a comparative study with other state-of-the-art AMP predictors on two external independent test datasets, deepAMPNet outperformed in accuracy. Furthermore, in terms of commonly accepted evaluation matrices such as AUC, Mcc, sensitivity, and specificity, deepAMPNet achieved the highest or highly comparable performances against other predictors. Conclusion: deepAMPNet interweaves both structural and sequence information of AMPs, stands as a high-performance identification model that propels the evolution and design in antimicrobial peptide pharmaceuticals. The data and code utilized in this study can be accessed at https://github.com/Iseeu233/deepAMPNet.

Light-harvesting chlorophyll a/b-binding (LHC) superfamily proteins play a vital role in photosynthesis. Although the physiological and biochemical functions of LHC genes have been well-characterized, the structural evolution and functional differentiation of the products need to be further studied. In this paper, we report the genome-wide identification and phylogenetic analysis of LHC genes in photosynthetic organisms. A total of 1222 non-redundant members of the LHC family were identified from 42 species. According to the phylogenetic clustering of their homologues with Arabidopsis thaliana, they can be divided into four subfamilies. In the subsequent evolution of land plants, a whole-genome replication (WGD) event was the driving force for the evolution and expansion of the LHC superfamily, with its copy numbers rapidly increasing in angiosperms. The selection pressure of photosystem II sub-unit S (PsbS) and ferrochelatase (FCII) families were higher than other subfamilies. In addition, the transcriptional expression profiles of LHC gene family members in different tissues and their expression patterns under exogenous abiotic stress conditions significantly differed, and the LHC genes are highly expressed in mature leaves, which is consistent with the conclusion that LHC is mainly involved in the capture and transmission of light energy in photosynthesis. According to the expression pattern and copy number of LHC genes in land plants, we propose different evolutionary trajectories in this gene family. This study provides a basis for understanding the molecular evolutionary characteristics and evolution patterns of plant LHCs.

Prodigiosin is an important secondary metabolite produced by Serratia marcescens. It can help strains resist stresses from other microorganisms and environmental factors to achieve self-preservation. Prodigiosin is also a promising secondary metabolite due to its pharmacological characteristics. However, pigmentless S. marcescens mutants always emerge after prolonged starvation, which might be a way for the bacteria to adapt to starvation conditions, but it could be a major problem in the industrial application of S. marcescens. To identify the molecular mechanisms of loss of prodigiosin production, two mutants were isolated after 16 days of prolonged incubation of wild-type (WT) S. marcescens 1912768R; one mutant (named 1912768WR) exhibited reduced production of prodigiosin, and a second mutant (named 1912768W) was totally defective. Comparative genomic analysis revealed that the two mutants had either mutations or deletions in rpoS. Knockout of rpoS in S. marcescens 1912768R had pleiotropic effects. Complementation of rpoS in the ΔrpoS mutant further confirmed that RpoS was a positive regulator of prodigiosin production and that its regulatory role in prodigiosin biosynthesis was opposite that in Serratia sp. ATCC 39006, which had a different type of pig cluster; further, rpoS from Serratia sp. ATCC 39006 and other strains complemented the prodigiosin defect of the ΔrpoS mutant, suggesting that the pig promoters are more important than the genes in the regulation of prodigiosin production. Deletion of rpoS strongly impaired the resistance of S. marcescens to stresses but increased membrane permeability for nutritional competence; competition assays in rich and minimum media showed that the ΔrpoS mutant outcompeted its isogenic WT strain. All these data support the idea that RpoS is pleiotropic and that the loss of prodigiosin biosynthesis in S. marcescens 1912768R during prolonged incubation is due to a mutation in rpoS, which appears to be a self-preservation and nutritional competence (SPANC) trade-off.

The CCT (CO, COL and TOC1) gene family has been elucidated to be involved in the functional differentiation of the products in various plant species, but their specific mechanisms are poorly understood. In the present investigation, we conducted a genome-wide identification and phylogenetic analysis of CCT genes from microalgae to legumes. A total of 700 non-redundant members of the CCT gene family from 30 species were identified through a homology search. Phylogenetic clustering with Arabidopsis and domain conservation analysis categorized the CCT genes into three families. Multiple sequence alignment showed that the CCT domain contains important amino acid residues, and each CCT protein contains 24 conserved motifs, as demonstrated by the motif analysis. Whole-genome/segment duplication, as well as tandem duplication, are considered to be the driving forces in the evolutionary trajectory of plant species. This comprehensive investigation into the proliferation of the CCT gene family unveils the evolutionary dynamics whereby WGD/segment duplication is the predominant mechanism contributing to the expansion of the CCT genes. Meanwhile, the examination of the gene expression patterns revealed that the expression patterns of CCT genes vary in different tissues and at different developmental stages of plants, with high expression in leaves, which is consistent with the molecular regulation of flowering in photosynthesis by CCT. Based on the protein–protein interaction analysis of CCT genes in model plants, we propose that the CCT gene family synergistically regulates plant development and flowering with light-signaling factors (PHYs and PIFs) and MYB family transcription factors. Understanding the CCT gene family’s molecular evolution enables targeted gene manipulation for enhanced plant traits, including optimized flowering and stress resistance.