Aging is an inevitable physiological process, but delaying aging has always been an enduring human pursuit. Silibinin (SIL), derived from the seeds of the milk thistle plant, exhibits a broad spectrum of pharmacological properties, including anti-tumor effects, liver protection, inhibition of apoptosis, and alleviation of inflammation. However, whether it has anti-aging effects remains unclear. The SIL dietary supplement to Drosophila melanogaster prolonged lifespan, improved climbing ability, ameliorated age-associated intestinal barrier disruption, enhanced the resistance to oxidative stress, and increased the enzyme activities of superoxide dismutase (SOD) and catalase (CAT). Furthermore, RNA-seq results showed that SIL addition significantly upregulated 74 genes and downregulated 50 genes compared with the control. KEGG (Kyoto Encyclopedia of genes and genomes) analysis demonstrated that these differentially expressed genes were primarily involved in the Toll signaling pathway and endoplasmic reticulum proteins processing, six among which, including IM2, IM3, Drsl3, CG7556, GCS1, and TRAM, were particularly involved in the regulation by SIL supplementation. The results indicate that SIL exhibits anti-aging effects by enhancing antioxidant capacity and regulating aging-related signaling pathways. Therefore, SIL shows a potential application in anti-aging dietary regimens.

Pteroceltis tatarinowii Maxim is a famous paper-making tree endemic to China with a wide distribution. Leaves of this tree growing in different habitats show a certain plasticity, which is important for their ecological adaption. Here, the photosynthesis ability, hydraulic properties, and anatomy of P. tatarinowii leaves from a limestone forest (Langya Mountain) and a cultivated forest (Xiaoling Village) in Anhui province were compared. The results showed that leaves from Xiaoling Village had higher net photosynthesis rate and hydraulic conductivity, which were closely related to their higher vein density, stomatal density and palisade tissue thickness than leaves from Langya Mountain. However, lower leaf water potentials at turgor loss point and at 50% loss of conductivity, as well as a higher leaf hardness, for Langya Mountain leaves indicated their higher hydraulic safety and drought resistance than those of leaves from Xiaoling Village. This study reveals a hydraulic trade-off between efficiency and safety for P. tatarinowii leaves growing in distinct habitats. Further studies should include more habitats and different vegetation communities to clarify the ecological adaption so as to provide a scientific basis for the protection of this species.

UCYN‐A is a phenomenal diazotrophic cyanobacterium with significant ecological importance. UCYN‐A1 and UCYN‐A2 are the two most abundant ecotypes. Recently, the striking discovery of nitroplast, a novel N ₂ ‐fixing organelle in cultured B. bigelowii /UCYN‐A2 endosymbiont, indicated the possibility that UCYN‐A2 has evolved beyond endosymbiosis to an early phase of organellogenesis. This study addresses the following critical question: What evolutionary heterogeneity has emerged between UCYN‐A1 and UCYN‐A2? To investigate this issue, we comprehensively compared a total of seven genomes from UCYN‐A2 and UCYN‐A1. Under similar genome organizations, GC content, and gene composition, we still detected abundant genetic differences, including group–unique orthogroups, ANI below 85%, and 577 UCYN‐A2‐unique INDELs in single‐copy orthologous genes (SCOGs). Moreover, we also focused on the orthologous genes of 40 metabolic‐pathway genes in nitroplast. In addition to high‐informative SNPs and INDELs possessing distinct interlineage differences, we traced abundant codon usage “signatures” that serve as lineage‐unique molecular markers. Most notably, we successfully established a strain‐level identification map for UCYN‐A strains using codon aversion motifs, which represents the first case study of this approach in bacteria. In summary, all the comparative results reported here collectively indicate that UCYN‐A1 and UCYN‐A2 have evolved remarkable genomic heterogeneities. Furthermore, the findings of this work will definitely promote our current understanding of codon aversion and the evolution of UCYN‐A.