Plants require a flexible avoidance mechanism as they need to cope with external stimuli and challenges through complex specialized metabolites, among which volatile terpenoids make outstanding contributions, acting as key media signal substances in the cooperation between plants and surrounding organisms. In recent decades, the research on the identification and functional characterization of terpenoid synthase and factors regulating metabolic shunts has gained significant attention, leading to substantial progress and notable achievements. However, with the popularization of terpenoids in insect and disease prevention, medical care, cosmetics, and other fields, coupled with increasing resistance to artificially produced chemical products, the demand for natural terpenoids has outpaced supply, prompting the emergence and popularity of targeted engineering for the mass production of terpenoids using microorganisms and plants as platforms. In this paper, we provide a detailed overview of the key knowledge and research progress of volatile terpenoids with regard to multiple functions, complex synthetic pathways, key terpenoid synthase genes, related regulatory factors, and target engineering.

Clostridioides difficile infection (CDI) is a major healthcare-associated concern, particularly in the elderly. While CDI typically manifests as toxin-mediated colitis, hematogenous dissemination leading to bacteremia is relatively rare and associated with high mortality. We report an unusual case of C. difficile bacteremia in an octogenarian female patient occurring shortly after right hemicolectomy for ascending colon adenocarcinoma. This critically ill patient presented with bloodstream infection in the ICU following surgery. Multiple risk factors converged, including advanced age, extensive colorectal surgery with mucosal disruption, malignancy, and broad-spectrum antibiotic exposure. Blood culture identification required specific anaerobic processing. Combined intravenous and high-dose oral vancomycin therapy, guided by rapid microbiological confirmation, led to successful resolution of the bacteremia. This case underscores the potential for life-threatening C. difficile bacteremia in vulnerable elderly patients post-colorectal cancer surgery, highlights the diagnostic challenges (necessitating anaerobic blood cultures), and emphasizes the critical importance of early suspicion, aggressive multimodal therapy, and meticulous antimicrobial stewardship in this high-risk population. It serves as a crucial reminder of this devastating complication.

Digitalis purpurea, valued for its cardiotonic glycosides, remains an important medicinal species. Optimizing cultivation to enhance photosynthetic efficiency is critical for improving both biomass accumulation and metabolite yield. In this study, we compared the photosynthetic induction responses of D. purpurea from low light to high light with those of Cucumis sativus, a high-performance reference species, to identify key physiological constraints. Compared with Cucumis, D. purpurea exhibited lower net photosynthetic rate (A) and maximum carboxylation rates (V_cmax) under both induction and steady-state conditions (A_f and V_cmaxf). The time required to reach steady-state photosynthesis was substantially longer in D. purpurea, resulting in significantly lower cumulative carbon gain (20.6 vs. 28.8 mmol m⁻²) and a higher carbon loss ratio (10.7% vs. 6.8%). In addition, the averaged WUE_i during induction in D. purpurea was 20.4% lower than in Cucumis; this reduction was exacerbated by continued stomatal opening after photosynthesis stabilized, leading to further inefficiency in water use. Limitation analysis further revealed contrasting dominant constraints: biochemical limitation accounted for 88.8% of total limitation in Cucumis, whereas stomatal limitation predominated in D. purpurea (64.3%). Together, these results highlight stomatal regulation as the primary bottleneck during photosynthetic induction in D. purpurea, leading to transient carbon losses and reduced water-use efficiency, providing a physiological basis for targeted cultivation strategies to improve both productivity and cardiotonic glycoside yield.