Application of oxygen-sensing technology to measure seed quality of Ginkgo biloba

Germination tests are currently the most widely used method to evaluate seed quality of Ginkgo biloba L., but they are time-consuming and labor intensive. Oxygen-sensing technology, based on the principle of fluorescence quenching to detect oxygen and assess seed quality was used to rapidly evaluate seed quality of two varieties (Shandong Tancheng 202 and Zhejiang Dafoshou) of G. biloba from five mother plants. Fifteen samples of three vigor levels were produced by accelerated aging treatments. This process was applied in duplicate. A portable oxygen-sensing detector was employed to measure oxygen content during seed germination in a closed system at 25 A degrees C each day until day 14. Four oxygen metabolism indices were calculated: oxygen consumption index, oxygen consumption rate, critical oxygen concentration, and theoretical germination time (T (GT)). Additionally, we tested laboratory germination and field emergence. The results of a one-way analysis of variance and correlation analysis showed that T (GT) was the candidate index to evaluate seed quality of G. biloba. Therefore, the T (GT) value was used to validate the reliability of oxygen-sensing evaluation for Zhejiang Dafoshou seeds kept under four storage conditions. The trend in the change in oxygen metabolism agreed completely agreement with that of seed germination under all storage conditions. The oxygen-sensing test reliably and rapidly assessed seed quality of G. biloba. The germination rate of Zhejiang Dafoshou was accurately predicted by T (GT).

Spatiotemporal oxygen dynamics in young leaves reveal cyclic hypoxia in plants

Oxygen is essential for plant growth and development.Hypoxia occurs in plants due to limited oxygen avail-abilityfollowing adverse environmental conditions as well inhypoxic niches in otherwisenormoxic environ-ments.However,the existence and functional integration of spatiotemporal oxygen dynamics with plant development remains unknown.In animal systems dynamic fluctuations in oxygen availability are known as cyclic hypoxia.In this study,we demonstrate that cyclic fluctuations in internal oxygen levels occur in young emerging leaves of Arabidopsis plants.Cyclic hypoxia in plants is based on a mechanism requiring the ETHYLENE RESPONSE FACTORS type VII(ERFVII)that are central components of the oxygen-sensing machinery in plants.The ERFVll-dependent mechanism allows precise adjustment of leaf growth in response to carbon status and oxygen availability within plant cells.This study thus establishes a functional connection between internal spatiotemporal oxygen dynamics and developmental processes of plants.

Dual prognostic role of 2-oxoglutarate-dependent oxygenases in ten cancer types:implications for cell cycle regulation and cell adhesion maintenance

Background: Tumor hypoxia is associated with metastasis and resistance to chemotherapy and radiotherapy. Genes involved in oxygen-sensing are clinically relevant and have significant implications for prognosis. In this study, we examined the pan-cancer prognostic significance of oxygen-sensing genes from the 2-oxoglutarate-dependent oxygenase family. Methods: A multi-cohort, retrospective study of transcriptional profiles of 20,752 samples of 25 types of cancer was performed to identify pan-cancer prognostic signatures of 2-oxoglutarate-dependent oxygenase gene family (a family of oxygen-dependent enzymes consisting of 61 genes). We defined minimal prognostic gene sets using three independent pancreatic cancer cohorts (n = 681). We identified two signatures, each consisting of 5 genes. The ability of the signa-tures in predicting survival was tested using Cox regression and receiver operating characteristic (ROC) curve analyses. Results: Signature 1 (KDM8, KDM6B, P4HTM, ALKBH4, ALKBH7) and signature 2 (KDM3A, P4HA1, ASPH, PLOD1, PLOD2) were associated with good and poor prognosis. Signature 1 was prognostic in 8 cohorts representing 6 cancer types (n = 2627): bladder urothelial carcinoma (P = 0.039), renal papillary cell carcinoma (P = 0.013), liver cancer (P = 0.033 and P = 0.025), lung adenocarcinoma (P = 0.014), pancreatic adenocarcinoma (P < 0.001 and P = 0.040), and uterine corpus endometrial carcinoma (P < 0.001). Signature 2 was prognostic in 12 cohorts representing 9 cancer types (n = 4134): bladder urothelial carcinoma (P = 0.039), cervical squamous cell carcinoma and endocervical adenocar-cinoma (P = 0.035), head and neck squamous cell carcinoma (P = 0.038), renal clear cell carcinoma (P = 0.012), renal papillary cell carcinoma (P = 0.002), liver cancer (P < 0.001, P < 0.001), lung adenocarcinoma (P = 0.011), pancreatic adenocarcinoma (P = 0.002, P = 0.018, P < 0.001), and gastric adenocarcinoma (P = 0.004). Multivariate Cox regression confirmed independent clinical relevance of the signatures in these cancers. ROC curve analyses confirmed superior performance of the signatures to current tumor staging benchmarks. KDM8 was a potential tumor suppressor down- regulated in liver and pancreatic cancers and an independent prognostic factor. KDM8 expression was negatively correlated with that of cell cycle regulators. Low KDM8 expression in tumors was associated with loss of cell adhesion phenotype through HNF4A signaling. Conclusion: Two pan-cancer prognostic signatures of oxygen-sensing genes were identified. These genes can be used for risk stratification in ten diverse cancer types to reveal aggressive tumor subtypes.

The phosphorescence nanocomposite thin film with rich oxygen vacancy:Towards sensitive oxygen sensor

Organic room temperature phosphorescent(ORTP)materials provide an exciting research direction for phosphorescent oxygen(O_(2)) sensors due to their high sensitivity and rapid response to O_(2).However,most pure ORTP materials are tightly-packed aromatic compound crystals in a face-to-face manner,which largely prohibits effective O_(2) diffusion for sensing.Thus,how to solve this contradiction still faces huge challenges.Here,the use of organic phosphorescent indicator carbon dots(CDs),inorganic matrix layered double hydroxides(LDHs)and polymers(PVA)successfully prepared an ultra-long RTP composite film whose phosphorescence decay intensity is linearly related to O_(2) concentration.More importantly,the use of the abundant O_(2) defects(Vo)on the surface of the inorganic matrix LDHs to adsorb O_(2),which further accelerates the phosphorescence quenching of the thin film and improves the O_(2) response.This strategy will provide the possibility to develop high-sensitivity phosphorescent O_(2) sensors from a new perspective.