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Floral flavonols play specific pivotal roles in pollinator attraction, pollen germination and fertility, in addition to other functions in vegetative organs. For many plants, the process of flavonol biosynthesis in late flower development stages and in mature flower tissues is poorly understood, in contrast to early flower development stages. It is thought that this process may be regulated independently of subgroup 7 R2R3 MYB (SG7 MYB) transcription factors. In this study, two FLS genes were shown to be expressed synchronously with the flower development-specific and tissue-specific biosynthesis of flavonols in Freesia hybrida. FhFLS1 contributed to flavonol biosynthesis in early flower buds, toruses and calyxes, and was regulated by four well-known SG7 MYB proteins, designated as FhMYBFs, with at least partial regulatory redundancy. FhFLS2 accounted for flavonols in late developed flowers and in the petals, stamens and pistils, and was targeted directly by non SG7 MYB protein FhMYB21L2. In parallel, AtMYB21 and AtMYB24 also activated AtFLS1, a gene highly expressed in Arabidopsis anthers and pollen, indicating the conserved regulatory roles of MYB21 against FLS genes in these two evolutionarily divergent angiosperm plants. Our results reveal a novel regulatory and synthetic mechanism underlying flavonol biosynthesis in floral organs and tissues which may be exploited to investigate supplementary roles of flavonols in flowers.

Inhibition of bacterial growth under aerobic conditions by elevated levels of cyclic adenosine 3′,5′-monophosphate (cAMP), first revealed more than 50 years ago, was attributed to accumulation of toxic methylglyoxal (MG). Here, we report a Crp-dependent mechanism rather than MG accumulation that accounts for the phenotype in Shewanella oneidensis, an emerging research model for the bacterial physiology. We show that a similar phenotype can be obtained by removing CpdA, a cAMP phosphodiesterase that appears more effective than its Escherichia coli counterpart. Although production of heme c and cytochromes c is correlated well with cAMP levels, neither is sufficient for the retarded growth. Quantities of overall cytochromes c increased substantially in the presence of elevated cAMP, a phenomenon resembling cells respiring on non-oxygen electron acceptors. In contrast, transcription of Crp-dependent genes encoding both cytochromes bd and cbb3 oxidases is substantially repressed under the same condition. Overall, our results suggest that cAMP of elevated levels drives cells into a low-energetic status, under which aerobic respiration is inhibited.

To assess the prevalence and causes of low vision and blindness in type 2 diabetes patients, a population-based cross-sectional study including 8952 rural-dwelling residents aged 40 years or older from Hengli Town in Southern China was conducted. Participants underwent standard interviews, physical measurements, laboratory tests, and comprehensive eye examinations. Low vision and blindness were defined based on WHO criteria. Visual acuity data were available for 1348 (89.9%) of the 1500 subjects with type 2 diabetes. Age-standardized prevalence of bilateral low vision and blindness assessed in the better-seeing eye was 2.9% (95% confidence interval [CI]: 2.0–3.8) and 0.7% (95% CI: 0.2–1.1) based on best-corrected visual acuity (BCVA). Cataracts were the primary cause of low vision and blindness. Visual impairment was associated with age (odds ratio [OR]: 3.73, 95% CI: 2.39–5.83), education level (OR: 3.21, 95% CI: 1.63–6.29), duration of diabetes (OR: 1.14, 95% CI: 1.04–1.25) and body mass index (OR: 0.86, 95% CI: 0.77–0.95). Our data suggest that approximately 70% of visual impairment in this diabetic population could be eliminated with appropriate cataract surgery or spectacle correction. Greater consideration should be given to older type 2 diabetes patients with a level of lower education.

Purpose: To depict the normal anatomy of cranial nerves in detail and define the exact relationships between cranial nerves and adjacent structures with three-dimensional reversed fast imaging with steady-state precession (FISP) (3D-PSIF) with diffusion-weighted MR sequence. Materials and Methods:3D-PSIF with diffusion-weighted MR sequence was performed and axial images were obtained in 22 healthy volunteers. Postprocessing techniques were used to generate images of cranial nerves, and the images acquired were compared with anatomical sections and textbook diagrams. Results:In all subjects, 3D-PISF sequence could produce homogeneous images and high contrast between the cranial nerves and other solid structures. The intracranial portions of all cranial nerves except the olfactory nerve were identified; the extracranial portions of nerves II-XII, except the nerves within the cavernous sinuses, were identified in all subjects bilaterally. Conclusion:The 3D-PSIF with diffusion-weighted sequence can characterize the normal MR appearance of cranial nerves and its branches. The ability to define the nerves may provide greater sensitivity and specificity in detecting abnormalities of craniofacial structure. THREE-DIMENSIONAL (3D) high-resolution MRI has been used to evaluate the cranial nerves. Detection of abnormalities such as perineural tumors spread requires detailed knowledge of the normal MR appearance of the cranial nerves and surrounding structures. The cranial nerves originate in the brain, leave its surface, and pass through certain foramina or fissures of the skull to be distributed in and about the head and neck. In addition, the vagus nerve continues into the thorax and abdomen to innervate some of the viscera (1). Imaging cranial nerves is a big challenge due to their fine structure and complex anatomy. With recent improvements in MRI, especially 3.0-T MRI, improved imaging, which allows 3D high-resolution views of fine structures, plays a pivotal role in successful diagnosis and treatment of lesions in the head and neck area. The purpose of this study was to visualize and portray the normal anatomy of cranial nerves in detail and define the exact relationships between cranial nerves and adjacent structures using a high-resolution imaging technique of 3D reversed fast imaging with steady-state precession (FISP) (3D-PSIF) with diffusion-weighted MR sequence (PSIF is a reversal of the acronym FISP). MATERIALS AND METHODS SubjectsMRI examinations were performed in 22 volunteers (13 men and 9 women; age range, 16 -57 years, mean: 37.4 years). All 22 volunteers had no neurological symptoms or neurological diseases. The review board of our department approved our study, and written informed consent was obtained from all subjects. MRI TechniqueMRI was performed with a clinical 3.0-T MRI system ( Magnetom Trio with TIM system; Siemens, Erlangen, Germany) using a standard head and neck coil. After conventional T1-and T2-weighted spin-echo (SE) imaging was completed, the 3D-PSIF with diffusionweighted sequence was p...

Nitrite has been used as a bacteriostatic agent for centuries in food preservation. It is widely accepted that this biologically inert molecule functions indirectly, serving as a stable reservoir of bioactive nitric oxide (NO) and other reactive nitrogen species to impact physiology. As a result, to date, we know surprisingly little about targets of nitrite. Here, we carry out comparative analyses of nitrite and NO physiology in and in , a Gram-negative environmental bacterium renowned for respiratory versatility. These two bacteria differ from each other in many aspects of nitrite and NO physiology, including NO generation, NO degradation, and unexpectedly, their contrary susceptibility to nitrite and NO. In cell extracts of both bacteria, most of the NO targets are also susceptible to nitrite, and vice versa. However, with respect to growth inhibition caused by NO, the targets are impacted distinctly; NO targets are responsible for the inhibition of growth of but not of More surprisingly, all proteins identified to be implicated in NO tolerance in other bacteria appear to play a dispensable role in protecting against NO. These data suggest that is equipped with a robust but yet unknown NO protecting system. In the case of nitrite, it is clear that the target of physiological significance in both bacteria is cytochrome heme-copper oxidase. Nitrite is toxic to living organisms at high levels, but such antibacterial effects of nitrite are attributable to the formation of nitric oxide (NO), a highly reactive radical gas molecule. Here, we report that is highly resistant to NO but sensitive to nitrite compared to by approximately 4-fold. In both bacteria, nitrite inhibits bacterial growth by targeting cytochrome heme-copper oxidase. In contrast, the targets of NO are diverse. Although these targets are similar in and, they are responsible for growth inhibition caused by NO in the former but not in the latter. Overall, the presented data, along with the previous data, solidify a proposal that the targets of NO and nitrite in bacteria are largely different.