Color components determination and full-length comparative transcriptomic analyses reveal the potential mechanism of carotenoid synthesis during Paphiopedilum armeniacum flowering.

Background: Paphiopedilum armeniacum (P. armeniacum), an ornamental plant native to China, is known for its distinctive yellow blossoms. However, the mechanisms underlying P. armeniacum flower coloration remain unclear. Methods: We selected P. armeniacum samples from different flowering stages and conducted rigorous physicochemical analyses. The specimens were differentiated based on their chemical properties, specifically their solubilities in polar solvents. This key step enabled us to identify the main metabolite of flower color development of P. armeniacum, and to complete the identification by High-performance liquid chromatography (HPLC) based on the results. Additionally, we employed a combined approach, integrating both third-generation full-length transcriptome sequencing and second-generation high-throughput transcriptome sequencing, to comprehensively explore the molecular components involved. Results: We combined physical and chemical analysis with transcriptome sequencing to reveal that carotenoid is the main pigment of P. armeniacum flower color. Extraction colorimetric method and HPLC were used to explore the characteristics of carotenoid accumulation during flowering. We identified 28 differentially expressed carotenoid biosynthesis genes throughout the flowering process, validated their expression through fluorescence quantification, and discovered 19 potential positive regulators involved in carotenoid synthesis. Among these candidates, three RCP2 genes showed a strong potential for governing the PDS and ZDS gene families. In summary, our study elucidates the fundamental mechanisms governing carotenoid synthesis during P. armeniacum flowering, enhancing our understanding of this process and providing a foundation for future research on the molecular mechanisms driving P. armeniacum flowering.

Emergence of Corona Is Independent of the Four Whorls of Floral Organs in Narcissus tazetta.

Plants of the genus Narcissus are well-known for their characteristic corona morphology, which structural origins have been a bone of contention among scholars. With "Jinzhanyintai" (JZ) and "Yulinglong" (YLL)-two major close-originated cultivars of Chinese narcissus (Narcissus tazetta L. var. chinensis Roem)-as materials, anatomic observation was made on floral organs during corona morphogenesis by dissection with hands under a stereomicroscope, paraffin section, scanning electron microscopy, and high-resolution X-ray tomography. It was uncovered that corona primordia of both cultivars appeared following the end of the differentiation of other floral organs, with differentiation sites located at the inner wall of the juncture of the base of tepals and the upper margin of the hypanthium. Affected by staminal filaments, the corona primordia of JZ experienced a three-stage differentiation process, namely blockage from the second whorl of stamens, blockage from the first whorl of stamens, and healing of corona primordia. However, the expanded spatial structure of the first whorl of petal-like stamens blocked the path of differentiation of YLL corona primordia, giving rise to slow differentiation of the corona primordia at the base of the first whorl of petal-like stamens and malformed differentiation of the corona primordia in the interval between the two whorls of petal-like stamens. Thus, a fragmented structure consisting of typical and fragmented coronas was formed. Furthermore, petal-like stamens of YLL in the lower part had a corona-like morphology. The spatio-temporal specificity of corona differentiation convincingly demonstrates that the corona is a structure independent of and different from the typical four whorls of floral organs, but also highly correlated with stamen.

Identification and transcriptome data analysis of ARF family genes in five Orchidaceae species.

The Orchidaceae is a large family of perennial herbs especially noted for the exceptional diversity of specialized flowers. Elucidating the genetic regulation of flowering and seed development of orchids is an important research goal with potential utility in orchid breeding programs. Auxin Response Factor (ARF) genes encode auxin-responsive transcription factors, which are involved in the regulation of diverse morphogenetic processes, including flowering and seed development. However, limited information on the ARF gene family in the Orchidaceae is available. In this study, 112 ARF genes were identified in the genomes of 5 orchid species (Apostasia shenzhenica, Dendrobium catenatum, Phalaenopsis aphrodite, Phalaenopsis equestris and Vanilla planifolia,). These genes were grouped into 7 subfamilies based on their phylogenetic relationships. Compared with the ARF family in model plants, such as Arabidopsis thaliana and Oryza sativa, one group of ARF genes involved in pollen wall synthesis has been lost during evolution of the Orchidaceae. This loss corresponds with absence of the exine in the pollinia. Through mining of the published genomic and transcriptomic data for the 5 orchid species: the ARF genes of subfamily 4 may play an important role in flower formation and plant growth, whereas those of subfamily 3 are potentially involved in pollen wall development. the study results provide novel insights into the genetic regulation of unique morphogenetic phenomena of orchids, which lay a foundation for further analysis of the regulatory mechanisms and functions of sexual reproduction-related genes in orchids.

Effects of Different Temperature and Time Durations of Virus Inactivation on Results of Real-time Fluorescence PCR Testing of COVID-19 Viruses.

The novel Coronavirus SARS-CoV-2 caused an outbreak of pneumonia in Wuhan, Hubei province of China in January 2020. This study aims to investigate the effects of different temperature and time durations of virus inactivation on the results of PCR testing for SARS-CoV-2. Twelve patients at the Renmin Hospital of Wuhan University suspected of being infected with SARS-CoV-2 were selected on February 13, 2020 and throat swabs were taken. The swabs were stored at room temperature (20-25°C), then divided into aliquots and subjected to different temperature for different periods in order to inactivate the viruses (56°C for 30, 45, 60 min; 65, 70, 80°C for 10, 15, 20 min). Control aliquots were stored at room temperature for 60 min. Then all aliquots were tested in a real-time fluorescence PCR using primers against SARS-CoV-2. Regardless of inactivation temperature and time, 7 of 12 cases (58.3%) tested were positive for SARS-CoV-2 by PCR, and cycle threshold values were similar. These results suggest that virus inactivation parameters exert minimal influence on PCR test results. Inactivation at 65°C for 10 min may be sufficient to ensure safe, reliable testing.

Photostability study of cis-configuration neonicotinoid insecticide cycloxaprid in water.

Cycloxaprid (CYC) is a new cis-configuration neonicotinoid insecticide, which is currently under development in China for agricultural pest control. Considering the photodegradation of CYC is important for the application of CYC in the future, the photochemical behavior of CYC in aqueous solution was herein investigated in a "merry-go-round" reactor under a 300 W high-pressure mercury lamp. Twenty-five photodegradation products were identified via UPLC-TOF-ESI-MS/MS. The results suggested that NTN32692, the precursor of CYC was the predominant photodegradation product. CYC photodegrades via a more complex mechanism than imidacloprid and four potential photodegradation pathways were proposed.

Specific Synergist for Neonicotinoid Insecticides: IPPA08, a cis-Neonicotinoid Compound with a Unique Oxabridged Substructure.

Insecticide synergists are key components to increase the control efficacy and reduce active ingredient use. Here, we describe a novel insecticide synergist with activity specific for insecticidal neonicotinoids. The synergist IPPA08, a cis configuration neonicotinoid compound with a unique oxabridged substructure, could increase the toxicity of most neonicotinoid insecticides belonging to the Insecticide Resistance Action Committee (IRAC) 4A subgroup against a range of insect species, although IPPA08 itself was almost inactive to insects at synergistic concentrations. Unfortunately, similar effects were observed on the honey bee (Apis mellifera) and the brown planthopper (Nilaparvata lugens), resistant to imidacloprid. IPPA08 did not show any effects on toxicity of insecticides with different targets, which made us define it as a neonicotinoid-specific synergist. Unlike most insecticide synergists, by inhibition of activities of detoxification enzymes, IPPA08 showed no effects on enzyme activities. The results revealed that IPPA08 worked as a synergist through a distinct way. Although the modulating insect nicotinic acetylcholine receptors (nAChRs, targets of neonicotinoid insecticides) were supposed as a possible mode of action for IPPA08 as a neonicotinoid-specific synergist, direct evidence is needed in further studies. In insect pest control, IPPA08 acts as a target synergist to increase neonicotinoid toxicity and reduce the amount of neonicotinoid used. Combinations of IPPA08 and insecticidal neonicotinoids may be developed into new insecticide formulations. In summary, combining an active ingredient with a "custom" synergist appears to be a very promising approach for the development of effective new insecticide products.

[Aberrant Expression Notch1 and Asb2 mRNA in Bone Marrow from Patients with P210(+) Chronic Myeloid Leukemia].

OBJECTIVE: To explore the mRNA expression level of Notch1 and ASB2 in bone marrow mononuclear cells of patients with P210(+) chronic myeloid leukemia and the correlation between Notch signaling pathway and ubiquitination in chronic myeloid leukemia, so as to provide the valuable information for investigating the pathogenesis of chronic myeloid leukemia and clinical treatment. METHODS: Bone marrow was collected from 32 patients with newly diagnosed chronic myeloid leukemia and 34 non-hematopathic and healthy individuals (control group), respectively. The mRNA expression levels of Notch1 and ASB2 were detected by real-time quantitative PCR. RESULTS: The expression of Notch1 mRNA in CML patients were significantly different from that of healthy individuals group (t=36.3, P<0.01), which was 337.8 times of the healthy individuals. Moreover, the expression level of ASB2 mRNA in CML group was significantly higher than that in healthy individuals (t=19.4, P<0.01). The mRNA expression of Notch1 and ASB2 gene was positive correlation (r=0.504, P<0.01). CONCLUSION: The aberrant expression of Notch1 and Asb2 exists in patients with P210 positive CML, which may be involved in incidence and development of CML.

Synthesis and Nematicidal Activities of 1,2,3-Benzotriazin-4-one Derivatives against Meloidogyne incognita.

A series of novel 1,2,3-benzotriazin-4-one derivatives were synthesized by the reaction of 3-bromoalkyl-1,2,3-benzotriazin-4-ones with potassium salt of 2-cyanoimino-4-oxothiazolidine in the presence of potassium iodide. Nematicidal assays in vivo showed that some of them exhibited good control efficacy against the cucumber root-knot nematode disease caused by Meloidogyne incognita, up to 100% at the concentration of 10.0 mg L(-1), which indicated that 1,2,3-benzotriazin-4-one derivatives might be potential for novel promising nematicides. The nematicidal activity was influenced by the combination of substituent type, substituted position, and linker length in the molecule. The inhibition rate data at the concentrations of 5.0 and 1.0 mg L(-1) for the compounds with high inhibitory activities were also provided. When tested in vitro, none of them showed direct inhibition against M. incognita. The investigation of a significant difference between in vivo and in vitro data is in progress.