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Frontiers in Plant Science 2021Peel color is an important factor affecting commodity quality in vegetables; however, the genes controlling this trait remain unclear in wax gourd. Here, we used two F...
Peel color is an important factor affecting commodity quality in vegetables; however, the genes controlling this trait remain unclear in wax gourd. Here, we used two F genetic segregation populations to explore the inheritance patterns and to clone the genes associated with green and white skin in wax gourd. The F and BC trait segregation ratios were 3:1 and 1:1, respectively, and the trait was controlled by nuclear genes. Bulked segregant analysis of both F plants revealed peaks on Chr5 exceeding the confidence interval. Additionally, 6,244 F plants were used to compress the candidate interval into a region of 179 Kb; one candidate gene, (), encoding two-component response regulator-like protein pseudo-response regulator2 (APRR2), which is involved in the regulation of peel color, was present in this interval. Two bases (GA) present in the coding sequence of in green-skinned wax gourd were absent from white-skinned wax gourd. The latter contained a frameshift mutation, a premature stop codon, and lacked 335 residues required for the protein functional region. The chlorophyll content and expression were significantly higher in green-skinned than in white-skinned wax gourd. Thus, may regulate the peel color of wax gourd. This study provides a theoretical foundation for further studies of the mechanism of gene regulation for the fruit peel color of wax gourd.
PubMed: 34659288
DOI: 10.3389/fpls.2021.716772 -
Clinical Case Reports Aug 2021Antiangiogenic agents can induce a distinct MRI pattern in glioblastoma, characterized by a decrease in the contrast enhancement on T1-weighted images and a simultaneous...
Antiangiogenic agents can induce a distinct MRI pattern in glioblastoma, characterized by a decrease in the contrast enhancement on T1-weighted images and a simultaneous hyperintensity on T2-weighted or fluid-attenuated inversion recovery images.
PubMed: 34457284
DOI: 10.1002/ccr3.4604 -
Frontiers in Plant Science 2021Photoperiod-regulated floral transition is vital to the flowering plant. "Xiangfei" is a flowering ornamental plant with high development potential economically and is...
Photoperiod-regulated floral transition is vital to the flowering plant. "Xiangfei" is a flowering ornamental plant with high development potential economically and is a short-day woody perennial. However, the genetic regulation of short-day-induced floral transition in is unclear. To systematically research the responses of during this process, dynamic changes in morphology, physiology, and transcript levels were observed and identified in different developmental stages of long-day- and short-day-treated plants. We found that floral transition in occurred 10 d after short-day induction, but flower bud differentiation did not occur at any stage under long-day conditions. A total of 1,226 differentially expressed genes were identified, of which 146 genes were associated with flowering pathways of sugar, phytohormones, photoperiod, ambient temperature, and aging signals, as well as floral integrator and meristem identity genes. The trehalose-6-phosphate signal positively modulated floral transition by interacting with SQUAMOSA PROMOTER-BINDING-LIKE PROTEIN 4 (SPL4) in the aging pathway. Endogenous gibberellin, abscisic acid, cytokinin, and jasmonic acid promoted floral transition, whereas strigolactone inhibited it. In the photoperiod pathway, FD, CONSTANS-LIKE 12, and nuclear factors Y positively controlled floral transition, whereas PSEUDO-RESPONSE REGULATOR 7, FLAVIN-BINDING KELCH REPEAT F-BOX PROTEIN 1, and LUX negatively regulated it. SPL4 and pEARLI1 positively affected floral transition. Suppressor of Overexpression of Constans 1 and AGAMOUSLIKE24 integrated multiple flowering signals to modulate the expression of /, , , , , and , thereby regulating floral transition. Finally, we propose a regulatory network model for short-day-induced floral transition in . This study improves our understanding of flowering time regulation in and provides knowledge for its production and commercialization.
PubMed: 34456954
DOI: 10.3389/fpls.2021.715683 -
Neuro-oncology Advances 2021Currently, bevacizumab (BEV), an antiangiogenic agent, is used as an adjunctive therapy to re-irradiation and surgery in patients with recurrent high-grade gliomas... (Review)
Review
BACKGROUND
Currently, bevacizumab (BEV), an antiangiogenic agent, is used as an adjunctive therapy to re-irradiation and surgery in patients with recurrent high-grade gliomas (rHGG). BEV has shown to decrease enhancement on MRI, but it is often unclear if these changes are due to tumor response to BEV or treatment-induced changes in the blood brain barrier. Preliminary studies show that amino acid PET can aid in distinguishing these changes on MRI.
METHODS
The authors performed a systematic review of PubMed and Embase through July 2020 with the search terms 'bevacizumab' or 'Avastin' and 'recurrent glioma' and 'PET,' yielding 38 papers, with 14 meeting inclusion criteria.
RESULTS
Thirteen out of fourteen studies included in this review used static PET and three studies used dynamic PET to evaluate the use of BEV in rHGG. Six studies used the amino acid tracer [18F]FET, four studies used [11C]MET, and four studies used [18F]FDOPA.
CONCLUSION
[18F]FET, [11C]MET, and [18F]FDOPA PET in combination with MRI have shown promising results for improving accuracy in diagnosing tumor recurrence, detecting early treatment failure, and distinguishing between tumor progression and treatment-induced changes in patients with rHGG treated with BEV.
PubMed: 34409294
DOI: 10.1093/noajnl/vdab003 -
The Plant Cell Aug 2021The core plant circadian oscillator is composed of multiple interlocked transcriptional-translational feedback loops, which synchronize endogenous diel physiological...
The core plant circadian oscillator is composed of multiple interlocked transcriptional-translational feedback loops, which synchronize endogenous diel physiological rhythms to the cyclic changes of environmental cues. PSEUDO-RESPONSE REGULATORS (PRRs) have been identified as negative components in the circadian clock, though their underlying molecular mechanisms remain largely unknown. Here, we found that a subfamily of zinc finger transcription factors, B-box (BBX)-containing proteins, have a critical role in fine-tuning circadian rhythm. We demonstrated that overexpressing Arabidopsis thaliana BBX19 and BBX18 significantly lengthened the circadian period, while the null mutation of BBX19 accelerated the circadian speed. Moreover, BBX19 and BBX18, which are expressed during the day, physically interacted with PRR9, PRR7, and PRR5 in the nucleus in precise temporal ordering from dawn to dusk, consistent with the respective protein accumulation pattern of PRRs. Our transcriptomic and genetic analysis indicated that BBX19 and PRR9, PRR7, and PRR5 cooperatively inhibited the expression of morning-phased clock genes. PRR proteins affected BBX19 recruitment to the CCA1, LHY, and RVE8 promoters. Collectively, our findings show that BBX19 interacts with PRRs to orchestrate circadian rhythms, and suggest the indispensable role of transcriptional regulators in fine-tuning the circadian clock.
Topics: Arabidopsis; Arabidopsis Proteins; Circadian Rhythm; DNA-Binding Proteins; Gene Expression Regulation, Plant; Mutation; Phylogeny; Plants, Genetically Modified; Promoter Regions, Genetic; Repressor Proteins; Transcription Factors
PubMed: 34164694
DOI: 10.1093/plcell/koab133 -
The Plant Cell Sep 2021Seed germination and postgerminative growth require the precise coordination of multiple intrinsic and environmental signals. The phytohormone abscisic acid (ABA)...
Seed germination and postgerminative growth require the precise coordination of multiple intrinsic and environmental signals. The phytohormone abscisic acid (ABA) suppresses these processes in Arabidopsis thaliana and the circadian clock contributes to the regulation of ABA signaling. However, the molecular mechanism underlying circadian clock-mediated ABA signaling remains largely unknown. Here, we found that the core circadian clock proteins PSEUDO-RESPONSE REGULATOR5 (PRR5) and PRR7 physically associate with ABSCISIC ACID-INSENSITIVE5 (ABI5), a crucial transcription factor of ABA signaling. PRR5 and PRR7 positively modulate ABA signaling redundantly during seed germination. Disrupting PRR5 and PRR7 simultaneously rendered germinating seeds hyposensitive to ABA, whereas the overexpression of PRR5 enhanced ABA signaling to inhibit seed germination. Consistent with this, the expression of several ABA-responsive genes is upregulated by PRR proteins. Genetic analysis demonstrated that PRR5 promotes ABA signaling mainly dependently on ABI5. Further mechanistic investigation revealed that PRR5 stimulates the transcriptional function of ABI5 without affecting its stability. Collectively, our results indicate that these PRR proteins function synergistically with ABI5 to activate ABA responses during seed germination, thus providing a mechanistic understanding of how ABA signaling and the circadian clock are directly integrated through a transcriptional complex involving ABI5 and central circadian clock components.
Topics: Abscisic Acid; Arabidopsis; Arabidopsis Proteins; Basic-Leucine Zipper Transcription Factors; Germination; Repressor Proteins; Seeds; Signal Transduction; Transcription Factors
PubMed: 34152411
DOI: 10.1093/plcell/koab168 -
Horticulture Research May 2021Osmanthus fragrans is a well-known ornamental plant that has been domesticated in China for 2500 years. More than 160 cultivars have been found during this long period...
Osmanthus fragrans is a well-known ornamental plant that has been domesticated in China for 2500 years. More than 160 cultivars have been found during this long period of domestication, and they have subsequently been divided into four cultivar groups, including the Yingui, Jingui, Dangui, and Sijigui groups. These groups provide a set of materials to study genetic evolution and variability. Here, we constructed a reference genome of O. fragrans 'Liuyejingui' in the Jingui group and investigated its floral color traits and domestication history by resequencing a total of 122 samples, including 119 O. fragrans accessions and three other Osmanthus species, at an average sequencing depth of 15×. The population structure analysis showed that these 119 accessions formed an apparent regional cluster. The results of linkage disequilibrium (LD) decay analysis suggested that varieties with orange/red flower color in the Dangui group had undergone more artificial directional selection; these varieties had the highest LD values among the four groups, followed by the Sijigui, Jingui, and Yingui groups. Through a genome-wide association study, we further identified significant quantitative trait loci and genomic regions containing several genes, such as ethylene-responsive transcription factor 2 and Arabidopsis pseudoresponse regulator 2, that are positively associated with petal color. Moreover, we found a frameshift mutation with a 34-bp deletion in the first coding region of the carotenoid cleavage dioxygenase 4 gene. This frameshift mutation existed in at least one site on both alleles in all varieties of the Dangui group. The results from this study shed light on the genetic basis of domestication in woody plants, such as O. fragrans.
PubMed: 33931610
DOI: 10.1038/s41438-021-00531-0 -
The Plant Journal : For Cell and... Jun 2021Phytoene synthase (PSY1), capsanthin-capsorubin synthase (CCS), and pseudo-response regulator 2 (PRR2) are three major genes controlling fruit color in pepper (Capsicum...
Phytoene synthase (PSY1), capsanthin-capsorubin synthase (CCS), and pseudo-response regulator 2 (PRR2) are three major genes controlling fruit color in pepper (Capsicum spp.). However, the diversity of fruit color in pepper cannot be completely explained by these three genes. Here, we used an F population derived from Capsicum annuum 'SNU-mini Orange' (SO) and C. annuum 'SNU-mini Yellow' (SY), both harboring functional PSY1 and mutated CCS, and observed that yellow color was dominant over orange color. We performed genotyping-by-sequencing and mapped the genetic locus to a 6.8-Mb region on chromosome 2, which we named CaOr. We discovered a splicing mutation in the zeaxanthin epoxidase (ZEP) gene within this region leading to a premature stop codon. HPLC analysis showed that SO contained higher amounts of zeaxanthin and total carotenoids in mature fruits than SY. A color complementation assay using Escherichia coli harboring carotenoid biosynthetic genes showed that the mutant ZEP protein had reduced enzymatic activity. Transmission electron microscopy of plastids revealed that the ZEP mutation affected plastid development with more rod-shaped inner membrane structures in chromoplasts of mature SO fruits. To validate the role of ZEP in fruit color formation, we performed virus-induced gene silencing of ZEP in the yellow-fruit cultivar C. annuum 'Micropep Yellow' (MY). The silencing of ZEP caused significant changes in the ratios of zeaxanthin to its downstream products and increased total carotenoid contents. Thus, we conclude that the ZEP genotype can determine orange or yellow mature fruit color in pepper.
Topics: Capsicum; Carotenoids; Fruit; Gene Expression Regulation, Plant; Oxidoreductases; Pigmentation; Plant Proteins; Polymorphism, Single Nucleotide
PubMed: 33825226
DOI: 10.1111/tpj.15264 -
Current Oncology Reports Feb 2021This review will explore the latest in advanced imaging techniques, with a focus on the complementary nature of multiparametric, multimodality imaging using magnetic... (Review)
Review
PURPOSE OF REVIEW
This review will explore the latest in advanced imaging techniques, with a focus on the complementary nature of multiparametric, multimodality imaging using magnetic resonance imaging (MRI) and positron emission tomography (PET).
RECENT FINDINGS
Advanced MRI techniques including perfusion-weighted imaging (PWI), MR spectroscopy (MRS), diffusion-weighted imaging (DWI), and MR chemical exchange saturation transfer (CEST) offer significant advantages over conventional MR imaging when evaluating tumor extent, predicting grade, and assessing treatment response. PET performed in addition to advanced MRI provides complementary information regarding tumor metabolic properties, particularly when performed simultaneously. F-fluoroethyltyrosine (FET) PET improves the specificity of tumor diagnosis and evaluation of post-treatment changes. Incorporation of radiogenomics and machine learning methods further improve advanced imaging. The complementary nature of combining advanced imaging techniques across modalities for brain tumor imaging and incorporating technologies such as radiogenomics has the potential to reshape the landscape in neuro-oncology.
Topics: Brain Neoplasms; Diffusion Magnetic Resonance Imaging; Humans; Magnetic Resonance Imaging; Positron-Emission Tomography
PubMed: 33599882
DOI: 10.1007/s11912-021-01020-2 -
The EMBO Journal Feb 2021The roles of clock components in salt stress tolerance remain incompletely characterized in rice. Here, we show that, among OsPRR (Oryza sativa Pseudo-Response...
The roles of clock components in salt stress tolerance remain incompletely characterized in rice. Here, we show that, among OsPRR (Oryza sativa Pseudo-Response Regulator) family members, OsPRR73 specifically confers salt tolerance in rice. Notably, the grain size and yield of osprr73 null mutants were significantly decreased in the presence of salt stress, with accumulated higher level of reactive oxygen species and sodium ions. RNA sequencing and biochemical assays identified OsHKT2;1, encoding a plasma membrane-localized Na transporter, as a transcriptional target of OsPRR73 in mediating salt tolerance. Correspondingly, null mutants of OsHKT2;1 displayed an increased tolerance to salt stress. Immunoprecipitation-mass spectrometry (IP-MS) assays further identified HDAC10 as nuclear interactor of OsPRR73 and co-repressor of OsHKT2;1. Consistently, H3K9ac histone marks at OsHKT2;1 promoter regions were significantly reduced in osprr73 mutant. Together, our findings reveal that salt-induced OsPRR73 expression confers salt tolerance by recruiting HDAC10 to transcriptionally repress OsHKT2;1, thus reducing cellular Na accumulation. This exemplifies a new molecular link between clock components and salt stress tolerance in rice.
Topics: CLOCK Proteins; Cell Membrane; Gene Expression Regulation, Plant; Histone Deacetylases; Homeostasis; Loss of Function Mutation; Oryza; Plant Proteins; Promoter Regions, Genetic; Salt Tolerance; Sodium
PubMed: 33347628
DOI: 10.15252/embj.2020105086