CPTA treatment reveals potential transcription factors associated with carotenoid metabolism in flowers of Osmanthus fragrans

Osmanthus fragrans is one of the top ten traditional flowers in China.It is divided into three different groups according to its color.α-Carotene and β-carotene are the main determinants to distinguish the color differences between three groups.However,the dominant genes and transcription factors involved in carotenoid metabolism remain unclear.CPTA treatment(0.7mmol·L−1)remarkably promoted lycopene,α-carotene and β-carotene contents in flowers.Transcriptome sequencing analysis revealed that CPTA treatment could trigger chain reactions in carotenoid metabolism pathway genes.Four up-regulated and 10 down-regulated transcription factors which have close association with carotenoid variation were significantly induced by CPTA treatment.The up-regulated TFs such as MYB43,MYB123,HSF,were further subjected to transcript expression determination in different cultivars with drastic colors.Among them,transcript expression of four up-regulated TFs coincided with the carotenoid accumulation in different cultivars.We selected up-regulated OfMYB43 to verify its function,which is related to stress tolerance and transcriptional regulation.Transient overexpression of OfMYB43 in O.fragrans flowers showed that it could remarkably promote the expression of PDS,ZISO,LCYE and CCD4,leading to increased accumulation of β-branch carotenoids.OfMYB43 was a potential positive regulator of carotenoid biosynthesis in O.fragrans flowers.This study provides insight into the molecular mechanism of carotenoid metabolism in O.fragrans.

Whole-genome resequencing of Osmanthus fragrans provides insights into flower color evolution

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.

Construction of China Osmanthus City and Intellectual Property Right Protection in Xianning City in the Context of Three New Developments

Xianning City of Hubei Province is one of the five major traditional osmanthus producing areas in the world and the hometown of osmanthus in China. Xianning is constructing China Osmanthus City in the whole city. This paper first introduces the main characteristics of the osmanthus industry in Xianning City, and analyzes the characteristics of traditional knowledge, biological genetic resources, new plant varieties, patents, geographical indications, and trademarks. Then, it studies the intellectual property resources of the osmanthus industry, and analyzes the main problems existing in the construction of China Osmanthus City and intellectual property right protection. Finally, it comes up with constructive recommendations including applying for China and Globally Important Agricultural Heritage Systems, developing colored-leaf osmanthus varieties, creating a regional public brand of osmanthus specialty products, and building a new development pattern of osmanthus industry.

Receptor-mediated targeted drug delivery systems for treatment of inflammatory bowel disease: Opportunities and emerging strategies

Inflammatory bowel disease(IBD)is a chronic intestinal disease with painful clinical manifestations and high risks of cancerization.With no curative therapy for IBD at present,the development of effective therapeutics is highly advocated.Drug delivery systems have been extensively studied to transmit therapeutics to inflamed colon sites through the enhanced permeability and retention(EPR)effect caused by the inflammation.However,the drug still could not achieve effective concentration value that merely utilized on EPR effect and display better therapeutic efficacy in the inflamed region because of nontargeted drug release.Substantial researches have shown that some specific receptors and cell adhesion molecules highly expresses on the surface of colonic endothelial and/or immune cells when IBD occurs,ligandmodified drug delivery systems targeting such receptors and cell adhesion molecules can specifically deliver drug into inflamed sites and obtain great curative effects.This review introduces the overexpressed receptors and cell adhesion molecules in inflamed colon sites and retrospects the drug delivery systems functionalized by related ligands.Finally,challenges and future directions in this field are presented to advance the development of the receptor-mediated targeted drug delivery systems for the therapy of IBD.