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The tolerance of rice anaerobic germination (AG) is the main limiting factor for direct seeding application, yet the genetics mechanism is still in its infancy. In the study, recombinant inbred lines population of TD70 Japonica cultivar and Kasalath Indica cultivar, was employed to construct a high-density genetic map by whole genome re-sequencing. As a result, a genetic map containing 12,328 bin-markers was constructed and a total of 50 QTLs were then detected for CL (coleoptile length), CD (coleoptile diameter), CSA (coleoptile surface area) and CV (coleoptile volume) related traits in the two stages of anaerobic treatment using complete interval mapping method (inclusive composite interval mapping, ICIM). Among the four traits associated with coleoptile, coleoptile volume had the largest number of QTLs (17), followed by coleoptile diameter (16), and coleoptile length had 5 QTLs. These QTLs could explain phenotypic contribution rates ranging from 0.34% to 11.17% and LOD values ranging from 2.52 to 11.57. Combined with transcriptome analysis, 31 candidate genes were identified. Furthermore, 12 stable QTLs were used to detect the aggregation effect analysis. Besides, It was found that individuals with more aggregation synergistic alleles had higher phenotypic values in different environments. Totally, high-density genetic map, QTL mapping and aggregation effect analysis of different loci related to the anaerobic germination of rice seeds were conducted to lay a foundation for the fine mapping of related genes in subsequent assisted breeding. [ABSTRACT FROM AUTHOR]

Flue-curing of top leaves with stems is a widely applied curing technology. Owing to the presence of stems, the quality of flue-cured leaves was significantly improved. However, the contribution of stems to flue-cured leaves is still unknown. In this study, the differences in physicochemical properties and metabolomics data between separated leaves (stem(-)) and leaves with stems (stem(+)) were investigated. The metabolic profiling of stem (+) was significantly different from that of stem(-), with phytohormone indole3-acetic acid (IAA) being one of the most differential metabolites. The presence of stems reduced the rate of water loss in leaves, which led to less ROS accumulation, higher antioxidant enzyme activities and a lower level of membrane lipid peroxidation in stem(+) than in stem(-). The presence of stems also helped maintain the cellular membrane integrity of leaf cells by preventing the accumulation of IAA in leaf cells. Better cellular membrane integrity during flue-curing means a lower risk of leaf browning. In addition, stem(+) had a lower starch content than stem(-) because of a higher level of amylase activity. In summary, these results indicated that the presence of stems caused metabolism changes in leaves, prevented flue-cured leaves from browning and enhanced starch degradation in leaves during flue-curing. [ABSTRACT FROM AUTHOR]

Chenopodium quinoa is a crop with outstanding tolerance to saline soil, but long non-coding RNAs (LncRNAs) expression profile driven by salt stress in quinoa has rarely been observed yet. Based on the highquality quinoa reference genome and high-throughput RNA sequencing (RNA-seq), genome-wide identification of LncRNAs was performed, and their dynamic response under salt stress was then investigated. In total, 153,751 high-confidence LncRNAs were discovered and dispersed intensively in chromosomes. Expression profile analysis demonstrated significant differences between LncRNAs and coding RNAs. Under salt stress conditions, 4,460 differentially expressed LncRNAs were discovered, of which only 54 were differentially expressed at all the stress time points. Besides, strongly significantly correlation was observed between salt-responsive LncRNAs and their closest neighboring genes (r = 0.346, p-value < 2.2e-16). Furthermore, a weighted co-expression network was then constructed to infer the potential biological functions of LncRNAs. Seven modules were significantly correlated with salt treatments, resulting in 210 hub genes, including 22 transcription factors and 70 LncRNAs. These results indicated that LncRNAs might interact with transcription factors to respond to salinity stress. Gene ontology enrichment of the coding genes of these modules showed that they were highly related to regulating metabolic processes, biological regulation and response to stress. This study is the genome-wide analysis of the LncRNAs responding to salt stress in quinoa. The findings will provide a solid framework for further functional research of salt responsive LncRNAs, contributing to quinoa genetic improvement. [ABSTRACT FROM AUTHOR]

Quinoa is a gluten-free food crop that contains all the essential amino acids and vitamins. The selection of proper housekeeping and tissue-specific genes is the crucial prerequisite for gene expression analysis using the common approach, real-time quantitative PCR (RT-qPCR). In this study, we identified 40 novel candidate housekeeping genes by the minimum transcript per million (TPM), coefficient of variation (CV) and maximum fold change (MFC) methods and 19 candidate tissuespecific genes by the co-expression network method based on an RNA-seq dataset that included 53 stem, leaf, flower and seed samples, as well as additional shoot and root samples under different stresses. The expression stability of 12 housekeeping and tissue-specific genes, as well as that of another two traditionally used housekeeping genes, was further evaluated using qPCR and ranked using NormFinder, BestKeeper and the comparative delta-Ct method. The results demonstrated that MIF, RGGA, VATE and UBA2B were ranked as the top four most stable candidate housekeeping genes. qPCR analysis also revealed three leaf-specific genes and five root-specific genes, but no stem-specific gene was identified. Gene Ontology (GO) enrichment analysis identified that housekeeping genes were mainly enriched in the small molecule metabolic process, organonitrogen compound metabolic process, NAD binding and ligase activity. In addition, tissue-specific genes are closely associated with the major functions of a specific tissue. Specifically, GO terms "photosynthesis" and "thylakoid" were most significantly overrepresented in candidate leaf-specific genes. The novel housekeeping and tissue-specific genes in our study will enable better normalization and quantification of transcript levels in quinoa. [ABSTRACT FROM AUTHOR]

Highly fluorescent CdTe quantum dots (Q-dots) stabilized by 3-mercaptopropionic acid (MPA)were prepared by an aqueous solution approach and used as fluorescent labels in detectinga cancer marker, carcinoembryonic antigen (CEA), expressed on human colon carcinomacell line LS 180. Nonspecific adsorptions of CdTe Q-dots on carcinoma cells were observedand effectively eliminated by replacing MPA with a thiolated PEG (poly(ethylene glycol),Mn = 750) synthesized according to literature. It was unexpectedly found out that thePEG-coated CdTe Q-dots exhibited very strong and specific affinity to anti-CEAmonoclonal antibody rch 24 (rch 24mAb). The resultant CdTe–(rch 24mAb) conjugateswere successfully used in detections of CEA expressed on the surface of cell lineLS 180. Further experiments demonstrated that the fluorescent CdTe Q-dotsexhibited much better photostability and a brighter fluorescence than FITC,which consequently led to a higher efficiency in the cancer marker detection. [ABSTRACT FROM AUTHOR]

A one-pot reaction process was developed to synthesize highly dispersible, superparamagnetic Fe3O4nanoflowers; the potential of these nanoflowers as MRI contrast agents was investigated. [ABSTRACT FROM AUTHOR]

A one-pot reaction process was developed to synthesize highly dispersible, superparamagnetic Fe3O4nanoflowers; the potential of these nanoflowers as MRI contrast agents was investigated. [ABSTRACT FROM AUTHOR]

The development of new types of high-performance nanoparticulate MR contrast agents with either positive (T1) or dual-contrast (both positive and negative, T1 + T2) ability is of great importance. Here we report a facile synthesis of ultrasmall PEGylated iron oxide nanoparticles for dual-contrast T1- and T2-weighted MRI. The produced superparamagnetic iron oxide nanoparticles (SPIONs) are of high crystallinity and size uniformity with an average diameter of 5.4 nm, and can be individually dispersed in the physiological buffer with high stability. The SPIONs reveal an impressive saturation magnetization of 94 emu g [?] 1 Fe3O4, the highest r1 of 19.7 mM [?] 1 s [?] 1 and the lowest r2/r1 ratio of 2.0 at 1.5 T reported so far for PEGylated iron oxide nanoparticles. T1- and T2-weighted MR images showed that the SPIONs could not only improve surrounding water proton signals in the T1-weighted image, but induce significant signal reduction in the T2-weighted image. The good contrast effect of the SPIONs as T1 + T2 dual-contrast agents might be due to its high magnetization, optimal nanoparticle size for T1 + T2 dual-contrast agents, high size monodispersity and excellent colloidal stability. In vitro cell experiments showed that the SPIONs have little effect on HeLa cell viability. [ABSTRACT FROM AUTHOR]