63 research outputs found

    MicroRNA390-Directed TAS3 Cleavage Leads to the Production of tasiRNA-ARF3/4 During Somatic Embryogenesis in Dimocarpus longan Lour

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    Trans-acting short-interfering RNAs (tasiRNAs) originate from TAS3 families through microRNA (miRNA) 390-guided cleavage of primary transcripts and target auxin response factors (ARF3/-4), which are involved in the normal development of lateral roots and flowers in plants. However, their roles in embryo development are still unclear. Here, the pathway miR390-TAS3-ARF3/-4 was identified systematically for the first time during somatic embryo development in Dimocarpus longan. We identified the miR390 primary transcript and promoter. The promoter contained cis-acting elements responsive to stimuli such as light, salicylic acid, anaerobic induction, fungal elicitor, circadian control and heat stress. The longan TAS3 transcript, containing two miR390-binding sites, was isolated; the miR390- guided cleavage site located near the 3' end of the TAS3 transcript was verified. Eight TAS3-tasiRNAs with the 21-nucleotide phase were found among longan small RNA data, further confirming that miR390-directed TAS3 cleavage leads to the production of tasiRNA in longan. Among them, TAS3_5'D5+ and 5'D6+ tasiRNAs were highly abundant, and verified to target ARF3 and -4, implying that miR390-guided TAS3 cleavage with 21-nucleotide phase leading to the production of tasiRNA-ARF is conserved in plants. Pri-miR390 was highly expressed in friable-embryogenic callus (EC), and less expressed in incomplete compact pro-embryogenic cultures,while miR390 showed its lowest expression in EC and highest expression in torpedo-shaped embryo. DlTAS3 and DlARF4 both exhibited their lowest expressions in EC, and reached their peaks in the globular embryos stage, which were mainly inversely proportional to the expression of miR390, especially at the GE to CE stages. While DlARF3 showed little variation from the EC to torpedo-shaped embryos stages, and exhibited its lowest expression in the cotyledonary embryos stage. There was a general lack of correlation between the expressions of DlARF3 and miR390. In addition, miR390, DlTAS3, DlARF3, and -4 were up-regulated by 2,4-D in a concentration-dependent manner. They were also preferentially expressed in roots, pulp, and seeds of β€˜Sijimi’ longan, implying their extended roles in the development of longan roots and fruit. This study provided insights into a possible role of miR390-tasiRNAs-ARF in plant somatic embryo development

    The predictive role of soluble programmed death ligand 1 in digestive system cancers

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    IntroductionThe prognostic role of soluble programmed death ligand 1 (sPD-L1) in digestive system cancers (DSCs) remains inconclusive. This study aimed to explore the predictive value of sPD-L1 expression in DSCs.MethodsComprehensive searches were run on the electronic databases (PubMed, Web of Science, EMBASE, and the Cochrane Library) to identify studies that assessed the prognostic role of sPD-L1 in DSCs. Review Manager software (version 5.3) was used for all analyses. Pooled data for survival outcomes were measured as hazard ratios (HRs), 95% confidence intervals (CIs), and odds ratios and their 95% CIs.ResultsThe search identified 18 studies involving 2,070 patients with DSCs. The meta-outcome revealed that a high level of sPD-L1 was related to poorer overall survival (HR, 3.06; 95% CI: 2.22–4.22, p<0.001) and disease-free survival (HR, 2.53; 95% CI: 1.67–3.83, p<0.001) in DSCs. Individually, the prognostic significance of high level of sPD-L1 expression was the highest in hepatic cell carcinoma (HR, 4.76; p<0.001) followed by gastric cancer (HR=3.55, p<0.001).ConclusionsPD-L1 may be a prognostic factor in DSCs for overall survival and disease-free survival. Inflammatory cytokines, treatment approaches, and other factors may affect the expression of sPD-L1. Therefore, the prognostic value of sPD-L1 for recurrence and metastasis should be further investigated. sPD-L1 may also predict response to treatment. Well-designed prospective studies with standard assessment methods should be conducted to determine the prognostic value of sPD-L1 in DSCs

    Skills' sets and shared benefits: perceptions of resettled people from the Yangtze-Huai River Diversion Project in China

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    Development induced displacement and resettlement (DIDR) projects should share their benefits with those affected by them. This paper shows that in the case of the Yangtze-Huai River Diversion Project in China perceptions of compensation received differs amongst different groups of resettled people even if levels of compensation are similar. Based on a survey with displaced people, a fuzzy comprehensive evaluation concludes that those with generic skills’ sets are the most satisfied, mainly because they are able to find new work and re-establish livelihoods after resettlement more quickly. On the other hand, those with only agricultural skills find it difficult to re-establish their livelihood and are often dissatisfied. Finally, those who did not have any work before resettlement were found to be satisfied overall as their life quality is said to have improved. The skills of those affected are therefore a key explanatory factor for satisfaction with compensation following resettlement

    Genetic Insight into Yield-Associated Traits of Wheat Grown in Multiple Rain-Fed Environments

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    Background: Grain yield is a key economic driver of successful wheat production. Due to its complex nature, little is known regarding its genetic control. The goal of this study was to identify important quantitative trait loci (QTL) directly and indirectly affecting grain yield using doubled haploid lines derived from a cross between Hanxuan 10 and Lumai 14. Methodology/Principal Findings: Ten yield-associated traits, including yield per plant (YP), number of spikes per plan

    Overexpression of a Common Wheat Gene TaSnRK2.8 Enhances Tolerance to Drought, Salt and Low Temperature in Arabidopsis

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    Drought, salinity and low temperatures are major factors limiting crop productivity and quality. Sucrose non-fermenting1-related protein kinase 2 (SnRK2) plays a key role in abiotic stress signaling in plants. In this study, TaSnRK2.8, a SnRK2 member in wheat, was cloned and its functions under multi-stress conditions were characterized. Subcellular localization showed the presence of TaSnRK2.8 in the cell membrane, cytoplasm and nucleus. Expression pattern analyses in wheat revealed that TaSnRK2.8 was involved in response to PEG, NaCl and cold stresses, and possibly participates in ABA-dependent signal transduction pathways. To investigate its role under various environmental stresses, TaSnRK2.8 was transferred to Arabidopsis under control of the CaMV-35S promoter. Overexpression of TaSnRK2.8 resulted in enhanced tolerance to drought, salt and cold stresses, further confirmed by longer primary roots and various physiological characteristics, including higher relative water content, strengthened cell membrane stability, significantly lower osmotic potential, more chlorophyll content, and enhanced PSII activity. Meanwhile, TaSnRK2.8 plants had significantly lower total soluble sugar levels under normal growing conditions, suggesting that TaSnRK2.8 might be involved in carbohydrate metabolism. Moreover, the transcript levels of ABA biosynthesis (ABA1, ABA2), ABA signaling (ABI3, ABI4, ABI5), stress-responsive genes, including two ABA-dependent genes (RD20A, RD29B) and three ABA-independent genes (CBF1, CBF2, CBF3), were generally higher in TaSnRK2.8 plants than in WT/GFP controls under normal/stress conditions. Our results suggest that TaSnRK2.8 may act as a regulatory factor involved in a multiple stress response pathways

    Microdissection of Shoot Meristem Functional Domains

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    The shoot apical meristem (SAM) maintains a pool of indeterminate cells within the SAM proper, while lateral organs are initiated from the SAM periphery. Laser microdissection–microarray technology was used to compare transcriptional profiles within these SAM domains to identify novel maize genes that function during leaf development. Nine hundred and sixty-two differentially expressed maize genes were detected; control genes known to be upregulated in the initiating leaf (P0/P1) or in the SAM proper verified the precision of the microdissections. Genes involved in cell division/growth, cell wall biosynthesis, chromatin remodeling, RNA binding, and translation are especially upregulated in initiating leaves, whereas genes functioning during protein fate and DNA repair are more abundant in the SAM proper. In situ hybridization analyses confirmed the expression patterns of six previously uncharacterized maize genes upregulated in the P0/P1. P0/P1-upregulated genes that were also shown to be downregulated in leaf-arrested shoots treated with an auxin transport inhibitor are especially implicated to function during early events in maize leaf initiation. Reverse genetic analyses of asceapen1 (asc1), a maize D4-cyclin gene upregulated in the P0/P1, revealed novel leaf phenotypes, less genetic redundancy, and expanded D4-CYCLIN function during maize shoot development as compared to Arabidopsis. These analyses generated a unique SAM domain-specific database that provides new insight into SAM function and a useful platform for reverse genetic analyses of shoot development in maize

    Rethinking vulnerability and human behaviour in arid and semi-arid regions in northwestern China

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    The relationship between human behaviour and vulnerability is interactive, especially in arid and semi-arid regions. This paper analyses vulnerability and human behaviour in the core areas of Qilian Mountains National Park, which is located in Qilian and Sunan counties. We used the vulnerability index and grey correlation degree methods to analyse the data. The results show that from 2005 to 2017, the vulnerability degree in the Qilian Mountain area decreased gradually (Qilian County vulnerability decreased from 0.0357 to - 0.2237, and Sunan County vulnerability decreased from 0.1428 to - 0.4489). In 2017, the degree had reached its lowest value due to central and local government policy (- 0.2237 and - 0.4489). Considering that human behaviour contributed to the vulnerability degree, we find that land use and agricultural development mode, the acceleration of industrialisation and changes in the spatial patterns of human activities, and the development of urbanization and changes in resident identities are the main concepts driving the relationship between human behaviour and vulnerability. The innovative assessment indicators developed in this study can be applied to thoroughly explore the relationship between human behaviour and vulnerability and to find the influencing factors. Under certain conditions, this approach can be applied to vulnerability research in specific countries and regions

    Infrastructure Investment and Regional Economic Growth: Evidence from Yangtze River Economic Zone

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    To better understand the impacts of infrastructure investment on economic growth and, we used Cobb-Douglas production function model to develop the stock of public infrastructure capital into the economic growth model. It applies spatial panel data model effect analysis to statistical data of the Yangtze River Economic Zone with 131 cities from 2003 to 2016 and investigates the relationship between different types of public infrastructure capital stock and regional economic growth in different periods. The empirical results show that (1) the economic growth of the cities in the Yangtze River Economic Zone has characteristics of significant spatial dependence, the degree and significance of spatial dependence are gradually declining, and the spatial agglomeration of the economic growth in the cities in the region is relatively stable. (2) Different types of public infrastructure capital stock have distinct spatial effects on regional economic growth. The capital stock of energy infrastructure significantly promotes global economic growth. The capital stock of transportation infrastructure significantly stimulates the local economic growth and inhibits the economic growth of the adjacent areas. The capital stock of water-related infrastructure restrains local economic growth and promotes economic growth in adjacent areas. These findings indicate that increasing investment in public infrastructure development in the Yangtze River Economic Zone remains an effective measure to promote regional economic growth. Under the premise of limited resources, taking full account of the effects of various types of investment can promote the mutual benefit of the economies in the region and effectively achieve the strategic objectives for the Yangtze River Economic Zone
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