Although previous studies have found that melatonin can promote seed germination, the mechanisms involved in perceiving and signaling melatonin remain poorly understood. In this study, it was found ...that melatonin was synthesized during cucumber seed germination with a peak in melatonin levels occurring 14 hr into germination. This is indicative of a correlation between melatonin synthesis and seed germination. Meanwhile, seeds pretreated with exogenous melatonin (1 μm) showed enhanced germination rates under 150 mm NaCl stress compared to water‐pretreated seeds under salinity stress. There are two apparent mechanisms by which melatonin alleviated salinity‐induced inhibition of seed germination. Exogenous melatonin decreased oxidative damage induced by NaCl stress by enhancing gene expression of antioxidants. Under NaCl stress, compared to untreated control, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by approximately 1.3–5.0‐fold, with a concomitant 1.4–2.0‐fold increase of CsCu‐ZnSOD, CsFe‐ZnSOD, CsCAT, and CsPOD in melatonin‐pretreated seeds. Melatonin also alleviated salinity stress by affecting abscisic acid (ABA) and gibberellin acid (GA) biosynthesis and catabolism during seed germination. Compared to NaCl treatment, melatonin significantly up‐regulated ABA catabolism genes (e.g., CsCYP707A1 and CsCYP707A2, 3.5 and 105‐fold higher than NaCl treatment at 16 hr, respectively) and down‐regulated ABA biosynthesis genes (e.g., CsNECD2, 0.29‐fold of CK2 at 16 hr), resulting in a rapid decrease of ABA content during the early stage of germination. At the same time, melatonin positively up‐regulated GA biosynthesis genes (e.g., GA20ox and GA3ox, 2.3 and 3.9‐fold higher than NaCl treatment at 0 and 12 hr, respectively), contributing to a significant increase of GA (especially GA4) content. In this study, we provide new evidence suggesting that melatonin alleviates the inhibitory effects of NaCl stress on germination mainly by regulating the biosynthesis and catabolism of ABA and GA4.
Biodiversity underpins the fundamental elements for human well-being including food security, human health and access to clean water. In 2010, the Aichi Targets were adopted by world leaders to ...address the crisis of biodiversity loss. Despite conservation efforts, none of the Aichi Targets have been fully met. However, comprehensive analysis of the reasons for failure in terms of implementation mechanisms is, to date, rare and limited in scope. Here, we demonstrate that most parties did not set effective national targets in accordance with the Aichi Targets, and investments, knowledge and accountability for biodiversity conservation have been inadequate to enable effective implementation. We recommend that the new global targets under the post-2020 Global Biodiversity Framework should be adopted by parties as the minimum national targets to achieve the 2050 Vision. We propose that financial resources for biodiversity conservation are substantially increased through a variety of sources, including the deployment of new economic instruments such as payments for ecosystem services. In addition, science-policy interfaces at all levels need to be strengthened to integrate scientific, Indigenous and local knowledge to support decision-making. We suggest that a compliance and accountability mechanism, based on monitoring systems, is created to provide transparent and credible review of parties' implementation of the new global targets.
Seed germination is a critical and complex process in the plant life cycle. Although previous studies have found that melatonin can promote seed germination under salt stress, the involvement of ...melatonin in the regulation of proteomic changes remains poorly understood. In this study, a total of 157 proteins were significantly influenced (ratio ≥ 2 or ≤ -2) by melatonin during seed germination under salt stress using a label-free quantitative technique. Our GO analysis revealed that several pathways were obviously regulated by melatonin, including ribosome biosynthesis, lipid metabolism, carbohydrate metabolism, and storage protein degradation. Not only stress-tolerant proteins but also proteins that produce ATP as part of glycolysis, the citric acid cycle, and the glyoxylate cycle were upregulated by melatonin. Overall, this study provides new evidence that melatonin alleviates the inhibitory effects of NaCl stress on seed germination by promoting energy production. This study is the first to provide insights at the proteomic level into the molecular mechanism of melatonin in response to salt stress in cucumber seeds. This may be helpful to further understand the role of melatonin in cucumber seed germination under stress conditions.
Tobias: A Random CNN Sees Objects Cao, Yun-Hao; Wu, Jianxin
IEEE transactions on pattern analysis and machine intelligence,
02/2024, Letnik:
46, Številka:
2
Journal Article
Recenzirano
This paper starts by revealing a surprising finding: without any learning, a randomly initialized CNN can localize objects surprisingly well. That is, a CNN has an inductive bias to naturally focus ...on objects, named as Tobias (" T he ob ject i s a t s ight") in this paper. This empirical inductive bias is further theoretically analyzed and empirically verified, and successfully applied to self-supervised learning as well as supervised learning. For self-supervised learning, a CNN is encouraged to learn representations that focus on the foreground object, by transforming every image into various versions with different backgrounds, where the foreground and background separation is guided by Tobias. Experimental results show that the proposed Tobias significantly improves downstream tasks, especially for object detection. This paper also shows that Tobias has consistent improvements on training sets of different sizes, and is more resilient to changes in image augmentations. Furthermore, we apply Tobias to supervised image classification by letting the average pooling layer focus on foreground regions, which achieves improved performance on various benchmarks.
Cucumber is a model cucurbitaceous plant with a known genome sequence which is important for studying molecular mechanisms of root development. In this study, RNA sequencing was employed to explore ...the mechanism of melatonin‐induced lateral root formation in cucumber under salt stress. Three groups of seeds were examined, that is, seeds primed without melatonin (CK), seeds primed in a solution containing 10 or 500 μmol/L melatonin (M10 and M500, respectively). These seeds were then germinated in NaCl solution. The RNA‐seq analysis generated 16,866,670 sequence reads aligned with 17,920 genes, which provided abundant data for the analysis of lateral root formation. A total of 17,552, 17,450, and 17,393 genes were identified from roots of the three treatments (CK, M10 and M500, respectively). The expression of 121 genes was significantly up‐regulated, and 196 genes were significantly down‐regulated in M500 which showed an obvious increase on the number of lateral roots. These genes were significantly enriched in 57 KEGG pathways and 16 GO terms (M500 versus CK). Based on their expression pattern, peroxidase‐related genes were selected as the candidates to be involved in the melatonin response. Several transcription factor families might play important roles in lateral root formation processes. A number of genes related to cell wall formation, carbohydrate metabolic processes, oxidation/reduction processes, and catalytic activity also showed different expression patterns as a result of melatonin treatments. This RNA‐sequencing study will enable the scientific community to better define the molecular processes that affect lateral root formation in response to melatonin treatment.
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•A simple one-step preparation of inhibitor-loaded mesoporous SiO2 nanocontainers was designed.•The new one-step method was efficient, energy-saving and organic solvents-free compared ...with traditional multi-step preparations.•The resultant nanocontainers had high uptake of inhibitor (∼16 wt.%) and possessed pH-responsive inhibitor release property.•The coating incorporated with the nanocontainers significantly improved the corrosion resistance of copper substrate.
We present a simple one-step method of preparing inhibitor-loaded mesoporous silica nanocontainers without extra steps such as template removal or inhibitors loading. The synthetic method is based on the high solubility of organic inhibitors in hydrophobic cores of template micelles. The resultant inhibitor (benzotriazole) and cetyltrimethyl ammonium bromide (CTAB) co-loaded silica nanocontainers had high uptake of inhibitor (∼16 wt.%) and possessed H+ ion-responsive inhibitor release property. When examined by scanning vibrating electrode technique, the coating doped with these nanocontainers exhibits effective corrosion protection property. These results suggest that the one-step synthetic method was efficient, energy-saving and organic solvents-free among others.
Summary
In eukaryotes, mechanisms such as alternative splicing (AS) and alternative translation initiation (ATI) contribute to organismal protein diversity. Specifically, splicing factors play ...crucial roles in responses to environment and development cues; however, the underlying mechanisms are not well investigated in plants. Here, we report the parallel employment of short‐read RNA sequencing, single molecule long‐read sequencing and proteomic identification to unravel AS isoforms and previously unannotated proteins in response to abscisic acid (ABA) treatment. Combining the data from the two sequencing methods, approximately 83.4% of intron‐containing genes were alternatively spliced. Two AS types, which are referred to as alternative first exon (AFE) and alternative last exon (ALE), were more abundant than intron retention (IR); however, by contrast to AS events detected under normal conditions, differentially expressed AS isoforms were more likely to be translated. ABA extensively affects the AS pattern, indicated by the increasing number of non‐conventional splicing sites. This work also identified thousands of unannotated peptides and proteins by ATI based on mass spectrometry and a virtual peptide library deduced from both strands of coding regions within the Arabidopsis genome. The results enhance our understanding of AS and alternative translation mechanisms under normal conditions, and in response to ABA treatment.
Significance Statement
In this study, a customized analytical pipeline was developed to study transcriptional and translational changes during the abscisic acid response in plants. Using single molecule long‐read sequencing and short‐read RNA sequencing, we identified numerous alternative spliced (AS) transcripts in Arabidopsis and characterized two new AS types. Proteomic identification indicates differentially expressed AS events were more likely to undergo protein translation. The entire workflow is applicable for other plant species.
The liver is vulnerable to sepsis, and sepsis-induced liver injury is closely associated with poor survival of sepsis patients. Studies have found that the overproduction of reactive oxygen species ...(ROS) is the major cause of oxidative stress, which is the main pathogenic factor for the progression of septic liver injury. The mitochondria are a major source of ROS. Mito-TEMPO is a mitochondria-specific superoxide scavenger. The aim of this study was to investigate the effect of Mito-TEMPO on lipopolysaccharide- (LPS-) induced sepsis mice. We found that Mito-TEMPO pretreatment inhibited inflammation, attenuated LPS-induced liver injury, and enhanced the antioxidative capability in septic mice, as evidenced by the decreased MDA content and the increased SOD activity. In addition, Mito-TEMPO restored mitochondrial size and improved mitochondrial function. Finally, we found that the levels of pyroptosis-related proteins in the liver of LPS-treated mice were lower after pretreatment with Mito-TEMPO. The mechanisms could be related to Mito-TEMPO enhanced antioxidative capability and improved mitochondrial function, which reflects the ability to neutralize ROS.
Abstract
Melatonin plays an important role in stress tolerance in plants. In this study, exogenous melatonin significantly alleviated the dwarf phenotype and inhibited the decrease of plant fresh ...weight induced by excess copper (Cu2+). Our results indicated that melatonin alleviated Cu2+ toxicity by improving Cu2+ sequestration, carbon metabolism and ROS (reactive oxygen species) scavenging, rather than by influencing the Cu2+ uptake under excess Cu2+ conditions. Transcriptome analysis showed that melatonin broadly altered gene expression under Cu2+ stress. Melatonin increased the levels of glutathione and phytochelatin to chelate excess Cu2+ and promoted cell wall trapping, thus keeping more Cu2+ in the cell wall and vacuole. Melatonin inhibited ROS production and enhanced antioxidant systems at the transcriptional level and enzyme activities, thus building a line of defense in response to excess Cu2+. The distribution of nutrient elements was recovered by melatonin which was disturbed by Cu2+. In addition, melatonin activated carbon metabolism, especially glycolysis and the pentose phosphate pathway, to generate more ATP, an intermediate for biosynthesis. Taken together, melatonin alleviated Cu2+ toxicity in cucumber via multiple mechanisms. These results will help to resolve the toxic effects of Cu2+ stress on plant growth and development. These results can be used for new strategies to solve problems associated with Cu2+ stress.
A full-duplex (FD) multiple antenna access point (AP) communicating with single antenna half-duplex (HD) spatially random users to support simultaneous uplink (UL)/downlink (DL) transmissions is ...investigated. Since FD nodes are inherently constrained by the loopback interference (LI), we study precoding schemes for the AP based on maximum ratio combining (MRC)/maximal ratio transmission (MRT), zero-forcing, and the optimal scheme for UL and DL sum rate maximization using tools from stochastic geometry. In order to shed insights into the systems performance, simple expressions for single antenna/perfect LI cancellation/negligible internode interference cases are also presented. We show that FD precoding at AP improves the UL/DL sum rate and hence a doubling of the performance of the HD mode is achievable. In particular, our results show that these impressive performance gains remain substantially intact even if the LI cancellation is imperfect. Furthermore, relative performance gap between FD and HD modes increases as the number of transmit/receive antennas becomes large, while with the MRC/MRT scheme, increasing the receive antenna number at FD AP, is more beneficial in terms of sum rate than increasing the transmit antenna number.
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