Exogenous Chemicals Used to Alleviate or Salvage Plants under Flooding/Waterlogging Stress: Their Biochemical Effects and Perspectives.

Plant flooding/waterlogging stress (FWS) can be a threat to food security worldwide due to climate change. To mitigate its potential devastation, numerous exogenous chemicals (ECs) have been used to demonstrate their effectiveness on alleviating FWS for the last 20 years. This review has summarized the most recent findings on use of various ECs as either nutrients or regulatory substances on crop plants under FWS and their roles involved in improving root respiration of seedlings, optimizing nutritional status, synthesizing osmotic regulators, enhancing the activity of antioxidant enzymes, adjusting phytohormone levels, maintaining photosynthetic systems, and activating flood-tolerance related gene expressions. The effect of ESs on alleviating plants under FWS proves to be beneficial and useful but rather limited unless they are applied on appropriate crops, at the right time, and with optimized methods. Further research should be focused on use of ESs in field settings and on their potential synergetic effect for more FWS tolerance.

Optimized management strategy increased grain yield, promoted nitrogen balance, and improved water productivity in winter wheat.

The increasing costs of agricultural production and environmental concerns reinforce the need to reduce resource inputs. Improvements in nitrogen (N) use efficiency (NUE) and water productivity (WP) are critical for sustainable agriculture. We aimed to optimize management strategy to increase wheat grain yield, promote N balance, and improve NUE and WP. A 3-year experiment was conducted with four integrated treatments: conventional practice treatment (CP); improvement of conventional practice treatment (ICP); high-yield management treatment (HY), which aimed for maximizing grain yield regardless of resource inputs cost; and integrated soil and crop system management treatment (ISM), which aimed for testing an optimal combination of sowing date, seeding rate, and fertilization and irrigation management. The average grain yield for ISM was 95.86% of that for HY and was 5.99% and 21.72% higher than that for ICP and CP, respectively. ISM promoted N balance as relatively higher aboveground N uptake, lower inorganic N residue, and lowest inorganic N loss. The average NUE for ISM was 4.15% lower than that for ICP and was remarkably higher than that for HY and CP by 26.36% and 52.37%, respectively. The increased soil water consumption under ISM was mainly due to its increased root length density. Along with a high level of grain yield, ISM obtained a relatively adequate water supply due to the effective use of soil water storage, thereby increasing the average WP by 3.63%-38.10% in comparison with other integrated management treatments. These results demonstrated that optimized management strategy (appropriately delaying sowing date, increasing seeding rate, and optimizing fertilization and irrigation management) used under ISM could promote N balance and improve WP while increasing grain yield and NUE in winter wheat. Therefore, ISM can be considered a recommendable management strategy in the target region.

Enlargement of the Middle Meningeal Artery may be an Initiating Factor of Chronic Subdural Hematoma: Three Rase reports and a Literature Review.

Middle Meningeal Artery (MMA) embolization for the treatment of refractory Chronic Subdural Hematoma (CSDH) was first described by Mandai et al. in 2000. Since then, more surgeons have begun to pay attention to such surgery to treat CSDH and explore the changes in the middle meningeal artery in the formation of hematomas. We have presented three cases of chronic subdural hematoma after head trauma and compared the diameter of the middle meningeal artery in MRA images before and after chronic subdural hematoma to discuss our new understanding of CSDH.

Role of the ratio of NSE serum concentration in evaluating the therapeutic effect on metastatic neuroendocrine neoplasms of the liver.

BACKGROUND: Neuron-specific enolase (NSE) is one of the biomarkers of neuroendocrine neoplasms (NEN). Its level of evidence is significantly lower than some other biomarkers. However, the ratio of NSE serum concentration (NSE ratio) before and after the treatment cycle may be a good tool for evaluating the therapeutic effect of metastatic neuroendocrine neoplasms of the liver (MNENOL). METHODS: We collected clinical cases of NEN with liver metastases, calculating the ratio of NSE in each case before and after the treatment cycle, using thin-slice computed tomography or magnetic resonance imaging as a reference to evaluate the therapeutic effect. We analyzed the correlation between NSE ratio and NSE serum concentration and curative effect, and then compared the evaluation performance of the two. RESULTS: We found that increase in the NSE ratio is a risk factor for the progression of MNENOL. Compared with NSE, NSE ratio has a greater advantage in evaluating the effect of MNENOL. NSE ratio is related to the curative effect of NEN, and the correlation is better than that of NSE. When judging whether NEN has new metastasis, the NSE ratio shows a similar effect to NSE, and there is no significant difference between the two. CONCLUSION: NSE ratio is more effective than NSE in evaluating the therapeutic effect of MNENOL, but it is not significantly different from NSE in terms of predicting new metastases.

The role of RNA-binding protein, microRNA and alternative splicing in seed germination: a field need to be discovered.

Seed germination is the process through which a quiescent organ reactivates its metabolism culminating with the resumption cell divisions. It is usually the growth of a plant contained within a seed and results in the formation of a seedling. Post-transcriptional regulation plays an important role in gene expression. In cells, post-transcriptional regulation is mediated by many factors, such as RNA-binding proteins, microRNAs, and the spliceosome. This review provides an overview of the relationship between seed germination and post-transcriptional regulation. It addresses the relationship between seed germination and RNA-binding proteins, microRNAs and alternative splicing. This presentation of the current state of the knowledge will promote new investigations into the relevance of the interactions between seed germination and post-transcriptional regulation in plants.

Proteomic analysis of wheat seeds produced under different nitrogen levels before and after germination.

The objective of this study was to investigate differentially abundant proteins (DAPs) of wheat seeds produced under two nitrogen levels (0 and 240 kg/ha) before and after germination. We selected samples at 8 and 72 h after imbibition (HAI) to identify DAPs by iTRAQ. The results showed 190 and 124 DAPs at 8 and 72 HAI, respectively. Alpha-gliadin and chlorophyll a-b binding protein showed the biggest difference in abundance before and after germination. In GO enrichment analysis, the most significantly enriched GO term was nutrient reservoir activity at 8 HAI and endopeptidase inhibitor activity at 72 HAI. Moreover, many DAPs involved in mobilization of stored nutrients and photosynthesis were mapped to KEGG pathways. Dough development time, dough stability time and seedling chlorophyll content under N240 were significantly higher than those under N0, which validated the results of proteomic analysis. These results are crucial for food nutrition and food processing.

Effects of Nitrogen Level during Seed Production on Wheat Seed Vigor and Seedling Establishment at the Transcriptome Level.

Nitrogen fertilizer is a critical determinant of grain yield and seed quality in wheat. However, the mechanism of nitrogen level during seed production affecting wheat seed vigor and seedling establishment at the transcriptome level remains unknown. Here, we report that wheat seeds produced under different nitrogen levels (N0, N168, N240, and N300) showed significant differences in seed vigor and seedling establishment. In grain yield and seed vigor, N0 and N240 treatments showed the minimum and maximum, respectively. Subsequently, we used RNA-seq to analyze the transcriptomes of seeds and seedlings under N0 and N240 at the early stage of seedling establishment. Gene Ontology (GO) term enrichment analysis revealed that dioxygenase-activity-related genes were dramatically upregulated in faster growing seedlings. Among these genes, the top three involved linoleate 9S-lipoxygenase (Traes_2DL_D4BCDAA76, Traes_2DL_CE85DC5C0, and Traes_2DL_B5B62EE11). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that pathways involved in nutrient mobilization and the antioxidant system showed enhanced expression under N240. Moreover, seeds with faster growing seedlings had a higher gene expression level of α-amylase, which was consistent with α-amylase activity. Taken together, we propose a model for seedling establishment and seed vigor in response to nitrogen level during seed production.

A loose endosperm structure of wheat seed produced under low nitrogen level promotes early germination by accelerating water uptake.

Water uptake is the fundamental requirement for the initiation and completion of seed germination that is a vital phase in the life cycle of seed plants. We found that seeds produced under four nitrogen levels showed significantly different germination speed. The objective of this study was to study the mechanism of rapid seed germination and explore which pathways and genes play critical roles in radicle protrusion. Anatomical data revealed that seed protein content affected endosperm structure of seeds. Moreover, scanning electron microscope maps showed that faster germinated seeds had a looser endosperm structure compared with other seeds. Subsequently, high throughout RNA-seq data were used to compare the transcriptomes of imbibed seeds with different germination speed. Gene ontology (GO) term enrichment analysis revealed that cell wall metabolism related genes significantly up-regulated in faster germinated seeds. In these genes, the top four were chitinase that had about fourfold higher expression in faster germinated seeds. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that faster germinated seeds had enhanced expression in glutathione metabolism. By combining these results, we propose a model for nitrogen fertilizer affects germination speed of wheat seed, which provide new insights into seed germination.

[Responses of winter wheat tillers at different positions to low temperature stress at stem elongation stage and their freezing resistance evaluation].

Taking two winter wheat cultivars Ji' nan 17 and Shannong 8355 as test materials, this paper measured the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and the malondialdehyde (MDA) and soluble protein contents in the functional leaves and sheaths of the tillers at different positions at stem elongation stage under low temperature stress, and then, the freezing resistance of the tillers was comprehensively evaluated by the methods of principal component analysis and cluster analysis. The results showed that under low temperature stress, the SOD, POD, and CAT activities in the functional leaves and sheaths of each tiller at stem elongation stage increased, but the MDA and soluble protein contents increased or decreased to some extent. By using principal component analysis and cluster analysis, the tillers of each cultivar were grouped into three kinds of freezing resistance type. For Ji' nan 17, the main stem, tiller I, and tiller II belonged to high freezing resistance type, the tiller III, tiller IV, and tiller I p belonged to medium freezing resistance type, and the tiller II p belonged to low freezing resistance type. For Shannong 8355, the main stem, tiller I, tiller II, and tiller III belonged to high freezing resistance type, the tiller IV and tiller I p belonged to medium freezing resistance type, and the tiller II p belonged to low freezing resistance type. It was concluded that the freezing resistance of the winter wheat tillers at different positions at stem elongation stage differed, with the lower position tillers being more resistant than the higher position tillers.