Phenylalanine Ammonia Lyase GmPAL1.1 Promotes Seed Vigor under High-Temperature and -Humidity Stress and Enhances Seed Germination under Salt and Drought Stress in Transgenic Arabidopsis.

Seed vigor is an important agronomic attribute, essentially associated with crop yield. High-temperature and humidity (HTH) stress directly affects seed development of plants, resulting in the decrease of seed vigor. Therefore, it is particularly important to discover HTH-tolerant genes related to seed vigor. Phenylalanine ammonia lyase (PAL, EC 4.3.1.24) is the first rate-limiting enzyme in the phenylpropanoid biosynthesis pathway and a key enzyme involved in plant growth and development and environmental adaptation. However, the biological function of PAL in seed vigor remains unknown. Here, GmPAL1.1 was cloned from soybean, and its protein was located in the cytoplasm and cell membrane. GmPAL1.1 was significantly induced by HTH stress in developing seeds. The overexpression of GmPAL1.1 in Arabidopsis (OE) accumulated lower level of ROS in the developing seeds and in the leaves than the WT at the physiological maturity stage under HTH stress, and the activities of SOD, POD, and CAT and flavonoid contents were significantly increased, while MDA production was markedly reduced in the leaves of the OE lines than in those of the WT. The germination rate and viability of mature seeds of the OE lines harvested after HTH stress were higher than those of the WT. Compared to the control, the overexpression of GmPAL1.1 in Arabidopsis enhanced the tolerance to salt and drought stresses during germination. Our results suggested the overexpression of GmPAL1.1 in Arabidopsis promoted seed vigor at the physiological maturation period under HTH stress and increased the seeds' tolerance to salt and drought during germination.

DNA methylation affects freezing tolerance in winter rapeseed by mediating the expression of genes related to JA and CK pathways.

Winter rapeseed is the largest source of edible oil in China and is especially sensitive to low temperature, which causes tremendous agricultural yield reduction and economic losses. It is still unclear how DNA methylation regulates the formation of freezing tolerance in winter rapeseed under freezing stress. Therefore, in this study, the whole-genome DNA methylation map and transcriptome expression profiles of freezing-resistant cultivar NTS57 (NS) under freezing stress were obtained. The genome-wide methylation assay exhibited lower levels of methylation in gene-rich regions. DNA methylation was identified in three genomic sequence contexts including CG, CHG and CHH, of which CG contexts exhibited the highest methylation levels (66.8%), followed by CHG (28.6%) and CHH (9.5%). Higher levels of the methylation were found in upstream 2 k and downstream 2 k of gene regions, whereas lowest levels were in the gene body regions. In addition, 331, 437, and 1720 unique differentially methylated genes (DMGs) were identified in three genomic sequence contexts in 17NS under freezing stress compared to the control. Function enrichment analysis suggested that most of enriched DMGs were involved in plant hormones signal transduction, phenylpropanoid biosynthesis and protein processing pathways. Changes of genes expression in signal transduction pathways for cytokinin (CK) and jasmonic acid (JA) implied their involvement in freezing stress responses. Collectively, these results suggested a critical role of DNA methylation in their transcriptional regulation in winter rapeseed under freezing stress.

The Copper Chaperone Protein Gene GmATX1 Promotes Seed Vigor and Seedling Tolerance under Heavy Metal and High Temperature and Humidity Stresses in Transgenic Arabidopsis.

Abiotic stresses such as high temperature, high humidity, and heavy metals are important factors that affect seed development and quality, and restrict yield in soybean. The ATX1-type copper chaperones are an important type of proteins that are used for maintaining intracellular copper ion homeostasis. In our previous study, a copper chaperone protein GmATX1 was identified in developing seeds of soybean under high temperature and humidity (HTH) stresses. In this study, the GmATX1 gene was isolated, and multiple alignment analysis showed that its encoding protein shared high sequence identities with other plant orthologues of copper chaperone proteins containing the HMA domain, and a conserved metal ion-binding site, CXXC. A subcellular localization assay indicated that GmATX1 was localized in the cell membrane and nucleus. An expression analysis indicated that GmATX1 was involved in seed development, and in response to HTH and heavy metal stresses in soybean. GmATX1-silent soybean seedlings were found to be more severely damaged than the control under HTH stress. Moreover, the silencing of GmATX1 reduced antioxidase activity and reactive oxygen species (ROS) scavenging ability in the seedling leaves. The overexpression of GmATX1 in Arabidopsis improved seed vigor and seedling tolerance, and enhanced antioxidase activity and ROS scavenging ability under HTH and heavy metal stresses. Our results indicated that GmATX1 could promote seed vigor and seedling tolerance to HTH and heavy metal stresses in transgenic Arabidopsis, and this promotion could be achieved by enhancing the antioxidase activity and ROS scavenging ability.

Quantitative proteomic, physiological and biochemical analysis of cotyledon, embryo, leaf and pod reveals the effects of high temperature and humidity stress on seed vigor formation in soybean.

BACKGROUND: Soybean developing seed is susceptible to high temperature and humidity (HTH) stress in the field, resulting in vigor reduction. Actually, the HTH in the field during soybean seed growth and development would also stress the whole plant, especially on leaf and pod, which in turn affect seed growth and development as well as vigor formation through nutrient supply and protection. RESULTS: In the present study, using a pair of pre-harvest seed deterioration-sensitive and -resistant cultivars Ningzhen No. 1 and Xiangdou No. 3, the comprehensive effects of HTH stress on seed vigor formation during physiological maturity were investigated by analyzing cotyledon, embryo, leaf, and pod at the levels of protein, ultrastructure, and physiology and biochemistry. There were 247, 179, and 517 differentially abundant proteins (DAPs) identified in cotyledon, embryo, and leaf of cv. Xiangdou No. 3 under HTH stress, while 235, 366, and 479 DAPs were identified in cotyledon, embryo, and leaf of cv. Ningzhen No. 1. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Most of the DAPs identified were found to be involved in major metabolic pathways and cellular processes, including signal transduction, tricarboxylic acid cycle, fatty acid metabolism, photosynthesis, protein processing, folding and assembly, protein biosynthesis or degradation, plant-pathogen interaction, starch and sucrose metabolism, and oxidative stress response. The HTH stress had less negative effects on metabolic pathways, cell ultrastructure, and physiology and biochemistry in the four organs of Xiangdou No. 3 than in those of Ningzhen No. 1, leading to produce higher vigor seeds in the former. CONCLUSION: High seed vigor formation is enhanced by increasing protein biosynthesis and nutrient storage in cotyledon, stronger stability and viability in embryo, more powerful photosynthetic capacity and nutrient supply in leaf, and stronger protection in pod under HTH stress. These results provide comprehensive characteristics of leaf, pod and seed (cotyledon and embryo) under HTH stress, and some of them can be used as selection index in high seed vigor breeding program in soybean.

Effects of Haloperidol on Delirium in Adult Patients: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis was to investigate whether or not the use of haloperidol could reduce the incidence of delirium in adult patients. SUBJECTS AND METHODS: PubMed, Embase, the Cochrane Library, Elsevier, Wiley, and Ovid were searched for randomized controlled trials and prospective interventional cohort studies that compared haloperidol with placebo for delirium prophylaxis or with second generation antipsychotics for delirium treatment. The primary end point was the incidence and severity of delirium. After reviewing 272 relevant articles, 10 studies with 1,861 patients were finally included (haloperidol vs. placebo in 8 studies [n = 1,734], and haloperidol vs. second-generation antipsychotics in 2 studies [n = 127]). Revman 5.3 was used for the data analysis. RESULTS: Compared with placebo, a high dose of prophylactic haloperidol (≥5 mg/day) may help reduce the incidence of delirium in surgical patients (risk ratio 0.50, 95% CI 0.32, 0.79). There were no differences in the duration of delirium, QTc interval prolongation, extrapyramidal symptoms, intensive care unit stay, hospital stay, or mortality between the haloperidol and placebo groups. For delirium treatment, haloperidol exhibited similar effects as the second-generation antipsychotics. CONCLUSIONS: In this study, the limited available data revealed that prophylaxis haloperidol at a dose of ≥5 mg/day might help reduce delirium in adult surgical patients. Further outcome studies with larger sample sizes are required to confirm these findings.

Isolation, Identification and Characterization of a New Type of Lectin with α-Amylase Inhibitory Activity in Chickpea (Cicer arietinum L.).

BACKGROUND: Plant lectins are a group of highly diverse proteins that possess at least one non-catalytic domain that binds reversibly to a specific mono- or oligosaccharide. So far, only seven members in the lectin-arcelin-αAI1 supergene family in legume lectins have been reported to have inhibitory activity of α-amylases. OBJECTIVE & METHODS: A proteinaceous α-amylase inhibitor was isolated and purified using Ammonium sulfate precipitation (ASP), Ion exchange chromatography (IEC) and Reversed phase liquid chromatography (RPLC) from the mature seeds of chickpea. RESULTS & CONCLUSION: Identification by Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS-MS) indicated that the purified proteinaceous α-amylase inhibitor was a chickpea lectin CAL in GenBank (accession No. AGL46982.1). CAL had 227 aa containing a hemopexin- like repeats domain and was a cytoplasm protein. It had very low (<17%) identity with seven members in the lectin-arcelin-aAI1 supergene family in legumes that have α-amylase inhibitory activity. The purified CAL derived from prokaryotic expression was confirmed to have inhibitory activity against various α-amylases. The inhibitory activity of CAL against various α-amylases was severely affected by temperature, pH, incubation time, substrate concentration and CAL protein concentration. Feeding CAL reduced the weight of potato beetle larvae by 27.21% (P<0.05) and survival rate by 6.67% (P>0.05). Our results indicated that CAL is a new type of lectin with inhibitory activity against α-amylases in legume lectins, which can be used as a candidate in genetic engineering for breeding for pest resistance.