Enhancing Drought Tolerance in Wheat through Improving MorphoPhysiological and Antioxidants Activities of Plants by the Supplementation of Foliar Silicon

The main objective of the research is to assess the role of foliar application of silicon (Si) for enhancing the survival ability of wheat under drought stress through improving its morphology, physicochemical and antioxidants activities. Treatments were five doses of Si at the rate of 2, 4, 6 and 8 mM and a control. After completion of seeds germination, pots were divided into four distinct groups at various field capacity (FC) levels, such as 100% FC (well-irrigated condition), 75% FC (slight water deficit), 50% FC (modest water deficit) and 25% FC (severe water deficit stress condition). Foliar application of Si at the rate of 2, 4, 6 and 8 mM and a control were given after 30 days of sowing at the tillering stage of wheat. Findings of the present investigation indicated that increasing the level of water deficit stress reduced the morphological parameters (such as root and shoot fresh and dry-biomass weight) and physico-biochemical events ((such as chlorophyll contents by estimating SPAD value), total free amino acid (TFAA), total soluble sugar (TSS), total soluble protein (TSP), total proline (TP), CAT (catalase), POD (peroxidase), SOD (superoxide dismutase) and APX (ascorbate peroxidase)) of wheat; while foliar application of Si at 6 mM at tillering stage enhanced the drought tolerance in wheat by increasing morphology and physiochemical characters under all levels of drought stress. Similarly, antioxidants activities in wheat also enhanced by the application of Si at 6 mM under normal as well as all drought stress levels. Therefore, it may be concluded that foliar application of Si at 6 mM at the tillering stage of wheat is an important indication for increasing the drought tolerance by improving the morphology, physico-biochemical and antioxidants activities in plants under deficit water (drought) conditions.     

内蒙古植被枯黄期变化及其与气候和植被生产力的关系

基于2001—2018年MODIS NDVI数据,采用累计归一化植被指数(NDVI)的Logistic曲线曲率极值法,识别内蒙古植被枯黄期及其时空变化特征,并在生态区尺度上分析枯黄期对气候因子和NDVI的响应特征。结果表明: 研究期间,内蒙古植被平均枯黄期主要集中在第260～280天。森林生态区枯黄期为第270～280天,从南向北推迟;草原生态区枯黄期最早,介于第257～273天,从东北向西南逐渐推迟;荒漠生态区枯黄期为第270～283天,东北向西南呈推迟态势。2001—2018年间,3个生态区植被枯黄期均呈不显著推迟趋势。植被生产力从东北向西南逐渐降低,在时间上呈增加趋势的面积大于呈减小趋势的面积。全内蒙古和各生态区植被枯黄期受季前2～3个月降水量的正面影响较大,与季前平均温度、最高温度和最低温度均呈正相关关系。全内蒙古和各生态区,8和9月植被生产力的增加(或减少)将推迟(或提前)植被枯黄期,而6和7月植被生产力的增加(或减少)将提前(或推迟)草原和荒漠生态区植被枯黄期。     

叶绿素结合蛋白CP24介导光照响应基因StRSM 1调控叶绿素积累

单MYB转录因子成员RSM(RADIALIS-like SANT/MYB)突变,倒置黑暗诱导的叶绿素减少,原因有待确定;为了揭示RSM如何调控叶绿素积累,本研究运用基因工程途径,获得了普通烟草和马铃薯体内抑制和过量表达StRSM 1阳性转化株系,测定了阳性转化株系的叶绿素积累等生理表型;结果显示,普通烟草和马铃薯体内抑制RSM 1表达,显著增加了叶绿素积累,叶色随之加深;RSM 1过量表达,显著减少叶绿素积累,叶色变浅。叶绿素代谢相关基因表达测定结果显示,StRSM 1过量表达增加了黑暗下叶绿素结合蛋白CP24基因的表达,改变了其表达模式。以上结果表明,转录因子StRSM 1响应光照反向调控叶绿素积累,叶绿素结合蛋白CP24参与了StRSM 1对叶绿素积累的调控。结果有助于进一步明确RSM 1如何响应光照和深刻理解RSM 1参与的光照响应。     

Using microwave irradiation in Marchi's method for demonstrating degenerated myelin

Conventional methods for histological preparation of degenerated myelin are time-consuming and difficult. The purpose of our study was to shorten the time required for the procedure and to obtain better quality results for light microscopic demonstration of degenerated myelin in the central and peripheral nervous systems by using microwave irradiation. Rat brain and sciatic nerve were used for the study. The middle cerebral artery was occluded and the sciatic nerve was cut to produce myelin degeneration. Marchi's method was used for staining degenerated myelin. Fixation for light microscopy that would take two days using the conventional procedure was completed in 16.5–18.5 min using microwave irradiation. While staining of degenerated myelin requires 10 days for the conventional Marchi method, we decreased it to 7 h for brain tissue and 1 h for sciatic nerve by using the microwave oven. Moreover, a better quality preparation was achieved in the groups stained under microwave irradiation than those prepared by the conventional method.     

Polymorphisms of hemochromatosis, and alpha-1 antitrypsin genes in Egyptian HCV patients with and without hepatocellular carcinoma

Hereditary hemochromatosis and alpha-1antitrypsin deficiency are genetic diseases characterized by endoplasmic reticulum (ER) stress with subsequent development of liver disease. Our aim was to estimate the frequency of hemochromatosis gene (HFE) mutant alleles (C282Y and H63D) and alpha-1 antitrypsin S/Z variants among Egyptian HCV cirrhotic patients and in hepatocellular carcinoma patients and to evaluate their effects on disease progression. HFE and alpha-1 antitrypsin polymorphisms were characterized in 200 Egyptian patients with HCV infection (100 patients complicated with cirrhosis, 100 patients with HCC) and 100 healthy subjects who had no history of any malignancy. The frequencies of HD genotype of H63D mutation were significantly increased in HCC patients compared to control group and to cirrhosis group. Also, the frequencies of DD genotype were significantly increased In HCC group compared to control group and to cirrhosis group. Our results suggested that Carriers of the D allele of H63D mutation were significantly more likely to develop HCC.     

动态分析沙鼠非酒精性脂肪肝病形成及生化影响

目的分析高脂饮食导致的沙鼠NAFLD疾病进展中脂质代谢、肝功能、抗氧化等方面的变化,探讨沙鼠NAFLD的形成机理。方法雄性沙鼠120只,随机分为对照组和模型组。对照组给予普通饲料,模型组高脂饮食建立NAFLD模型。分别于1、2、4、6、8、16周每组各处死10只动物,观察肝脏病理变化,计算肝指数,检测血清CHO、TG、LDL-C、HDL-C、GOP、GPT及肝组织的SOD、GSH-PX、CAT活性和FFA含量。结果模型组病理观察2周形成单纯性脂肪肝,6周动物门管区有轻度炎症,8周出现腺泡Ⅲ带局灶性窦周/细胞周纤维化,16周肝脏中度纤维化;模型组第1、2、4、6、8、16周时CHO、HDL-C、LDL-C及FAA波动性升高,但均高于同期对照组（P〈0.05,P〈0.01）,TG在1、2、4周高于同期对照组（P〈0.05,P〈0.01）;16周末GOT、GPT出现了显著性升高（P〈0.01）。抗氧化酶GSH-PX、CAT、SOD活性模型组在第8～16周显著性降低（P〈0.05,P〈0.01）。结论高脂饮食使沙鼠2周形成单纯性脂肪肝模型后,随饲喂时间延长,16周末可发展为中度肝纤维化。脂质代谢紊乱与氧化应激在沙鼠NAFLD进展中的发挥了不同的作用。     

When orthologs diverge between human and mouse

Despite the common assumption that orthologs usually share the same function, there have been various reports of divergence between orthologs, even among species as close as mammals. The comparison of mouse and human is of special interest, because mouse is often used as a model organism to understand human biology. We review the literature on evidence for divergence between human and mouse orthologous genes, and discuss it in the context of biomedical research.     

Effects of bone morphogenic protein 4 (BMP4) and its inhibitor,Noggin, on <Emphasis Type="Italic">in vitro</Emphasis>maturation and culture of bovine preimplantation embryos

Background  

BMP4 is a member of the transforming growth factor beta (TGFbeta) superfamily and Noggin is a potent BMP inhibitor that exerts its function by binding to BMPs preventing interactions with its receptors. The aim of this work was to investigate the role of BMP4 and Noggin, on oocytes in vitro maturation (m experiments) and embryos in vitro development (c experiments) of bovine.     

海藻酸微囊在细胞冷冻保存中的研究现状及应用

细胞的冷冻保存是细胞生物学实验中重要的实验技术.长期以来,人们使用冷冻保存液重悬细胞后进行冷冻储存,但是近年来,众多研究者发现传统冷冻方案往往会导致细胞活率大幅下降和细胞功能方面受损,从而很难满足生物医学、组织再生工程、细胞移植技术等高新技术的要求.所以研究者提出利用三维海藻酸微囊包埋细胞后再进行冷冻保存,从而在保证较高细胞活率的同时维持细胞的原有功能,有效的提高细胞的冷冻保存效率.本文概述了海藻酸微囊在细胞冷冻保存过程中的研究现状,同时对其应用进行了展望,以期为后续研究工作提供参考.