陆地棉干旱胁迫相关基因GhTrx的克隆及表达

采用RACE和RT-PCR技术,克隆了陆地棉干旱胁迫硫氧还蛋白基因,利用荧光定量PCR技术分析该基因在不同组织和不同时期的表达情况.结果表明,陆地棉硫氧还蛋白基因(GhTrx)的cDNA全长1 340 bp,其中ORF 864 bp,推测编码288个氨基酸.该基因编码蛋白与杨树、蓖麻、拟南芥的相似性分别为70%、72%和76%,系统发育树分析显示,GhTrx与蓖麻中该蛋白的亲缘关系最近.RT-PCR分析显示,GhTrx基因表达受干旱胁迫诱导,在干旱诱导下,该基因在抗旱材料中H177中上调表达,在根中的表达量明显高于叶.研究表明,GhTrx基因在干旱胁迫时根部进行大量表达,对抵御外界的干旱威胁起到关键作用,可能对提高陆地棉抗旱性方面具有一定的作用.     

灭幼脲对锈色粒肩天牛成虫生殖系统及取食产卵的影响

锈色粒肩天牛Apriona swainsoni Hope是我国重要绿化树种国槐Sophorajaponica的最严重的蛀干害虫,成虫期啃食国槐嫩枝补充营养。本研究用不同浓度灭幼脲处理的国槐枝条饲养锈色粒肩天牛成虫,结果表明,不同浓度的灭幼脲处理对该天牛雌、雄性成虫的取食量、产卵量的影响差异不显著,但对卵的孵化有显著的抑制作用,卵孵化抑制率最高可达76.32%。解剖发现浓度为0.20mg/g的灭幼脲能够干扰锈色粒肩天牛成虫内生殖系统的正常生长及发育,表现出一系列病变反应。     

Preparation of ethylene gas and comparison of ethylene responses induced by ethylene,ACC, and ethephon

Ethylene is a gaseous plant hormone used in many physiological studies examining its role in plant growth and development. However, ethylene gas may not be conveniently available to many laboratories for occasional use, and therefore several chemicals can be used as replacements. Here we report that the kinetics of the ethylene response induced by ethylene and two widely-used ethylene replacements are different. ACC failed to efficiently replace prolonged ethylene treatments, while the decomposition products of ethephon may cause non-specific responses and the efficiency of ethephon conversion to ethylene was relatively low. A cost-effective method to prepare ethylene gas was developed. Analyzed by gas chromatography, the chemically produced ethylene exhibited an identical chromatogram to that from the commercial source. Our synthetic ethylene gave the same dose-response curve in Arabidopsis as gaseous ethylene. Our study shows that the use of the ethylene gas is essential to experiments that are sensitive to treatment duration and dosage. When ACC and ethephon are used as replacements, caution should be taken in the experimental design. For laboratories that do not have an ethylene tank, ethylene gas can be easily prepared by a chemical approach without further purification.     

抗逆相关基因GmAREB转基因小麦的获得与鉴定

从大豆中克隆一个抗逆相关的bZIP类转录因子基因GmAREB,功能分析表明:GmAREB基因的过表达可以显著提高转基因拟南芥和烟草的抗旱、耐盐和耐寒性。为了获得抗逆转基因小麦,本研究利用玉米的Ubiqutin启动子控制GmAREB基因表达,构建了用于小麦转化的载体pSK-GmAREB。采用基因枪共转化法转化小麦品种郑147和济麦22。通过PCR检测共获得T0代的阳性植株70株,转化率为1.37%。其中,郑147阳性植株共31株,转化率为2.14%;济麦22阳性植株39株,转化率为1.08%。目前,已经获得T1代转基因株系18个,其中以郑147为受体的株系4个,以济麦22为受体的株系14个。对部分株系进行Southern blotting分析,进一步证实GmAREB基因已经整合到小麦基因组中。在低温胁迫条件下,3个以济麦22为受体的转基因株系体内脯氨酸的积累与受体小麦相比有显著增加,初步证明在小麦中过表达GmAREB基因,可以促进渗透调节物质脯氨酸的积累,可能有助于转基因小麦抗逆性的提高。本研究为进一步筛选抗逆转基因小麦新材料奠定了基础。     

中国凤蝶科昆虫地理分布的聚类分析

在对中国凤蝶科昆虫多样性分布统计的基础上,用特有性简约性方法构建中国凤蝶科昆虫的分布区分支图。结果表明,中国凤蝶在8大生物地理分布区中可分成6个聚类群,至少有5次大的隔离分化事件造成了目前我国凤蝶科昆虫的分布格局。分支图显示出东北区与蒙新区比其他分布区形成要早,华南区和西南区的凤蝶多样性最为丰富,推测其原因可能与生态环境等因素有关。     

可溶性细胞间粘附分子-1在新生儿缺氧缺血性脑病血清中的表达及临床意义

目的：探讨可溶性细胞间粘附分子-1（ICAM-1）在新生儿缺氧缺血性脑病（HIE）血清中的表达及其与病情严重程度的关系。方法：采用酶联免疫吸附双抗体夹心法（ELISA）检测45例HIE新生儿和50例健康新生儿血清中可溶性ICAM-1水平。结果：HIE组血清可溶性ICAM-1浓度为（159．25±25．62）ng／ml,对照组血清可溶性ICAM-1浓度为（53．35±12．42）ng／ml,两组相比较有显著性并差异（P〈0．05）;轻、中、重度HIE患儿血清可溶性ICAM-1浓度与对照组比较显著升高（P〈0．05）,在HIE各组中可溶性ICAM-1浓度为重度〉中度〉轻度,各组相比较有显著性差异（P〈0．05）;HIE患儿血清可溶性ICAM-1水平与临床分度呈正相关相关（r=0．652,P〈0．01）。结论：可溶性ICAM-1在HIE新生儿血清中呈高表达,可溶性ICAM-1的水平与病情严重程度密切相关。可溶性ICAM-1在新生儿缺氧缺血性脑损伤中起着重要作用：     

重金属污染的植物修复及相关分子机制

随着近代工业的发展,土壤重金属污染问题日益严重。重金属即使在极低浓度下仍然可以对人畜造成健康上的威胁,因此迫切需要有效的修复方法对土壤进行修复。生物修复,特别是植物修复目前已经成为重金属污染修复的重要手段之一,了解相关植物的重金属解毒和积累分子机制是提高修复效率、解决重金属污染问题的基础。文中以土壤修复方式为起点,结合植物吸收积累重金属以及解毒的相关分子机制研究,探讨了植物修复的发展现状以及趋势。     

桑枝多糖分离纯化及其免疫作用的初步研究

采用水提醇沉法从中药材桑枝(Ramulus mori)中分离纯化多糖,并建立桑枝多糖的含量测定方法;采用碳粒廓清法和二硝基氟苯诱导小鼠迟发型变态反应试验法,观察桑枝多糖对地塞米松所致免疫低下模型小鼠免疫功能的影响。结果显示,用改良的苯酚一硫酸法测得桑枝中多糖含量为5．5％,提取物桑枝多糖(RMPS)中的含量为56．6％。多次水溶醇沉后,桑枝多糖含量可达70％以上;桑枝多糖可显著提高免疫低下小鼠的吞噬指数α,增强网状内皮细胞的吞噬功能和小鼠迟发型变态反应能力,增强T细胞活性。     

单向纳入式人工胃底活瓣在食管-胃胸内吻合抗返流中的应用研究

目的:探讨单向纳入式人工胃底活瓣用于食管-胃胸内吻合抗返流患者的临床效果。方法:选择2017年3月-2018年3月入院治疗的食管中下段癌根治术患者70例,所有患者均在腹腔镜下完成全胸腹腔镜下食管-胃胸内吻合手术,术后采用胃肠吻合器完成食管胃右胸内吻合完成消化道重建。根据抗返流方法分为对照组(n=35例)和观察组(n=35例)。对照组术后包埋吻合口,观察组术后采用单向纳入式人工胃底活瓣,两组治疗完毕后对患者效果进行评估。记录并比较两组治疗后痊愈、全身衰竭死亡、吻合口瘘、返酸及吐苦水返流症状、烧心感的发生率;采用WHOQol-BREF生活量表对两组治疗前、治疗后生活质量进行比较。结果:观察组治疗后痊愈率显著高于对照组(71.43%vs. 42.86%,P0.05),全身衰竭死亡、吻合口瘘、返酸及吐苦水返流症状、烧心感发生率均明显低于对照组(P0.05)。两组治疗后生理健康、心理状态、社会关系、周围环境及独立能力评分均显著高于治疗前(P0.05),且观察组治疗后生理健康、心理状态、社会关系、周围环境及独立能力评分均高于对照组(P0.05)。结论:单向纳入式人工胃底活瓣用于食管中下段癌根治术患者能降低返流症状的发生率,能提高患者生活质量。     

Ozone pollution influences soil carbon and nitrogen sequestration and aggregate composition in paddy soils

Background and aims

Much attention has focused on the effects of tropospheric ozone (O₃) on terrestrial ecosystems and plant growth. Since O₃ pollution is currently an issue in China and many parts of the world, understanding the effects of elevated O₃ on soil carbon (C) and nitrogen (N) sequestration is essential for efforts to predict C and N cycles in terrestrial ecosystems under predicted increases in O₃. Thus the main objective of this study was to determine whether an increases in atmospheric O₃ concentration influenced soil organic C (SOC) and N sequestration.

Methods

A free-air O₃ enrichment (O₃-FACE) experiment was started in 2007 and used continuous O₃ exposure from March to November each year during crop growth stage in a rice (Oryza sativa L.)—wheat (Triticum aestivum L.) rotation field in the Jiangsu Province, China. We investigated differences in SOC and N and soil aggregate composition in both elevated and ambient O₃ conditions.

Results

Elevated atmospheric O₃ (18–80 nmol mol^?1 or 50 % above the ambient) decreased the SOC and N concentration in the 0–20 cm soil layer after 5 years. Elevated O₃ significantly decreased the SOC concentration by 17 % and 5.6 % in the 0–3 cm and the 10–20 cm layers, respectively. Elevated O₃ significantly decreased the N concentration by 8.2–27.8 % in three layers at the 20 cm depth. In addition, elevated O₃ influenced the formation and transformation of soil aggregates and the distribution of SOC and N in the aggregates across soil layer classes. Elevated O₃ significantly decreased the macro-sized aggregate fraction (16.8 %) and associated C and N (0.5 g kg^?1 and 0.32 g kg^?1, respectively), and significantly increased the silt+ clay-sized aggregate fraction (61 %) and associated C (1.7 g kg^?1) in the 0–3 cm layer. Elevated O₃ significantly decreased the macro-sized aggregate fraction (9.6 %) and associated C and N (1.4 g kg^?1 and 0.35 g kg^?1, respectively), and significantly increased the silt+ clay-sized aggregate fraction (41.8 %) and decreased the corresponding associated N (0.14 g kg^?1) in the 3–10 cm layer. Elevated O₃ did not significantly effect the formation and transformation of aggregates in the 10–20 cm layer, yet it did significantly increase the C concentration in the macro-sized fraction (1 g kg^?1) and decrease the N concentration in the macro- and micro-sized fractions (0.24 g kg^?1 and 0.16 g kg^?1, respectively).

Conclusion

Long-term exposure to elevated atmospheric O₃ negatively affected the physical structure of the soil and impaired soil C and N sequestration.