Pollination-Induced Expression of Ethylene Biosynthetic Genes at Transcription Level in Orchid Flowers

The authors investigated pollination-induced ethylene production and expression patterns of genes encoding 1-aminocyclopropane-l-carboxylate (ACC) synthase and ACC oxidase in orchid flowers (Doritaenopsis hybrida Hort. ). Following pollination both ACC synthase and ACC oxidase mRNAs were detected in the different organs of flowers, and the patterns of both ACC synthase and ACC oxidase mRNA accumulation were similar, mRNA accumulation of ACC synthase mRNA was more organ-specific than that of ACC oxidase mRNA. However, ACC oxidase mRNAs were much more abundant than ACC synthase mRNAs in the flower organs.     

空气重金属元素在悬铃木叶中的亚细胞分布及其区隔化效应

以南京市常见行道树二球悬铃木为试材,研究了交通繁忙区和相对清洁区道路两边悬铃木叶内6种重金属元素的亚细胞分布及其区隔化效应.结果显示:交通污染区悬铃木叶内各亚细胞组分中Cr、Cu、Ni、Pb和Zn 5种重金属元素的含量均明显高于对照区,交通空气污染是影响其含量增加的主要原因之一.相对清洁区和交通污染区5种重金属元素在悬铃木叶片、叶柄的细胞壁组分中含量最高,胞外隔离系数和污染指数均大于0.900,细胞壁是大气重金属元素重要的吸滞器官,并对重金属有明显的阻隔效应;胞内细胞器对Pb和Cu的隔离系数和污染指数最大,细胞器双层膜能在一定程度上抵御重金属元素进入细胞内.悬铃木叶片和叶柄亚细胞组分的污染指数表现为胞质组分＞细胞壁组分＞细胞器组分,即包括液泡液在内的胞质组分是囤积重金属元素的场所.研究表明,悬铃木叶片、叶柄各亚细胞组分对重金属均有不同程度的累积能力,叶内胞质组分的囤积作用以及细胞壁、质膜与细胞器双层膜的区隔化作用可能是悬铃木叶解除重金属元素毒害的重要原因.     

模拟酸雨和镉复合处理对秃瓣杜英生长和荧光参数的影响

通过盆栽试验研究了模拟酸雨(pH 3.0和pH 5.6)和镉(Cd 50和Cd 100)复合污染以及对照处理(CK)对秃瓣杜英(Elaeocarpus glabripetalus)的生长和生理指标的影响。结果表明:单独的酸雨处理显著增加了植株总生物量的积累,促进了根和叶片生物量的分配,降低了茎干生物量的分配,且显著降低了叶片中的镉含量。单独镉处理下,Cd 50显著增加了植株生物量的积累,促进了根和叶片生物量的分配,Cd 100虽抑制了植株生物量的积累,但生物量分配几乎不受影响。复合处理促进了植株根和叶片生物量的分配,降低茎干生物量分配,且降低了根冠比,其中pH 5.6+Cd 100显著促进了植株生物量的积累。所有处理的荧光参数与对照无显著差异,说明未对植株的PSⅡ反应中心产生显著影响。镉在植株体内的积累为:根茎叶。酸雨强度和镉浓度的交互作用对生物量,镉含量和F0影响显著。因此,秃瓣杜英对酸雨和镉的复合污染有较强的耐受能力。     

超抗原SEA与抗黑色素瘤ScFv融合基因的构建及表达

采用酶切连接和重叠PCR连接两种方法将抗黑色素瘤单链抗体基因和去除N端信号肽的金黄色葡萄球菌肠毒素A基因进行融合,并将融合基因克隆于pET28a表达载体上,转化大肠杆菌BL21(DE3)。用NiNTA系统对表达产物进行分离、纯化。MTT法检测融合蛋白对黑色素瘤细胞的体外抑制率。结果表明6HisScFvSEA融合蛋白可在E.coli BL21(DE3)中稳定表达,表达量占菌体蛋白的30%,主要以包涵体的形式存在。融合蛋白可通过激活效应细胞对表达相关抗原的黑色素瘤细胞发挥抑制作用。     

PHI-1 induced enhancement of myosin phosphorylation in chicken smooth muscle

Herein, we provide evidence that in chicken smooth muscle, G-protein stimulation by a Rho-kinase pathway leads to an increase in myosin light chain phosphorylation. Additionally, G-protein stimulation did not increase MYPT1 phosphorylation at Thr695 or Thr850, and CPI-17, was not expressed in chicken smooth muscle. However, PHI-1 was present in chicken smooth muscle tissues. Both agonist and GTP(gamma)S stimulation result in an increase in PHI-1 phosphorylation, which is inhibited by inhibitors to both Rho-kinase (Y-27632) and (PKC) GF109203x. These data suggest that PHI-1 may act as a CPI-17 analog in chicken smooth muscle and inhibit myosin phosphatase activity during G-protein stimulation to produce Ca2+ sensitization.     

A chemically induced new pea (Pisum sativum) mutant SGECdt with increased tolerance to, and accumulation of, cadmium

BACKGROUND AND AIMS: To date, there are no crop mutants described in the literature that display both Cd accumulation and tolerance. In the present study a unique pea (Pisum sativum) mutant SGECd(t) with increased Cd tolerance and accumulation was isolated and characterized. METHODS: Ethylmethane sulfonate mutagenesis of the pea line SGE was used to obtain the mutant. Screening for Cd-tolerant seedlings in the M2 generation was performed using hydroponics in the presence of 6 microm CdCl2. Hybridological analysis was used to identify the inheritance of the mutant phenotype. Several physiological and biochemical characteristics of SGECd(t) were studied in hydroponic experiments in the presence of 3 microm CdCl2, and elemental analysis was conducted. KEY RESULTS: The mutant SGECd(t) was characterized as having a monogenic inheritance and a recessive phenotype. It showed increased Cd concentrations in roots and shoots but no obvious morphological defects, demonstrating its capability to cope well with increased Cd levels in its tissues. The enhanced Cd accumulation in the mutant was accompanied by maintenance of homeostasis of shoot Ca, Mg, Zn and Mn contents, and root Ca and Mg contents. Through the application of La(+3) and the exclusion of Ca from the nutrient solution, maintenance of nutrient homeostasis in Cd-stressed SGECd(t) was shown to contribute to the increased Cd tolerance. Control plants of the mutant (i.e. no Cd treatment) had elevated concentrations of glutathione (GSH) in the roots. Through measurements of chitinase and guaiacol-dependent peroxidase activities, as well as proline and non-protein thiol (NPT) levels, it was shown that there were lower levels of Cd stress both in roots and shoots of SGECd(t). Accumulation of phytochelatins [(PCcalculated) = (NPT)-(GSH)] could be excluded as a cause of the increased Cd tolerance in the mutant. CONCLUSIONS: The SGECd(t) mutant represents a novel and unique model to study adaptation of plants to toxic heavy metal concentrations.     

生物扰动对沉积物中污染物环境行为的影响研究进展

生物扰动由于显著改变沉积物结构和性质,进而影响沉积物中污染物的环境行为。综述生物扰动对沉积物中氮、磷、重金属和疏水性有机污染物环境行为的影响。生物扰动促进这些污染物从沉积物向水体释放。生物扰动还对不同的污染物产生其它不同的影响。对于氮,生物扰动还影响其硝化与反硝化作用;对于磷,生物扰动不仅改变其化学形态,还提高有机磷降解。对于重金属,生物扰动还能改变其在沉积物中的分布及化学形态。对于疏水性有机污染物,生物扰动主要增强生物富集和代谢,以及提高生物降解。     

Enhanced (Na+K)-ATPase Activity and Expression in Mouse Brain after Chronic Ethanol Administration

It is the general hypothesis that the primary mode of action of ethanol is the alteration of membrane structure and function including the conformation of receptors and ion channels essential for neurotransmission and signal transduction. However, the issue of whether ethanol affects (Na+K)-ATPase under physiological conditions remains unsettled. In this study, adult mice were treated with a daily dose of 5 g/kg of ethanol for 28 days. The RNA was isolated from brain and the (Na+K)-ATPase mRNA level was determined using Northern blot analysis. We have found an increased expression of (Na+K)-ATPase -subunit in the chronically treated alcohol group as compared with that of controls. This result was further substantiated by increased protein phosphorylation as well as increased specific activity of this enzyme in the synaptosomal plasma membrane after chronic ethanol administration. Thus we have demonstrated that ethanol may directly affect (Na+K)-ATPase in vivo, leading to the increased synthesis of this enzyme through adaptive mechanisms.     

Genetic association of the gene encoding RPGRIP1L with susceptibility to vascular dementia

A previous genome-wide association study (GWAS) failed to discover any nucleotide sequence variant associated with susceptibility to vascular dementia (VaD) and remained a problem of false negatives produced by a low statistical power. The current study was conducted to identify such potential false negatives and to provide comprehensive evidence for the most plausible predisposing genetic factor using large-scale Korean cohorts. We identified the gene encoding retinitis pigmentosa GTPase regulator-interacting protein 1-like (RPGRIP1L) with multiple nucleotide variants associated with susceptibility to VaD by a modest significant threshold (P<10(-4)). Genetic associations were intensively examined with its sequence variants using 207 VaD patients and 207 age- and gender-matched control subjects. Genetic association analysis with dense variants in the region associated with VaD revealed 3 variants (P<0.0017) in strong linkage. Further analysis with VaD-related phenotypes using Korean Association REsource (KARE) cohort data showed that the region of the gene was associated with alanine aminotransferase (ALT), aspartate aminotransferase (AST), and blood pressure (BP) (P<7.6×10(-4)). The current study provided the first evidence of the association between RPGRIP1L gene and susceptibility of VaD. Functional studies are needed to understand underlying biological mechanism of the genetic association.