番茄匍柄霉叶斑病拮抗细菌的筛选与鉴定

应用平板对峙法从连作多年的番茄根际土样中筛选得到对番茄匍柄霉叶斑病具有较强拮抗活性的细菌菌株ZF161,该菌株对番茄匍柄霉的平板抑制率达到70.51%。离体叶片试验显示,菌株ZF161对番茄匍柄霉叶斑病防治效果达到69.83%。通过菌落形态观察、生理生化特性、Biolog测定和多基因系统发育树综合分析,鉴定菌株ZF161为枯草芽孢杆菌(Bacillussubtilis)。番茄盆栽试验结果表明,菌株ZF161对番茄匍柄霉叶斑病的防治效果达到63.27%。进一步平板对峙抑菌谱试验结果显示,菌株ZF161对其他7种病原真菌也具有较好的抑制效果。上述结果说明,菌株ZF161对番茄匍柄霉叶斑病具有良好的防治效果,且对多种病原真菌也具有抑制作用,具有开发应用的潜力。     

枯草芽孢杆菌NBF809防治番茄棒孢叶斑病研究

采用平板对峙结合显微观察确定枯草芽孢杆菌NBF809菌株对多主棒孢的抑菌活性,采用活体盆栽试验研究其对番茄棒孢叶斑病的防治效果。结果表明,在平板对峙条件下NBF809菌株对多主棒孢具有良好的抑菌活性,显微镜下观察到菌丝发生扭曲、肿胀和变形;盆栽试验结果表明NBF809菌株对番茄棒孢叶斑病的防治效果达到73.26%。聚合酶链式反应用于检测NBF809菌株的抗菌素生物合成基因,扩增到bac D、itu C、itu D、mrs M和myc C 5个基因,涉及Bacilysin、Iturin、Mersacidin和Mycosubtilin 4种抗菌素的合成。     

赤峰地区番茄灰叶斑病病原菌的鉴定

以番茄灰叶斑病为研究对象,采用形态学鉴定、致病性检测和分子生物学等方法,研究了赤峰地区番茄灰叶斑病的病原菌种类,以期为该病害的防治提供参考依据。结果表明:病原菌(ZTWYF16081515)分生孢子淡褐色,长方形至圆柱形,大小为(21.4~71.9)μm×(10.5~27.3)μm。分离菌株喷雾接种,7d后番茄叶片上形成典型的番茄灰叶斑病病斑。核糖体RNA基因内转录间隔区(ITS)和gpd区的PCR产物经测序后进行BLAST分析,均表明该菌与茄匍柄霉S.solani的ITS和gpd序列100%相同,确定该病原为茄匍柄霉S.solani。     

菠菜匍柄霉叶斑病的诊断及防治

<正>菠菜匍柄霉叶斑病是由匍柄霉属病原菌引起的一种真菌病害。早在2001年Koike等报道了匍柄霉(Stemphylium botryosum)可以引起菠菜叶斑病。2005年,美国亚利桑那州也相继报道了由匍柄霉(S.botryosum)引起的菠菜病害。我们研究组于2009年在甘肃省兰州市采集菠菜叶斑病样本后,分离病原菌,根据形态学特征、致病性试验及分子测序,鉴定其病原菌为匍柄霉属一个新种,即菠菜     

番茄早疫病拮抗内生细菌的分离及防病作用

利用稀释分离法,从健康的番茄植株中分离得到11个细菌菌株。通过平板对峙试验筛选出对番茄早疫病菌抑菌效果最好的Fb9菌株,抑菌率为70.81%。Fb9菌株对番茄的生长具有促进作用,对番茄早疫病的室内盆栽防治效果为63.7%。     

李宝聚博士诊病手记（三十）番茄匍柄霉叶斑病（灰叶斑病）的诊断与防治

匍柄霉属（Stemphylium）真菌可以引起多种蔬菜
病害,包括番茄、莴苣、辣椒、甘蓝等。美国、以色列、新
西兰等地均报道过由匍柄霉引起的番茄叶斑病,在我
国也有类似报道,多称之为番茄灰叶斑病（刘安敏,
2002;李宝聚,2009）。我们在前几年的蔬菜病害调查
过程中发现,北京大兴、辽宁海城、河北廊坊、保定以
及山东寿光等地都有该病的发生,但当时并未严重影
响番茄的产量。2009～2010 年的蔬菜病害调查过程
中我们发现,番茄匍柄霉叶斑病由一种不常见病害逐
渐发展为严重发生的病害,在海南省海口市西秀镇龙
头村、海南省海口市灵山镇大昌村、山东寿光洛城镇
黄家尧水村、山东寿光田柳镇陈马村等地都发现了番
茄匍柄霉叶斑病的严重危害。尤其是在山东寿光田柳
镇陈马村,番茄于1 月份定植后开始零星发生匍柄霉
叶斑病,到了3 月份番茄大约1.7 m 高时,温室中绝
大多数的番茄都发生了匍柄霉叶斑病,尤其是连阴天
湿度大,温度忽高忽低时,该病发生更为肆虐,严重影
响了番茄的产量,给农民带来了巨大的损失。现对番
茄匍柄霉叶斑病的症状、病原菌、发生规律、防治方法
等进行简单描述,方便广大农民认识该病,并进行及
时防治。     

李宝聚博士诊病手记（八十） 菠菜匍柄霉叶斑病的诊断及防治

菠菜匍柄霉叶斑病是由匍柄霉属病原菌引起的一种真菌病害。早在2001 年Koike 等报道了匍柄
霉（Stemphylium botryosum）可以引起菠菜叶斑病。2005 年,美国亚利桑那州也相继报道了由匍柄霉
（S. botryosum）引起的菠菜病害。我们研究组于2009 年在甘肃省兰州市采集菠菜叶斑病样本后,
分离病原菌,根据形态学特征、致病性试验及分子测序,鉴定其病原菌为匍柄霉属一个新种,即菠菜匍柄霉（Stemphylium spinaciae B. J. Li, Y. F. Zhou & Y.
L. Guo sp. nov. ）（Zhou et al.,2011）。近年来,随着菠菜需求量的不断上升,其种植面积也在不断的加
大,菠菜匍柄霉叶斑病已逐渐成为危害菠菜生产的一个主要病害。该病害在我国华北及西北地区发生
较为严重,给当地的菜农造成了一定的经济损失。     

番茄灰霉病生防菌株TL1的分离、鉴定及其生防能力分析

为了筛选对番茄灰霉病菌(Botrytis cinerea)具有拮抗作用的菌株,通过平板对峙法从西藏高原土壤中分离筛选到一株具有较好拮抗作用的菌株TL1。形态学观察、生理生化分析以及分子生物学鉴定结果表明,该菌株为马氏类芽孢杆菌(Paenibacillus maysiensis),并具有固氮和溶磷作用。TL1在平板上能显著抑制灰霉病菌菌丝生长,抑菌率为74.32%,且该菌产生的挥发性物质呈现显著抑菌活性。进一步平板抑菌试验表明,TL1菌株对褐斑病菌等6种病原真菌均具有显著抑菌活性,其中对烟草赤星病菌(Alternaria alternata)的抑制率最高(73.48%),对黄瓜褐斑病菌(Corynespora cassiicola)的抑制率最低(57.37%)。TL1菌株能够在番茄果实上定殖并抑制由灰霉病菌引起的腐烂,且可以显著提高番茄种子的萌发率以及促进番茄幼苗生长。     

死亡谷芽孢杆菌NBIF-001防治灰霉病研究

为明确死亡谷芽孢杆菌NBIF-001菌株对灰霉病的防治效果,采用平板对峙结合显微观察确定其对灰霉病菌的抑菌活性,并采用离体组织试验研究其对黄瓜叶部灰霉病及贮藏期番茄果实灰霉病的防治效果。结果表明,在平板对峙条件下NBIF-001对灰葡萄孢具有良好的抑菌活性,显微镜下观察到菌丝发生扭曲、肿胀和变形;离体试验结果表明NBIF-001对灰霉病具有良好的生防效果,对黄瓜叶片灰霉病和番茄果实灰霉病的防效分别达到85.91%和72.52%。     

枇杷内生木霉P3.9菌株抗菌谱研究

以枇杷内生木霉P3.9菌株及枇杷根腐病病菌Pestalotiopsis sp.、康乃馨根腐病菌Fusariumsp.、仙客来根腐病菌Fusariumsp.、万寿菊叶斑病病菌Alternariasp.、辣椒黑斑病病菌Alternariasp.、辣椒黄萎病病菌Verticillium dahliae 6种供试病原真菌为试材,采用对峙培养法,将P3.9菌株与各病原菌进行对峙培养,测定其对各病原真菌的抑制作用。结果表明:P3.9菌株对6种供试病原真菌均有不同程度的抑制作用,抑制率分别为80.6%、67.6%、73.1%、77.5%、82.0%和82.7%,抑制率均在60%以上,说明P3.9菌株抗菌谱广泛,表现出良好的开发应用前景,为有效可持续防控上述各病害提供参考依据及生防菌种资源。     

Blocking autophagy magnifies MK-2206-induced DNA damage in SGC-7901 cells

AIM: To investigate the effect of MK-2206, an inhibitor of protein kinase B(Akt), on the DNA damage of SGC-7901 cells.METHODS: SGC-7901 cells were treated with different concentrations of MK-2206, and phosphorylated histone H2AX(γ-H2AX) foci formation was detected by immunofluorescence staining. Western blot analysis was used to exam the levels of DNA damage-related protein. The expression of LC3-Ⅱ was determined to evaluate the change of autophagy.RESULTS: MK-2206 treatment increased the formation of γ-H2AX foci and histone H2AX phosphorylation in the SGC-7901 cells. The levels of DNA damage response protein were also increased. In addition, MK-2206-treated SGC-7901 cells increased the expression of LC3-II, a hallmark of autophagy. Inhibition of autophagy significantly enhanced MK-2206-mediated histone H2AX phosphorylation.CONCLUSION: MK-2206 induces DNA damage and autophagy in SGC-7901 cells. Blocking autophagy potentiates the response of MK-2206-induced DNA damage.     

GDC-0032 inhibits cell viability and induces DNA damage in U251 human glioma cells

AIM: To investigate the effect of phosphatidylinostiol 3-kinase (PI3K) inhibitor GDC-0032 on cell viability, cell cycle and DNA damage in human glioma U251 cells. METHODS: The cell viability was analyzed by MTT assay. The cell cycle distribution of U251 cells was examined by flow cytometry. The protein expression was examined by Western blot. The expression and localization of γ-H2AX were determined by laser-scanning confocal microscopy. RESULTS: GDC-0032 inhibited the cell viability in a dose-dependent manner. U251 cells showed G₁ phase arrest accompanied with upregulation of p27 protein after exposure to GDC-0032, while the expression of cell division cycle protein 2 (Cdc2) was inhibited. GDC-0032 treatment increased the formation of γ-H2AX foci and histone H2AX phosphorylation in the U251 cells. In addition, GDC-0032 upregulated the phosphorylation levels of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), in the glioma cells, while the expression of survivin was inhibited. CONCLUSION: GDC-0032 inhibits U251 cell growth by inhibition of cell viability and cell cycle progression. GDC-0032 also induces DNA damage of U251 cells. The anticancer activity of GDC-0032 is associated with increasing the activity of ERK and JNK and downregulating the expression of survivin.     

The adaptive response of low dose sodium nitrite pretreatment on cultured CHL cells to DNA damage caused by high dose sodium nitrite

AIM: To study if low dose NaNO₂ can induce the adaptive response of cultured Chinese hamster lung cells（CHL cells）to DNA damage. METHODS: Single cell gel electrophoresis technique was used to detect the DNA damage in CHL cells exposed to NaNO₂ at different concentrations. CHL cells were pretreated with NaNO₂ of concentrations of 0.01 mg/L, 0.1 mg/L and 1 mg/L respectively. And the adaptive response to the toxicity of 1g/L NaNO₂ was observed. The activity of polyADP- ribose polymerase (PARP-1) of CHL cells was inhibited with 3-aminobenzamide(3AB) before or after pretreated with low dose of NaNO₂. And the changes of the adaptive response were observed. RESULTS: The rate of tailing cells was 7.87% when the cells were exposed to 1 g/L NaNO₂ without pretreatment with low dose NaNO₂. An extremely remarkable statistics significance (P＜0.01) was observed when compared the difference to control group. NaNO₂ of 0.01 mg/L and 0.1 mg/L could induce the adaptive response of cultured CHL cells to DNA damage caused by 1 g/L NaNO₂. The rate of tailing cells was 3.55% and 1.06％ respectively, which was much lower than that of no-pretreatment group(P＜0.05；P＜0.01). But the rate of tailing cells was 6.09% when the cells were exposed to 1 g/L NaNO₂ with pretreatment of 1 mg /L NaNO₂, which had no significant difference compared with the rate of tailing cells in control group (P＞0.05). The adaptive response could be blocked when the activity of PARP-1 was inhibited with 3AB before the low dose pretreatment, but could not be blocked when the activity of PARP-1 was inhibited after low dose NaNO₂ pretreatment 6 h. CONCLUSION: NaNO₂ of concentration that equals to or lowers than 0.1 mg/L can induce the adaptive response of cultured CHL cells to DNA damage caused by high dose NaNO₂ through PARP-1 activation. And the dose of NaNO2 that can induce adaptive response might not cause the DNA damage.     

草菇丝/苏氨酸蛋白激酶同源基因的克隆及序列分析

根据担子菌丝/苏氨酸蛋白激酶同源基因编码的氨基酸序列设计两对简并引物,通过巢式简并PCR方法获得草菇(Volvariella volvacea)丝/苏氨酸蛋白激酶同源基因(vv-stpk1)的保守片段,然后通过基因组步行的方法获得了vv-stpk1全长序列。vv-stpk1全长为2 003 bp,含有8个内含子,长度分别为72、57、53、54、45、50、55和48 bp,可编码522个氨基酸残基的多肽。推定的氨基酸序列与玉米黑粉菌(Ustilagomaydis)、木糖发酵酵母(Pichia stipitis)、新型隐球菌(Cryptococcus neoformans)中与细胞形态发生相关的丝/苏氨酸蛋白激酶Orb6的相似性分别为81%、77%和76%,对VV-STPK1蛋白的系统发生学分析的结果表明,VV-STPK1与Orb6同源蛋白聚在同一进化枝上,这些数据都支持VV-STPK1蛋白为与细胞形态发生相关同源蛋白的推定。     

CUDC-907 induces DNA damage and autophagy in glioma cells

AIM:To investigate the effect of CUDC-907, a dual histone deacetylase (HDAC) and phosphatidylinositol 3-kinase (PI3K) inhibitor, on the DNA damage, cell cycle distribution and autophagy in human glioma U251 cells. METHODS:U251 cells were treated with CUDC-907 of different concentrations, and the cell viability was detected by MTT assay. The quantitative γ-H2AX foci were determined by laser scanning confocal microscopy. The cell cycle distribution of U251 cells was examined by flow cytometry. The protein expression was determined by Western blot analysis. RESULTS:CUDC-907 inhibited the cell viability and the phosphorylation of Akt and p70 ribosomal protein S6 kinase (p70s6K) in the U251 cells (P<0.05). In CUDC-907-treated cells, the number of γ-H2AX foci and protein expression of γ-H2AX were increased significantly (P<0.05). CUDC-907 also induced cell arrest in the G₂/M phase by up-regulating the expression of p21, and inhibiting the protein level of cyclin B1 and the phosphorylation of cell division cycle protein 2 (Cdc2). In addition, CUDC-907 triggered cell autophagy, and inhibition of autophagy increased CUDC-907-induced DNA damage of U251 cells. CONCLUSION:CUDC-907 significantly inhibits PI3K/Akt signaling pathway, induces DNA damage and arrests cell cycle in G₂/M phase. Blockage of autophagy promotes CUDC-907-induced DNA damage of U251 cells.     

APE/Ref-1 protein and ischemia/reperfusion injury of neurons in the brain

Cerebral ischemia and the aftermath of reperfusion form a hypoxic/hyperoxic sequence of events that can trigger DNA damage in neurons of central nervous system. Neuronal apoptosis will happen without immediate DNA repair. APE/Ref-1 is a multifunctional protein involoved in DNA base excision repair pathway and in redox reguiation of DNA-binding activity of AP-1 family members, which may play an important role in protection of postischemic neuronal damage.     

Advance in function of deubiquitination enzyme BRCC36

The protein of BRCC36 is a kind of enzyme specifically hydrolyzing K63-linked poly-ubiquitin chain and widely found in a variety of eukaryotic cells. BRCC36 recognizes diverse substrate proteins, and participates in various kinds of pathophysiological responses such as DNA damage repair, cell signal transduction and cell cycle control. It plays an important role in the process of cancer, angiogenesis and cardiac injury. This review discusses the progress in the investigation on BRCC36 protein to provide the necessary information for searching new therapeutic targets of many diseases.     

Study on mutation of mitochondrial gene from rat breast cancer

AIM: To know the variations of the cytochrome b gene in cancer tissue, paracarinoma tissue and normal tissue and to inquire into the relationship between mutations of mitochondrial genome and carcinogenesis. METHODS: Cellular total DNA was extracted.The cytochrome b genes of three tissues were amplifyed with polymerase chain reaction(PCR). PCR products were analysed by DNA auto-sequencing method. RESULTS: The cytochrome b gene of cancer tissue had the C to G mutation at nt 14931, the C to G mutation at nt 15004 and the T to C mutation at nt15435,respectively. The cytochrome b gene of paracarinoma tissue had the A to C mutation at nt 15436. The cytochrome b gene of normal tissue had not mutation. CONCLUSION:Mitochondrial DNA mutations could be the endogenous factors that induce nuclear genome mutation. It could promoto carcinogenesis. The paracarinoma tissue was abnormal in DNA molecular level.     

Effect of MCPH1 on irradiation induced DNA damage in esophageal cancer cells

AIM: To discover the effect of MCPH1 on the DNA damage induced by ionizing radiation in esophageal cancer cells. METHODS: ECA109 cancer cells were radiated at dose of 8 Gy. The nuclear foci of relevant factors were detected 1 h after irradiation in the ECA109 cells after silence of MDC 1 gene. A cell line was established that was stable low expression of MCPH 1 . The nuclear foci induced by ionizing radiation after silence of MCPH 1 were determined. RESULTS: The MCPH1 gene silenced ECA109 cell line was successfully constructed. A strong relationship between MDC1, MCPH1 and γ-H2AX was observed 1 h after 8 Gy irradiation. Silence of MDC 1 did not affect the nuclear foci formation of γ-H2AX and MCPH1. The nuclear foci of MDC1 but not γ-H2AX significantly reduced after silencing of MCPH 1 . CONCLUSION: MCPH1 is located in the downstream of H2AX and upstream formation of MDC1, and regulates the nuclear foci formation of MDC1 during DNA damage response.     

Progress in epigenetic study of clear cell renal cell carcinoma

The epigenetic changes of clear cell renal cell carcinoma (ccRCC) are considered to be the main molecular mechanisms of its pathogenesis, including DNA methylation, histone modification, microRNA change, and so on. DNA methyltransferases (DNMTs) catalyze the occurrence of DNA methylation. DNA methylation changes are manifested in the overall low methylation of the genome and the high methylation of specific sites, which were involved in the development of ccRCC by affecting the expression of tumor suppressor genes. Due to histone-modified enzyme involvement, histone modification is shown as possible genetic reversal. MicroRNA plays an important role in the abnormal expression of ccRCC genes. With the studies of epigenetic mechanism and molecular pathology, it is important to explore the mechanisms and to seek effective early diagnosis, treatment and prognosis intervention of ccRCC.