The Influence of Co-Suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid OxidaseⅠon the Expression of Fruit Ripening-Related and Pathogenesis-Related Protein Genes

The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase Ⅰ on the expression of fruit ripening-related and pathogenesis-related protein genes, and on the biosynthesis of endogenous ethylene and storage ability of fruits. Specific fragments of several fruit ripening-related and pathogenesis-related protein genes from tomato （Lycopersicon esculentum） were cloned, such as the l-aminocyclopropane-1-carboxylic acid oxidase 1 gene （LeAC01）, 1- aminocyclopropane-l-carboxylic acid oxidase 3 gene （LeAC03）, EIN3-binding F-box 1 gene （LeEBF1）, pathogenesis-related protein 1 gene （LePR1）, pathogenesis-related protein 5 gene （LePR5）, and pathogenesis-related protein osmotin precursor gene （LeNP24） by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato Ailsa Craig （AC＋＋） and the LeAC01 co-suppression tomatoes （V1187 and T4B）, respectively. At the same time, ethylene production measurement and storage experiment of tomato fruits were carded out. The hybridization results indicated that the expression of fruit ripening-related genes such as LeACO3 and LeEBF1, and pathogenesis-related protein genes such as LePR1, LePR5, and LeNP24, were reduced sharply, and the ethylene production in the fruits, wounded leaves decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in the transgenic tomato was suppressed. In the co-suppression tomatoes, the expression of fruit ripening-related and pathogenesis-related protein genes were restrained at different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.

急性髓系白血病GLIPR1基因甲基化及其表达

目的:检测GLIPR1基因在急性髓系白血病(AML)细胞株和AML患者骨髓细胞中的甲基化状态和表达水平,探讨其表达水平与启动子甲基化的关系。方法:以5株白血病细胞株,以及54例治疗前AML患者骨髓、48例急性淋巴细胞白血病(ALL)患者骨髓、40例慢性粒细胞白血病(CML)患者骨髓、35例对照骨髓和8例治疗后完全缓解AML患者骨髓为样本,采用RT-PCR检测GLIPR1mRNA表达水平,采用甲基化特异PCR(MS-PCR)方法检测GLIPR1基因甲基化状态,并对GLIPR1mRNA表达水平与其甲基化状态进行相关性分析。结果:GLIPR1基因在AML细胞株中的表达水平低于CML急性变细胞株和ALL细胞株,而前者甲基化水平高于后者。5-aza-2dC处理细胞后,GLIPR1基因在AML细胞株中的表达水平明显上调,而在CML急性变细胞株和ALL细胞株中的表达水平上调不明显。GLIPR1基因在AML骨髓中的表达水平(0.38±0.20)明显低于ALL骨髓(0.76±0.18)、CML骨髓(0.80±0.14)和对照骨髓(0.85±0.12),在完全缓解AML骨髓中的表达水平明显高于治疗前AML骨髓(0.78±0.13vs.0.36±0.20);而ALL和CML骨髓中的表达水平与对照骨髓比较无明显差异(P>0.05)。GLIPR1基因在AML骨髓的甲基化阳性率(81.5%)明显高于ALL骨髓(37.5%)、CML骨髓(27.5%)和对照骨髓(14.3%),在完全缓解AML骨髓中的甲基化阳性率明显低于治疗前骨髓(12.5%vs.75.0%);而在ALL和CML骨髓中的甲基化阳性率与对照骨髓比较无明显差异(P>0.05)。GLIPR1基因在AML骨髓中的表达水平与其甲基化呈负相关。结论:GLIPR1基因在AML中表达下调或缺失及启动子甲基化可能是导致GLIPR1基因表达沉默的原因,GLIPR1基因表达和甲基化水平对判断AML患者的疗效有一定意义。