فهرست مطالب رزگار سیدرحمانی

Artemisia genus from Asteraceae family has 34 species in Iran with valuable medicinal compounds. The most important use of Artemisia has been the treatment of malaria in traditional Chinese medicine. In addition to artemisinin، it produces also other secondary metabolites such as polyphenols، terpenes، phytosterols and alkaloids. MEP (2-C-methyl-D-erythritol-4-phosphate pathway) pathway is a chloroplastic pathway by which monoterpenes are produced. It exists only in photosynthesis plants and some bacteria. In this study، monoterpene compounds produced by MEP pathway in three kinds of tissues including leaf، bud and flower were compared with the expression of three genes in the pathway (DXS، DXR، HDR). Monoterpene compounds were measured by GC/MS and genes expression was evaluated by Real-Time PCR. Six Monoterpene compounds including α-pinene، Camphene، β-Myrcene، 1،8-Cineole، Artemisia ketone and Camphor detected by GC/MS analysis on leaf، bud and flower extracts، with 60. 8، 54 and 78. 76 percent of extract، respectively. Artemisia ketone and Camphor had higher levels compared to other compounds. DXS expression in leaves was three times higher than that of buds and flowers. DXR showed the highest expression in flowers. Expression of HDR in leaves or buds was three times higher than that of flowers. Comparing the results of gene expression and GC/MS suggested that DXR plays more important role in producing monoterpene compounds and might be a candidate gene for genetic engineering.

Since plants are living organisms and cannot escape from biotic and abiotic stresses، they require a regular signaling network for regulation of cellular processes and homeostasis. Reactive oxygen species (ROS) are toxic molecules that can react with vital molecules such as proteins، nucleic acids، lipids، and carbohydrates and cause damage to them. ROS with their unique properties can act as signal molecules that play a role in plant responses. In plants، the signaling role of ROS and cell protection from their toxic effects require a regulatory network and defense systems respectively so that the amount of these factors determine the degree of tolerance. ROS is produced in different organelles like chloroplast، mitochondria، peroxisomes and apoplastic space. The levels of them are regulated by different detoxification mechanisms. ROS is involved in different signaling pathways like MAPK and calcium، and change gene expression patterns in order to respond to stress via specific protein oxidation and affecting transcription factors. In this review، signaling pathway، production، function، and degradation mechanisms of ROS and the effect of ROSs on cell processes like glutathionylation and protein folding under stress conditions are described.