chlorophyll-b and methyl-jasmonate

In the methyl-D-erythritol-4-phosphate (MEP) pathway, 1-deoxy-D-xylose-5-phosphate synthase (DXS) is considered the key enzyme for the biosynthesis of terpenoids. In this study,

Topics: Acetates; Chlorophyll; Chlorophyll A; Computational Biology; Cyclopentanes; Escherichia coli; Gene Expression Profiling; Nicotiana; Oxylipins; Pentosephosphates; Pigmentation; Pinus; Plant Leaves; Plant Stems; Promoter Regions, Genetic; Recombinant Proteins; Salicylic Acid; Terpenes; Transferases; Xylose

The plastidial methylerythritol phosphate(MEP) pathway provides 5-carbon precursors to the biosynthesis of isoprenoid (including artemisinin). 2-C-Methyl-D-erythritol-4-phosphate cytidylyltransferase (MCT) is the third enzyme of the MEP pathway, which catalyzes 2-C-methyl-D-erythritol-4-phosphate to form 4-(cytidine 5’-diphospho)-2-C-methyl-D-erythritol. The full-length MCT cDNA sequence (AaMCT) was cloned and characterized for the first time from Artemisia annua L. Analysis of tissue expression pattern revealed that AaMCT was highly expressed in glandular secretory trichome and poorly expressed in leaf, flower, root and stem. AaMCT was found to be a methyl jasmonate (Me JA)-induced genes, the expression of AaMCT was significantly increased after MeJA treatment. Subcellular localization indicated that the GFP protein fused with AaMCT was targeted specifically in chloroplasts. The transgenic plants of Arabidopsis thaliana with AaMCT overexpression exhibited a significantly increase in the content of chlorophyll a, chlorophyll b and carotenoids, demonstrating that AaMCT kinase plays an influential role in isoprenoid biosynthesis.

Topics: Acetates; Arabidopsis; Artemisia annua; Artemisinins; Carotenoids; Chlorophyll; Chlorophyll A; Cloning, Molecular; Cyclopentanes; DNA, Complementary; Gene Expression Regulation, Plant; Nucleotidyltransferases; Oxylipins; Plant Proteins; Plants, Genetically Modified

Methyl jasmonate (MeJA) elicits protective effects as form of plant response to abiotic stress. However, related studies on plant response to metal stress are insufficient. This study aimed to examine the effects of MeJA on growth and physiological responses of Capsicum frutescens seedlings exposed to cadmium (Cd) stress. The study was performed in an artificial climate chamber. Results showed that 50 mg L⁻¹ Cd significantly impaired the growth of the seedlings by increasing leaf MDA content and decreasing chlorophyll b. These effects were significantly mitigated by MeJA at low concentrations (0.1 µmol L⁻¹). The dry weights of different plant parts, chlorophyll content, and leaf catalase and ascorbate peroxidase activities were increased by a low MeJA concentration (0.1 µmol L⁻¹) but were decreased by a high MeJA concentration (1000 µmol L⁻¹). Significant increases in endogenous jasmonic acid were observed at 48 h after the samples were treated with Cd and 0.1 µmol L⁻¹ MeJA. These results suggested that low exogenous MeJA concentrations exhibited protective effects on the growth and physiology of C. frutescens seedlings under Cd stress.

Topics: Acetates; Ascorbate Peroxidases; Cadmium; Capsicum; Catalase; Chlorophyll; Cyclopentanes; Hydrogen Peroxide; Lipid Peroxidation; Oxylipins; Plant Leaves; Seedlings; Soil Pollutants; Stress, Physiological