Coordinated activation of metabolic pathways for antioxidants and defence compounds by jasmonates an

Coordinated - The Plant Journal(2005 44 653668 doi 10.1111/j.1365-313X.2005.02560.x Coordinated activation of metabolic pathways for antioxidants

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Coordinated activation of metabolic pathways for antioxidants and defence compounds by jasmonates and their roles in stress tolerance in Arabidopsis Yuko Sasaki-Sekimoto 1,* , Nozomi Taki 1 , Takeshi Obayashi 1 , Mitsuko Aono 2 , Fuminori Matsumoto 1 , Nozomu Sakurai 3 , Hideyuki Suzuki 3 , Masami Yokota Hirai 4,5,6 , Masaaki Noji 4 , Kazuki Saito 4,5,6 , Tatsuru Masuda 1,† , Ken-ichiro Takamiya 1 , Daisuke Shibata 3 and Hiroyuki Ohta 1,7 1 Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, 4259 B-14 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226–8501, Japan, 2 National Institute for Environmental Studies, Environmental Biology Division, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan, 3 Kazusa DNA Research Institute, PM NEDO laboratory, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba, 292-0818, Japan, 4 Chiba University, Graduate School of Pharmaceutical Sciences, 1-33, Yayoi-cho, Inage-ku, Chiba, Chiba, 263-8522, Japan, 5 CREST, JST (Japan Science and Technology Corporation), Japan, 6 RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan, and 7 Tokyo Institute of Technology, Research Center for Evolving Earth and Planets, 4259 B-14, Nagatsuta-cho, Midoritku, Yokohama, 226-8501, Japan Received 7 May 2005; revised 3 August 2005; accepted 24 August 2005. * For correspondence (fax þ 81 45 924 5823; e-mail [email protected]). Present address: Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan. Summary Jasmonic acid (JA) and methyl jasmonate (MeJA), collectively termed jasmonates, are ubiquitous plant signalling compounds. Several types of stress conditions, such as wounding and pathogen infection, cause endogenous JA accumulation and the expression of jasmonate-responsive genes. Although jasmonates are important signalling components for the stress response in plants, the mechanism by which jasmonate signalling contributes to stress tolerance has not been clearly de±ned. A comprehensive analysis of jasmonate- regulated metabolic pathways in Arabidopsis was performed using cDNA macroarrays containing 13516 expressed sequence tags (ESTs) covering 8384 loci. The results showed that jasmonates activate the coordinated gene expression of factors involved in nine metabolic pathways belonging to two functionally related groups: (i) ascorbate and glutathione metabolic pathways, which are important in defence responses to oxidative stress, and (ii) biosynthesis of indole glucosinolate, which is a defence compound occurring in the Brassicaceae family. We con±rmed that JA induces the accumulation of ascorbate, glutathione and cysteine and increases the activity of dehydroascorbate reductase, an enzyme in the ascorbate recycling pathway. These antioxidant metabolic pathways are known to be activated under oxidative stress conditions. Ozone (O 3 ) exposure, a representative oxidative stress, is known to cause activation of antioxidant metabolism. We showed that O 3 exposure caused the induction of several genes involved in antioxidant metabolism in the wild type. However, in jasmonate-de±cient Arabidopsis 12-oxophytodienoate reductase 3
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This note was uploaded on 08/01/2009 for the course HORT hor-11-12 taught by Professor Park during the Spring '09 term at A.T. Still University.

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Coordinated - The Plant Journal(2005 44 653668 doi 10.1111/j.1365-313X.2005.02560.x Coordinated activation of metabolic pathways for antioxidants

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