No.42 - è¾²æ¥çç©è³æºç ç©¶æ

More documents

Recommendations

Info

REGULATION OF PLANT HORMONE BIOSYNTHESES 7 Fig. 4. Abscisic acid catabolism. 8’-Hydroxylation is catalyzed by CYP707A1-A4 in Arabidopsis. and Eiji NAMBARA have worked intensively about the cloning and characterization of the ABA catabolic enzyme. P450s are large family of enzymes that catalyze the oxidation of various low molecular weight compounds. They have been conserved for billions of years and exist in most of the organisms on the earth ranging from bacteria to mammals. In mammals, P450s play a major role in drug metabolism, and have been a center of research in the pharmaceutical field. In plants, P450s participate in numerous aspects of plant metabolism, which include phytohormones and secondary metabolites (SCHULER 1996; CHAPPLE 1998). Completion of the Arabidopsis genome sequencing has revealed that there are at least 272 P450 genes in this single organism. In the following completion of the rice genome sequencing, nearly 450 P450 genes have been identified (http://drnelson.utmem.edu/rice.html). These numbers obviously indicate how widely these genes have evolved and deeply rooted in the plant life cycle. The genome sequencing efforts were successful in accumulating sequence information, however, it is still a major challenge to identify the function of each gene. This will be a major task in the post genomic era, and will require novel approaches as well as systematic analysis of the gene. P450s are especially challenging since in most cases, the substrate of the enzyme cannot be easily predicted. Furthermore, the number of possible steps where P450 participates along the metabolic pathways is largely unknown. In order to identify the P450 gene for ABA 8’-hydroxylase, we have set out to search for the gene of our interest among hundreds of candidate genes. Once the gene for ABA 8’-hydroxylase is identified, it would be possible to fine-tune the level of ABA in plants, and thus, would expect to improve drought tolerance as well as to prevent precocious germination in crops. Therefore, the identification of this gene would have an enormous impact on the agricultural industry. Our extensive and careful prediction led to the first successful identification of the members of CYP707A family as ABA 8’-hydroxylase genes. Expression analysis and genetic analysis demonstrated that CYP707 genes play a regulatory role in vivo to define the ABA level during these processes (KUSHIRO et al. 2004).
8 Yuji KAMIYA References AKIYOSHI, D.E., KLEE, H., AMASINO, R.M., NESTER, E.W. and GORDON, M.P. (1984) T-DNA of Agrobacterium tumefaciens encodes an enzyme of cytokinin biosynthesis. Proc. Natl. Acad. Sci. USA 81: 5994-5998. ARAI, S., TODOROKI, Y., IBARAKI, S., NAOE, Y., HIRAI, N. and OHIGASHI, H. (1999) Synthesis and activity of 3’-chloro, -bromo, and -iodoabscisic acids, and biological activity of 3’-fluoro-8’-hydroxy abscisic acid. Phytochemistry 52: 1185-1193. ÅSTOT, C., DOLEZAL, K., NORDSTRÖM, A., WANG, Q., KUNKEL, T., MORITZ, T., CHUA, N.H. and SANDBERG, G. (2000) An alternative cytokinin biosynthesis pathway. Proc. Natl. Acad. Sci. USA 97: 14778-14783. BARRY, G.F., ROGERS, S.G., FRALEY, R.T. and BRAND, L. (1984) Identification of a cloned cytokinin biosynthetic gene. Proc. Natl. Acad. Sci. USA 81: 4776-4780. BASSIL, N.V., MOK, D. and MOK, M.C. (1993) Partial Purification of a cis-trans-Isomerase of Zeatin from Immature Seed of Phaseolus vulgaris L. Plant Physiol. 102: 867-872. BEWLEY, J.D. and BLACK, M. (1982) Physiology and biochemistry of seeds. (Volume 2). Viability, dormancy and environmental control. (Berlin, Germany: Springer-Verlag). BORTHWICK, H.A., HENDRICKS, S.B., PARKER, M.W., TOOLE, E.H. and TOOLE, V.K. (1952) A reversible photoreaction controlling seed germination. Proc. Natl. Acad. Sci. USA 38: 662-666. BUTLER, W.L., NORRIS, K.H., SIEGELMAN, H.W. and HENDRICKS, S.B. (1959) Detection, assay, and preliminary purification of the pigment controlling phtoresponsive development of plants. Proc. Natl. Acad. Sci. USA 45: 1703-1708. CHAPPLE, C. (1998) Molecular genetics analysis of plant cytochrome P450-dependent monooxygenases. Annu. Rev. Plant Physiol. Mol. Biol. 49: 311-343. CHEN, C.M. and HALL, R.H. (1969) Biosynthesis of N 6 -(d2-isopentenyl) adenosine in the transfer ribonucleic acid of cultured tabacco pith tissue. Phytochemistry 8: 1687-1696. CHEN, C.M. and LEISNER, S.M. (1984) Modification of cytokinins by cauliflower microsomal enzymes. Plant Physiol. 75: 442-446. CONE, J.W. and SPRUIT, C.J.P. (1983) Imbibition conditions and seed dormancy of Arabidopsis thaliana. Physiol. Plant. 59: 416-420. CUTLER, A.J. and KROCHKO, J.E. (1999) Formation and breakdown of ABA. Trends Plant Sci. 4: 472-478. DAVIES, P.J. (1995) Plant Hormones: Physiology, Biochemistry and Molecular Biology. (Dordrecht, The Netherlands: Kluwer Academic Publishers). DERKX, M.P.M., VERMEER, E. and KARSSEN, C.M. (1994) Gibberellins in seeds of Arabidopsis thaliana: Biological activities, identification and effects of light and chilling on endogenous levels. Plant Growth Regul. 15: 223-234. ESTEVEZ, J.M., CANTERO, A., ROMERO, C., KAWAIDE, H., JIMENEZ, L.F., KUZUYAMA, T., SETO, H., KAMIYA, Y. and LEON, P. (2000) Complementation of albino mutant cla1-1 of Arabidopsis thaliana by 1-deoxy-Dxylulose: A CLA1 gene require for the non-mevalonate pathway. Plant Physiol. 124: 95-104. GILLARD, D.F. and WALTON, D.C. (1976) Abscisic acid metabolism by a cell-free preparation from Echinocystis lobata liquid endosperm. Plant Physiol. 58: 790-795. HARRISON, M. A. and WALTON, D.C. (1975) Abscisic acid metabolism in water-stressed bean leaves. Plant Physiol. 56: 250-254. HEDDEN, P. and KAMIYA, Y. (1997) Gibberellin biosynthesis: Enzymes, genes and their regulation. Annu. Rev. Plant Phys. Plant Mol. Biol. 48: 431-460. HEMMERLIN, A., HOEFFLER, J. F., MEYER, O., TRITSCH, D., KAGAN, I.A., GROSDEMANGE-BILLIARD, C., ROHMER, M. and BACH, T.J. (2003) Cross-talk between the cytosolic mevalonate and the plastidial methylerythritol phosphate pathways in tobacco Bright Yellow-2 cells. J. Biol. Chem. 278: 26666-26676.
Page 1 and 2: ISSN 0435-1096 Gamma Field Symposia
Page 3 and 4: The lecturers and the members of th
Page 5 and 6: KANEKO, T. KARITA, E. KASHIMA, M. K
Page 7 and 8: TANO, S. TSUCHIDA, Y. TSUTSUMI, N.
Page 9 and 10: The Symposium Committee Shigeki NAG
Page 11 and 12: CONTENTS Y. KAMIYA Biosyntheses and
Page 13 and 14: 2 Yuji KAMIYA Fig. 1. Gibberellin b
Page 15 and 16: 4 Yuji KAMIYA using the receptor pr
Page 17: 6 Yuji KAMIYA Fig. 3. Origin of sid
Page 21 and 22: 10 Yuji KAMIYA SHINOMURA, T. (1997)
Page 23 and 24: 12 Yuji KAMIYA 8’ 8’ 273
Page 25 and 26: 14 Motoyuki ASHIKARI, Hironori ITOH
Page 37 and 38: 26 Atsuhiro OKA and how their signa
Page 39 and 40: 28 Atsuhiro OKA At almost the same
Page 41 and 42: 30 Atsuhiro OKA division for xylem
Page 43 and 44: 32 Atsuhiro OKA the RR domain in th
Page 45 and 46: 34 Atsuhiro OKA Fig. 4. Cross-talk
Page 47 and 48: 36 Atsuhiro OKA OKA, A., SAKAI, H.
Page 49 and 50: 38 Atsuhiro OKA ARR4 PHYB PHYBP
Page 51 and 52: Gamma Field Symposia, No. 42, 2003
Page 53 and 54: ETHYLENE-SIGNALING PATHWAY 43 signa
Page 55 and 56: ETHYLENE-SIGNALING PATHWAY 45 The f
Page 57 and 58: ETHYLENE-SIGNALING PATHWAY 47 Snf3p
Page 59 and 60: ETHYLENE-SIGNALING PATHWAY 49 In sp
Page 61 and 62: ETHYLENE-SIGNALING PATHWAY 51
Page 63 and 64: Gamma Field Symposia, No. 42, 2003
Page 65 and 66: MECHANISM OF BRASSINOSTEROID SIGNAL
Page 67 and 68: MECHANISM OF BRASSINOSTEROID SIGNAL
Page 69 and 70:
MECHANISM OF BRASSINOSTEROID SIGNAL
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
68 Yoshikatsu MATSUBAYASHI are grow
Page 79 and 80:
70 Yoshikatsu MATSUBAYASHI Fig. 3.
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
76 Yoshikatsu MATSUBAYASHI 33. Yang
Page 87 and 88:
78 Yoshikatsu MATSUBAYASHI GUS
Page 89 and 90:
80 BRI1
Page 91 and 92:
82 BRI 10
Page 93 and 94:
84 100
Page 95 and 96:
86 PSK 23 BIL1/CFP
Page 97:
87 2 2
show all

No.42 - è¾²æ¥­çç©è³æºç ç©¶æ

Create successful ePaper yourself

Delete template?

Save as template?

No.42 - è¾²æ¥çç©è³æºç ç©¶æ