title: A Tandem Array of ent-Kaurene Synthases in Maize with Roles in Gibberellin and More Specialized Metabolism.
abstract: While most commonly associated with its role in gibberellin phytohormone biosynthesis, ent-kaurene also serves as an intermediate in more specialized diterpenoid metabolism, as exemplified by the more than 800 known derived natural products. Among these are the maize kauralexins. However, no ent-kaurene synthases (KSs) have been identified from maize. The maize gibberellin-deficient dwarf-5 (d5) mutant has been associated with a loss of KS activity. The relevant genetic lesion has been previously mapped, and was found here to correlate with the location of the KS-like gene ZmKSL3. Intriguingly, this forms part of a tandem array with two other terpene synthases (TPSs). Although one of these, ZmTPS1, has been previously reported to encode a sesquiterpene synthase, and both ZmTPS1 and that encoded by the third gene, ZmKSL5, have lost the N-terminal γ-domain prototypically associated with KS(L)s, all three genes fall within the KS(L) or TPS-e subfamily. Here it is reported that all three genes encode enzymes that are targeted to the plastid in planta, where diterpenoid biosynthesis is initiated, and which all readily catalyze the production of ent-kaurene. Consistent with the closer phylogenetic relationship of ZmKSL3 with previously identified KSs from cereals, only transcription of this gene is affected in d5 plants. On the other hand, the expression of all three of these genes is inducible, suggesting a role in more specialized metabolism, such as that of the kauralexins. Thus, these results clarify not only gibberellin phytohormone, but also diterpenoid phytoalexin biosynthesis in this important cereal crop plant.
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Jingye
authors.initials: J
authors.lastname: Fu
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Fei
authors.identifier: http://orcid.org/0000-0003-4700-1409
authors.initials: F
authors.lastname: Ren
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Xuan
authors.initials: X
authors.lastname: Lu
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Hongjie
authors.identifier: http://orcid.org/0000-0003-2014-5429
authors.initials: H
authors.lastname: Mao
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Meimei
authors.initials: M
authors.lastname: Xu
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.).
authors.forename: Jörg
authors.identifier: http://orcid.org/0000-0003-0510-1006
authors.initials: J
authors.lastname: Degenhardt
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.) rjpeters@iastate.edu qwang@sicau.edu.cn.
authors.forename: Reuben J
authors.identifier: http://orcid.org/0000-0003-4691-8477
authors.initials: RJ
authors.lastname: Peters
authors.affiliation: Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China 611130 (J.F., F.R., H.M., Q.W.);Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (X.L., M.X., R.J.P.); andInstitute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, D-06120 Halle/Saale, Germany (J.D.) rjpeters@iastate.edu qwang@sicau.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000378:metabolism; D005875:Gibberellins / Q000378:metabolism*; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D012717:Sesquiterpenes / Q000378:metabolism; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics; D000094162:Phytoalexins
chemical_list: D045786:Diterpenes, Kaurane; D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012717:Sesquiterpenes; D019883:Alkyl and Aryl Transferases; C105712:ent-kaurene synthetase B; C108877:terpene synthase; D000094162:Phytoalexins