Campus Units

Biochemistry, Biophysics and Molecular Biology

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-2016

Journal or Book Title

Plant Physiology

Volume

170

Issue

2

First Page

742

Last Page

751

DOI

10.1104/pp.15.01727

Abstract

While most commonly associated with its role in gibberellin (GA) 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 GA-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 sub-family. 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.

Comments

This is a manuscript of an article published as A Tandem Array of ent-Kaurene Synthases in Maize with Roles in Gibberellin and More Specialized Metabolism. Jingye Fu, Fei Ren, Xuan Lu, Hongjie Mao, Meimei Xu, Jörg Degenhardt, Reuben J. Peters, Qiang Wang. Plant Physiology Feb 2016, 170 (2) 742-751, DOI: 10.1104/pp.15.01727. Posted with permission.

Copyright Owner

American Society of Plant Biologists

Language

en

File Format

application/pdf