Narumi Mori1, Takahito Nomura2, Kohki Akiyama3. 1. Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka, 599-8531, Japan. 2. Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, 321-8505, Japan. 3. Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka, 599-8531, Japan. akiyama@biochem.osakafu-u.ac.jp.
Abstract
MAIN CONCLUSION: A cytochrome P450 and a 2-oxoglutarate-dependent dioxygenase genes responsible, respectively, for the biosyntheses of canonical and non-canonical strigolactones in Lotus japonicus were identified by transcriptome profiling and mutant screening. Strigolactones (SLs) are a group of apocarotenoids with diverse structures that act as phytohormones and rhizosphere signals. The model legume Lotus japonicus produces both canonical and non-canonical SLs, 5-deoxystrigol (5DS) and lotuslactone (LL), respectively, through oxidation of a common intermediate carlactone by the cytochrome P450 (CYP) enzyme MAX1. However, the pathways downstream of MAX1 and the branching point in the biosyntheses of 5DS and LL have not been elucidated. Here, we identified a CYP and a 2-oxoglutarate-dependent dioxygenase (2OGD) genes responsible, respectively, for the formation of Lotus SLs by transcriptome profiling using RNA-seq and screening of SL-deficient mutants from the Lotus retrotransposon 1 (LORE1) insertion mutant resource. The CYP and 2OGD genes were named DSD and LLD, respectively, after 5DS or LL defective phenotype of the mutants. The involvements of the genes in Lotus SL biosyntheses were confirmed by restoration of the mutant phenotype using Agrobacterium rhizogenes-mediated transformation to generate transgenic roots expressing the coding sequence. The transcript levels of DSD and LLD in roots as well as the levels of 5DS and LL in root exudates were reduced by phosphate fertilization and gibberellin treatment. This study can provide the opportunity to investigate how and why plants produce the two classes of SLs.
MAIN CONCLUSION: A cytochrome P450 and a 2-oxoglutarate-dependent dioxygenase genes responsible, respectively, for the biosyntheses of canonical and non-canonical strigolactones in Lotus japonicus were identified by transcriptome profiling and mutant screening. Strigolactones (SLs) are a group of apocarotenoids with diverse structures that act as phytohormones and rhizosphere signals. The model legume Lotus japonicus produces both canonical and non-canonical SLs, 5-deoxystrigol (5DS) and lotuslactone (LL), respectively, through oxidation of a common intermediate carlactone by the cytochrome P450 (CYP) enzyme MAX1. However, the pathways downstream of MAX1 and the branching point in the biosyntheses of 5DS and LL have not been elucidated. Here, we identified a CYP and a 2-oxoglutarate-dependent dioxygenase (2OGD) genes responsible, respectively, for the formation of Lotus SLs by transcriptome profiling using RNA-seq and screening of SL-deficient mutants from the Lotus retrotransposon 1 (LORE1) insertion mutant resource. The CYP and 2OGD genes were named DSD and LLD, respectively, after 5DS or LL defective phenotype of the mutants. The involvements of the genes in Lotus SL biosyntheses were confirmed by restoration of the mutant phenotype using Agrobacterium rhizogenes-mediated transformation to generate transgenic roots expressing the coding sequence. The transcript levels of DSD and LLD in roots as well as the levels of 5DS and LL in root exudates were reduced by phosphate fertilization and gibberellin treatment. This study can provide the opportunity to investigate how and why plants produce the two classes of SLs.
Authors: Adrian Alder; Muhammad Jamil; Mattia Marzorati; Mark Bruno; Martina Vermathen; Peter Bigler; Sandro Ghisla; Harro Bouwmeester; Peter Beyer; Salim Al-Babili Journal: Science Date: 2012-03-16 Impact factor: 47.728
Authors: Philip B Brewer; Kaori Yoneyama; Fiona Filardo; Emma Meyers; Adrian Scaffidi; Tancred Frickey; Kohki Akiyama; Yoshiya Seto; Elizabeth A Dun; Julia E Cremer; Stephanie C Kerr; Mark T Waters; Gavin R Flematti; Michael G Mason; Georg Weiller; Shinjiro Yamaguchi; Takahito Nomura; Steven M Smith; Koichi Yoneyama; Christine A Beveridge Journal: Proc Natl Acad Sci U S A Date: 2016-05-18 Impact factor: 11.205