Abstract
Strigolactones (SLs) are rhizosphere signalling molecules and phytohormones. The biosynthetic pathway of SLs in tomato has been partially elucidated, but the structural diversity in tomato SLs predicts that additional biosynthetic steps are required. Here, root RNA-seq data and co-expression analysis were used for SL biosynthetic gene discovery. This strategy resulted in a candidate gene list containing several cytochrome P450s. Heterologous expression in Nicotiana benthamiana and yeast showed that one of these, CYP712G1, can catalyse the double oxidation of orobanchol, resulting in the formation of three didehydro-orobanchol (DDH) isomers. Virus-induced gene silencing and heterologous expression in yeast showed that one of these DDH isomers is converted to solanacol, one of the most abundant SLs in tomato root exudate. Protein modelling and substrate docking analysis suggest that hydroxy-orbanchol is the likely intermediate in the conversion from orobanchol to the DDH isomers. Phylogenetic analysis demonstrated the occurrence of CYP712G1 homologues in the Eudicots only, which fits with the reports on DDH isomers in that clade. Protein modelling and orobanchol docking of the putative tobacco CYP712G1 homologue suggest that it can convert orobanchol to similar DDH isomers as tomato.
| Original language | English |
|---|---|
| Pages (from-to) | 1884-1899 |
| Number of pages | 16 |
| Journal | New Phytologist |
| Volume | 235 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Sept 2022 |
Bibliographical note
Funding Information:This work was supported by a China Scholarship Council (CSC) scholarship 201506300065 (to YW), ERC Advanced grant CHEMCOMRHIZO 670211 (to HJB, KF and LD) and Marie Curie fellowship NEMHATCH 793795 (to LD). SM is funded by the Scottish Government Rural and Environment Science and Analytical Services Division (RESAS). pKG1662 vector was kindly provided by Professor Michel A. Haring (Plant Physiology, University of Amsterdam). We thank Koichi Yoneyama and Xionan Xie (Utsonomiya University) for kindly providing the tentatively identified 7‐hydroxy‐orobanchol, Alain de Mesmaeker (Syngenta, Stein Switzerland) for providing GR24, Professor Binne Zwanenburg (Radboud University Nijmegen, the Netherlands) for providing four orobanchol stereoisomers and Professor Koichi Yoneyama (Center for Bioscience Research and Education, Utsunomiya University, Japan) for providing solanacol standard. We acknowledge Professor David Nelson (UC Riverside, USA) for help with CYP712 gene classification.
Funding Information:
This work was supported by a China Scholarship Council (CSC) scholarship 201506300065 (to YW), ERC Advanced grant CHEMCOMRHIZO 670211 (to HJB, KF and LD) and Marie Curie fellowship NEMHATCH 793795 (to LD). SM is funded by the Scottish Government Rural and Environment Science and Analytical Services Division (RESAS). pKG1662 vector was kindly provided by Professor Michel A. Haring (Plant Physiology, University of Amsterdam). We thank Koichi Yoneyama and Xionan Xie (Utsonomiya University) for kindly providing the tentatively identified 7-hydroxy-orobanchol, Alain de Mesmaeker (Syngenta, Stein Switzerland) for providing GR24, Professor Binne Zwanenburg (Radboud University Nijmegen, the Netherlands) for providing four orobanchol stereoisomers and Professor Koichi Yoneyama (Center for Bioscience Research and Education, Utsunomiya University, Japan) for providing solanacol standard. We acknowledge Professor David Nelson (UC Riverside, USA) for help with CYP712 gene classification.
Publisher Copyright:
© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.
Funding
This work was supported by a China Scholarship Council (CSC) scholarship 201506300065 (to YW), ERC Advanced grant CHEMCOMRHIZO 670211 (to HJB, KF and LD) and Marie Curie fellowship NEMHATCH 793795 (to LD). SM is funded by the Scottish Government Rural and Environment Science and Analytical Services Division (RESAS). pKG1662 vector was kindly provided by Professor Michel A. Haring (Plant Physiology, University of Amsterdam). We thank Koichi Yoneyama and Xionan Xie (Utsonomiya University) for kindly providing the tentatively identified 7‐hydroxy‐orobanchol, Alain de Mesmaeker (Syngenta, Stein Switzerland) for providing GR24, Professor Binne Zwanenburg (Radboud University Nijmegen, the Netherlands) for providing four orobanchol stereoisomers and Professor Koichi Yoneyama (Center for Bioscience Research and Education, Utsunomiya University, Japan) for providing solanacol standard. We acknowledge Professor David Nelson (UC Riverside, USA) for help with CYP712 gene classification. This work was supported by a China Scholarship Council (CSC) scholarship 201506300065 (to YW), ERC Advanced grant CHEMCOMRHIZO 670211 (to HJB, KF and LD) and Marie Curie fellowship NEMHATCH 793795 (to LD). SM is funded by the Scottish Government Rural and Environment Science and Analytical Services Division (RESAS). pKG1662 vector was kindly provided by Professor Michel A. Haring (Plant Physiology, University of Amsterdam). We thank Koichi Yoneyama and Xionan Xie (Utsonomiya University) for kindly providing the tentatively identified 7-hydroxy-orobanchol, Alain de Mesmaeker (Syngenta, Stein Switzerland) for providing GR24, Professor Binne Zwanenburg (Radboud University Nijmegen, the Netherlands) for providing four orobanchol stereoisomers and Professor Koichi Yoneyama (Center for Bioscience Research and Education, Utsunomiya University, Japan) for providing solanacol standard. We acknowledge Professor David Nelson (UC Riverside, USA) for help with CYP712 gene classification.
Keywords
- CYP712G1
- orobanchol
- oxidation
- solanacol
- strigolactone biosynthesis
- tomato (Solanum lycopersicum)