The oxygenation reactions catalyzed by cytochromes P450 (CYPs) play critical roles in plant natural products biosynthesis. At the same time, CYPs are one of most challenging enzymes to functionally characterize due to the difficulty of recombinantly expressing these membrane-associated monooxygenases. In the course of investigating rice diterpenoid biosynthesis, we have developed a synthetic biology approach for functional expression of relevant CYPs in Escherichia coli. In certain cases, activity was observed for only one of two closely related paralogs although it seems clear that related reactions are required for production of the known diterpenoids. Here, we report that optimization of the recombinant expression system enabled characterization of not only these previously recalcitrant CYPs, but also discovery of additional activity relevant to rice diterpenoid biosynthesis. Of particular interest, CYP701A8 was found to catalyze 3β-hydroxylation of syn-pimaradiene, which is presumably relevant to momilactone biosynthesis, while CYP71Z6 & 7 were found to catalyze multiple reactions, with CYP71Z6 catalyzing the production of 2α,3α-dihydroxy-ent-isokaurene via 2α-hydroxy-ent-isokaurene, and CYP71Z7 catalyzing the production of 3α-hydroxy-ent-cassadien-2-one via 2α-hydroxy-ent-cassadiene and ent-cassadien-2-one, which may be relevant to oryzadione and phytocassane biosynthesis, respectively.
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http://dx.doi.org/10.1007/s00253-015-6496-2 | DOI Listing |
J Integr Plant Biol
January 2025
National Key Laboratory for Tropical Crop Breeding, School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya, 572025, China.
Casbene and neocembrene are casbene-type macrocyclic diterpenes; their derivatives play significant roles in plant defense and have pharmaceutical applications. We had previously characterized a casbene synthase, TERPENE SYNTHASE 28 (OsTPS28), in rice (Oryza sativa). However, the mechanism of neocembrene biosynthesis in rice remained unclear.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Anhui Province Key Laboratory of Bioactive Natural Products, School of Pharmacy, Anhui University of Chinese Medicine, Hefei 230000, China.
Thirteen new cyathane diterpene glycosides, hericinosides A-M (-), and six known analogs, were isolated from the rice media fermentation of the medicinal fungus . The sugar parts of and were highly modified, forming a unique 5/6/7/5/5/5 ring new skeleton system. All structures were elucidated based on spectroscopic data, and their relative configurations were determined according to the ROESY analysis.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
State Key Laboratory of Rice Biology and Breeding, Zhejiang Key Laboratory of Biology and Ecological Regulation of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
CRISPR-Cas9 genome editing systems have revolutionized plant gene functional studies by enabling the targeted introduction of insertion-deletions (INDELs) via the nonhomologous end-joining (NHEJ) pathway. Frameshift-inducing INDELs can introduce a premature termination codon and, in other instances, can lead to the appearance of new proteins. Here, we found that mutations in the rice jasmonate (JA) signaling gene by CRISPR-Cas9-based genome editing did not affect canonical JA signaling.
View Article and Find Full Text PDFGenomics
December 2024
College of Life Science, Shenyang Normal University, No. 253 Huanghe North Street, Shenyang, Liaoning 110034, China. Electronic address:
The gradual rise of CO is one of the global climate changes, Cd stress is also a major abiotic stress factor that affects rice (Oryza sativa L.). The rice seedlings were treated under two CO concentrations and two CdCl concentrations for 7 days (treatments names: 400 ± 20 μmol mol CO and 0 μmol L CdCl concentrations, AC; 400 ± 20 μmol mol CO and 150 μmol L CdCl concentrations, Cd; 800 ± 20 μmol mol CO and 0 μmol L CdCl concentrations, EC; 800 ± 20 μmol mol CO and 150 μmol L CdCl concentrations, EC + Cd).
View Article and Find Full Text PDFPlant Cell
December 2024
State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Well-conserved mitogen-activated protein kinase (MAPK) cascades are essential for orchestrating of a wide range of cellular processes in plants, including defense responses against pathogen attack. NAC transcription factors (TFs) play important roles in plant immunity, but their targets and how they are regulated remain largely unknown. Here, we identified the TF OsNAC29 as a key component of a MAPK signaling pathway involved in rice (Oryza sativa) disease resistance.
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