Functional Characterization of Genes Coding for Novel β-D-Glucosidases Involved in the Initial Step of Secoiridoid Glucosides Catabolism in Centaurium erythraea Rafn.
2022
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Authors:
Božunović, JelenaMilutinović, Milica
Aničić, Neda
Skorić, Marijana
Matekalo, Dragana
Živković, Suzana
Dragićević, Milan
Filipović, Biljana
Banjanac, Tijana
Petrović, Luka
Mišić, Danijela
Document Type:
Article (Published version)
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© 2022 Božunović, Milutinović, Aničić, Skorić, Matekalo, Živković, Dragićević, Filipović, Banjanac, Petrović and Mišić.
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Show full item recordAbstract:
Secoiridoid glucosides (SGs) are monoterpenoids derived from the iridoid cyclopentane-C-pyran skeleton with β-D glucose linked at C1 position. Coordinated metabolic processes, such as biosynthesis and catabolism of SGs, ensure constitutive presence of these bitter tasting compounds in plant tissues, which plays a decisive role in the defense against pathogens and herbivores. These compounds are susceptible to hydrolysis mediated by enzymes β-glucosidases, and the resulting aglycones are subsequently directed toward different metabolic pathways in plants. Function of two β-D-glucosidases (named CeBGlu1 and CeBGlu2) from centaury (Centaurium erythraea Rafn; fam. Gentianaceae), belonging to the glycoside hydrolase 1 (GH1) family, was confirmed using in vitro assays with recombinant proteins, following their heterologous expression in E. coli and His-tag affinity purification. Although they show slightly differential substrate preference, both isoforms display high specificity toward SGs and the organ-specific distribution of transcripts was positively correlated with the content of SGs in diploid and tetraploid C. erythraea plants. Transient overexpression of CeBGlu1 and CeBGlu2 in C. erythraea leaves induced changes in metabolite profiles. The effectiveness of transgene overexpression has been altered by plant ploidy. UHPLC/DAD/(±)HESI - MS2 profiling of leaves of diploid and tetraploid C. erythraea genotypes revealed that the amounts of major SGs; sweroside, swertiamarin, and gentiopicrin was decreased in agroinfiltrated leaves, especially when CeBGlu1 and CeBGlu2 were co-expressed with transgene silencing suppressor p19. The work demonstrates that in planta metabolic engineering adopting transient overexpression of CeBGlu1 and CeBGlu2 is a suitable tool for the modulation of SGs content and glucosides/aglycones ratio, which might have substantial effects on overall phytochemistry of C. erythraea.
Keywords:
Centaurium erythraea; Agroinfiltration; Beta glucosidase; Functional characterization; Secoiridoid glucosidesSource:
Frontiers in Plant Science, 2022, 13, 914138-Funding / projects:
- Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding - 200007 (University of Belgrade, Institute for Biological Research 'Siniša Stanković') (RS-MESTD-inst-2020-200007)
- Physiological, chemical and molecular analysis of the diversity of selected rare and endangered plant species and application of biotechnology for ex situ conservation and production of biologically active compounds (RS-MESTD-Basic Research (BR or ON)-173024)
DOI: 10.3389/fpls.2022.914138
ISSN: 1664-462X
PubMed: 35812935
WoS: 000821852200001
Scopus: 2-s2.0-85134024140
URI
https://www.frontiersin.org/articles/10.3389/fpls.2022.914138/fullhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC9260424
http://radar.ibiss.bg.ac.rs/handle/123456789/5073