A mitochondrial ADXR-ADX-P450 electron transport chain is essential for maternal gametophytic control of embryogenesis in Arabidopsis

0557178 - ÚEB 2023 RIV US eng J - Journal Article
Bellido, A. M. - Distéfano, A. M. - Setzes, N. - Cascallares, M. M. - Oklešťková, Jana - Novák, Ondřej - Ramirez, J. A. - Zabaleta, E. J. - Fiol, D.F. - Pagnussat, G. C.
A mitochondrial ADXR-ADX-P450 electron transport chain is essential for maternal gametophytic control of embryogenesis in Arabidopsis.
Proceedings of the National Academy of Sciences of the United States of America. Roč. 119, č. 4 (2022), č. článku e2000482119. ISSN 0027-8424. E-ISSN 1091-6490
R&D Projects: GA MŠMT(CZ) EF16_019/0000827
Institutional support: RVO:61389030
Keywords : Embryogenesis * Gametophyte * Homocastasterone * p450 * Plant reproduction
OECD category: Biochemistry and molecular biology
Impact factor: 11.1, year: 2022
Method of publishing: Open access
http://doi.org/10.1073/pnas.2000482119

Mitochondrial adrenodoxins (ADXs) are small iron-sulfur proteins with electron transfer properties. In animals, ADXs transfer electrons between an adrenodoxin reductase (ADXR) and mitochondrial P450s, which is crucial for steroidogenesis. Here we show that a plant mitochondrial steroidogenic pathway, dependent on an ADXR-ADX-P450 shuttle, is essential for female gametogenesis and early embryogenesis through a maternal effect. The steroid profile of maternal and gametophytic tissues of wild-type (WT) and adxr ovules revealed that homocastasterone is the main steroid present inWT gametophytes and that its levels are reduced in the mutant ovules. The application of exogenous homocastasterone partially rescued adxr and P450 mutant phenotypes, indicating that gametophytic homocastasterone biosynthesis is affected in the mutants and that a deficiency of this hormone causes the phenotypic alterations observed. These findings also suggest not only a remarkable similarity between steroid biosynthetic pathways in plants and animals but also a common function during sexual reproduction.
Permanent Link: http://hdl.handle.net/11104/0331246