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Genomes of leafy and leafless Platanthera orchids illuminate the evolution of mycoheterotrophy.

Authors :
Li MH
Liu KW
Li Z
Lu HC
Ye QL
Zhang D
Wang JY
Li YF
Zhong ZM
Liu X
Yu X
Liu DK
Tu XD
Liu B
Hao Y
Liao XY
Jiang YT
Sun WH
Chen J
Chen YQ
Ai Y
Zhai JW
Wu SS
Zhou Z
Hsiao YY
Wu WL
Chen YY
Lin YF
Hsu JL
Li CY
Wang ZW
Zhao X
Zhong WY
Ma XK
Ma L
Huang J
Chen GZ
Huang MZ
Huang L
Peng DH
Luo YB
Zou SQ
Chen SP
Lan S
Tsai WC
Van de Peer Y
Liu ZJ
Source :
Nature plants [Nat Plants] 2022 Apr; Vol. 8 (4), pp. 373-388. Date of Electronic Publication: 2022 Apr 21.
Publication Year :
2022

Abstract

To improve our understanding of the origin and evolution of mycoheterotrophic plants, we here present the chromosome-scale genome assemblies of two sibling orchid species: partially mycoheterotrophic Platanthera zijinensis and holomycoheterotrophic Platanthera guangdongensis. Comparative analysis shows that mycoheterotrophy is associated with increased substitution rates and gene loss, and the deletion of most photoreceptor genes and auxin transporter genes might be linked to the unique phenotypes of fully mycoheterotrophic orchids. Conversely, trehalase genes that catalyse the conversion of trehalose into glucose have expanded in most sequenced orchids, in line with the fact that the germination of orchid non-endosperm seeds needs carbohydrates from fungi during the protocorm stage. We further show that the mature plant of P. guangdongensis, different from photosynthetic orchids, keeps expressing trehalase genes to hijack trehalose from fungi. Therefore, we propose that mycoheterotrophy in mature orchids is a continuation of the protocorm stage by sustaining the expression of trehalase genes. Our results shed light on the molecular mechanism underlying initial, partial and full mycoheterotrophy.<br /> (© 2022. The Author(s).)

Details

Language :
English
ISSN :
2055-0278
Volume :
8
Issue :
4
Database :
MEDLINE
Journal :
Nature plants
Publication Type :
Academic Journal
Accession number :
35449401
Full Text :
https://doi.org/10.1038/s41477-022-01127-9