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  • The seed transcriptome of Rafflesia reveals horizontal gene transfer and convergent evolution: Implications for conserving the world's largest flower
Title: The seed transcriptome of Rafflesia reveals horizontal gene transfer and convergent evolution: Implications for conserving the world's largest flower
Societal Impact Statement Summary

Rafflesiais of great interest as one of the only two plants known to have completely lost its chloroplast genome.Rafflesiais a holoparasite and an endophyte that lives inside the tissues of its host, a tropical grape vine (Tetrastigma), emerging only to bloom—with the largest flower of any plant. Here, we report the firstRafflesiaseed transcriptome and compare it with those of other plants to deepen our understanding of its extraordinary life history.

We assembled a transcriptome from RNA extracted from seeds of the Philippine endemicRafflesia speciosaand compared this with those of other plants, includingArabidopsis, parasitic plantsStrigaandCuscuta, and the mycoheterotrophic orchidAnoectochilus.

Genetic and metabolic seed pathways inRafflesiawere generally similar to the other plant species. However, there were some notable exceptions. We found evidence of horizontal transfer of a gene potentially involved in circumventing host defenses. Moreover, we identified a possible convergence among parasitic plants becauseRafflesia,Striga, andCuscutashared important similarities. We were unable to find evidence of genes involved in mycorrhizal symbiosis, suggesting that mycoheterotrophy is unlikely to play a role inRafflesiaparasitism.

To date, ex situ propagation ofRafflesiaby seed has been mostly unsuccessful. Our research is a bold step forward in understanding the fundamentals ofRafflesiaseed biology that will inform the continued propagation and seed‐banking efforts concerning this recalcitrant plant. We discuss our findings in the broader context of the conservation of a genus in peril.

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Award ID(s):
2204938
NSF-PAR ID:
10406693
Author(s) / Creator(s):
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Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
PLANTS, PEOPLE, PLANET
ISSN:
2572-2611
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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