Abstract Detail



Comparative Genomics/Transcriptomics

Schneider, Adam [1], Braukmann, Thomas [2], Banerjee, Arjan [3], Stefanović, Saša [4].

Plastome sequencing of the last two lineages of parasitic plants: Lennoaceae and Krameriaceae.

Parasitic plants represent a remarkable example of convergent evolution across angiosperms, with 13 independent origins of direct (non-mycoheterotrophic) parasitism. Over the last several years, substantial effort among many research groups has gone into sequencing the plastomes from each of these groups in an effort to determine how predictable and repeatable are the dramatic changes in selection and gene loss found in the chloroplast genome. Intense study of particular species-rich and functionally diverse lineages such as the Orobanchaceae have contributed to sophisticated models of molecular evolution and plastome reduction. However, it is also important to look for shared characteristics of all independently evolved lineages. To that end we report our progress toward sequencing and annotating representatives of the two remaining families for whch the plastome is unknown: Lennoaceae and Krameriaceae, both of which are relatively species-poor and endemic to the Americas.
Sequencing two plastomes from the holoparasitic Lennoa madreporoides and Pholisma arenarium reveals that most plastid genes involved in photosynthesis function were lost but housekeeping genes retained in stem Lennoaceae. One major exception is the retention of the gene rbcL under putative purifying selection in P. arenarium, but the absence of this gene in L. madreporiodes. By contrast, The hemiparasite Kramera appears to have little to no plastome reduction in length or gene content compared to its non-parasitic relatives. Overall, this study supports convergent plastome evolution following the shift to heterotrophy in flowering plants.


Related Links:
Schneider et al. 2019. Convergent Plastome Evolution and Gene Loss in Holoparasitic Lennoaceae.


1 - Hendrix College, Biology, 1600 Washington Ave, Conway, AR, 72032, United States
2 - University Of Guelph, Centre For Biodiversity, 50 Stone Rd E, Guelph, ON, N1G 2W1, Canada
3 - University of Toronto Mississauga, Biology, Mississauga, ON, Canada
4 - University Of Toronto Mississauga, Department Of Biology, 3359 Mississauga Rd, Mississauga, ON, L5L 1C6, Canada

Keywords:
Lennoaceae
plastome
Krameriaceae
parasitic plant
parasitic reduction syndrmoe
Boraginales.

Presentation Type: Oral Paper
Number: 0004
Abstract ID:629
Candidate for Awards:None


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