Abstract Detail

Genetics Section

Hernndez, David I. [1], Straub, Shannon [2], Liston, Aaron [3], Trujillo, Joshua [4], Edwards , Christopher  [2], Bailey, C. Donovan [5].

Plastome Organization and Sequence for the  Mimosoid Legume Leucaena trichandra.

The Mimosoideae genus Leucaena played an important historical role as a human food source in south-central Mexico, and it is a current element of multipurpose agriculture in many impoverished tropical regions of the world. Leucaena represents an interesting model system to investigate the impact of human translocation on the evolutionary trajectory of plant lineages. In association with ongoing work on the evolutionary history of Leucaena, we have sequenced the plastome of L. trichandra, one of the first plastome sequences from the Mimosoideae and a species involved in the origin of four of the five tetraploid species of Leucaena. De novo assembly of a 300bp insert paired-end Illumina HiSeq library generated the 164,692bp genome with ca. 2,000X coverage across single copy regions. The plastome contains 112 unique genes arranged in the typical large single copy, inverted repeat, small single copy regions. Other available legume plastomes are all members of the Papiloinoideae, a group known to harbor various plastome rearrangements. However, based on this single member of the diverse Mimosoideae, we have not observed large- or small-scale genomic rearrangements relative to closely related angiosperms. However, the L. trichandra plastome is similar to other legume plastomes in lacking an identifiable rpl22 gene and retaining an rps19 pseudogene. Preliminary analysis of tandem repeats identified approximately 200 repeats, some ranging to over 100 bp in length. The plastome will be used to investigate the potential importance of these repeat regions as well as rates of mutation across the genome relative to other legume plastomes. The L. trichandra plastome provides greater understanding of legume plastome diversification and, along with forthcoming plastome of other species of Leucaena, should help to identify precise maternal lines for several tetraploid species. Furthermore, the plastome may also be useful for plant breeders interested in using transgenic plastomes to improve on cultivated strains through a genome that offers the advantage of transgene containment to seed lines.

1 - New Mexico State University, Biology, PO Box 30001, MSC 3AF, Foster Hall 275, Las Cruces, NM, 88003, USA
2 - Oregon State University, Department Of Plant Biology, 2082 Cordley Hall, Corvallis, OR, 97331, USA
3 - Oregon State University, Department Of Botany & Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331-2902, USA, 541/737-5301
4 - New Mexico State University, Biology, PO Box 30001, MSC 3AF, Foster Hall 275, Las Cruces, NM, 88003, United States
5 - New Mexico State University, PO Box 30001 MSC 3AF, Las Cruces, NM, 88003, USA

Keywords:
mimosoid
plastome
chloroplast
plastid genome
Leucaena
legume.

Presentation Type: Oral Paper:Papers for Sections
Session: 22
Location: Rapids/Grove
Date: Tuesday, July 29th, 2014
Time: 9:30 AM
Number: 22003
Abstract ID:755
Candidate for Awards:Margaret Menzel Award