Lawley, W., Calvert, C., & Graham, I.A. (2013). Artemisia, Malaria, and the Red Queen. Science 342, 195-196
A review of Dana Dalrymple’s book “Artemisia annua, Artemisinin, ACTs & Malaria Control in Africa. Tradition, Science and Public Policy”
Larson, T.R., Branigan, C.A., Harvey, D., Penfield, T., Bowles, D.J. & Graham, I.A. (2013). A survey of artemisinic and dihydroartemisinic acid contents in glasshouse and global field grown populations of the artemisinin-producing Artemisia annua L. Industrial Crops & Products 45, 1-6.
The chemical synthetic steps to artemisinin have been the subject of research elsewhere with a suggestion that artemisinic and dihydroartemisinic acid could be taken from any source – microbial or plant – and efficiently and cheaply converted to artemisinin using a continuous-flow photoreactor design. One requirement and assumption for this technology to work with plant extracts is that there are A. annua varieties with very high precursor contents available as inputs. This paper reports that currently grown A. annua lines are poor sources of these precursors.
Townsend, T., Segura, V., Chigeza, G., Penfield, T., Rae, A.M., Harvey, D., Bowles, D.J. & Graham, I.A. (2013). The use of combining ability analysis to identify elite parents for Artemisia annua F1 hybrid production. PLoS ONE 8(4): e61989. doi:10.1371/journal.pone.0061989
This study demonstrates that combining ability, as determined by a diallel cross, can be used to identify elite parents for the production of improved A. annua hybrids. Furthermore, the selection of material for breeding using this approach was found to be consistent with our QTL-based molecular breeding approach of the earlier Science publication.
Graham, I.A., Besser, K., Blumer, S., Branigan, C.A., Czechowski, T., Elias, L., Guterman, I., Harvey, D., Isaac, P.G., Khan, A.M., Larson, T.R., Li, Y., Pawson, T., Penfield, T., Rae, A.M., Rathbone, D.A., Reid, S., Ross, J., Smallwood, M.F., Segura, V., Townsend, T., Vyas, D., Winzer, T. & Bowles, D.J. (2010). The genetic map of Artemisia annua L. identifies loci affecting yield of the antimalarial drug artemisinin. Science 327, 328-331.
This paper describes how deep sequencing of the A. annua transciptome was used to rapidly identify genes and molecular markers for fast-track breeding. Extensive genetic variation enabled us to build a detailed genetic map with nine linkage groups. Replicated field trials resulted in a quantitative trait loci (QTL) map which represented a major advance in the understanding of Artemisia genetics: the map can account for 41-62% of the variation in key traits controlling artemisinin yield and 30-38% variation in artemisinin concentration. The maps contributed greatly to the research programme allowing the rapid identification of parental lines with useful traits which could be used in the plant breeding programme. Enrichment for positive QTLs in parents of new high-yielding hybrids confirmed our plant breeding strategies were successful, and that we had the knowledge and tools to produce a robust A. annua crop.
A Science Perspectives article comments on the CNAP project "The botanical solution for malaria," W.K. Milhous and O.J. Weina, Science 327. no. 5963, pp. 279 - 280 (2010). http://www.sciencemag.org/cgi/content/full/327/5963/279?ijkey=zQHAfbLk/NWN2&keytype=ref&siteid=sci
This article was written by leading malaria research scientists, published in the same issue of Science as the genetic map paper. The authors suggest that the work undertaken by the project was ‘innovative in terms of the scale of the research and sophistication of the technologies involved’.