University Illinois, USA. USA.
Ray Ming
Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
RESUMEN (ABSTRACT)
Papaya is a major fruit crop in tropical and sub-tropical regions worldwide and is known for its nutritional benefits and medicinal applications. The draft genome sequence of ÔSunUpÕ papaya is the first commercial virus-resistant transgenic crop to be sequenced. The papaya genome is three times the size of the Arabidopsis genome, but contains fewer genes, including significantly fewer disease resistance gene analogs. Comparison of the five sequenced clade members of angiosperm suggests a minimal angiosperm gene set of 13,311. A lack of recent genome duplication, atypical of other angiosperm genomes sequenced to date, may account for the smaller papaya gene number in most functional groups. Against a background of generally fewer genes than Arabidopsis, some papaya gene functional groups have undergone striking single-gene amplifications in gene number within particular functional groups suggest roles in the evolution of tree-like habit, deposition and remobilization of starch reserves, attraction of seed dispersal agents, and adaptation to tropical daylengths. Transgenesis at three locations is closely associated with chloroplast insertions into the nuclear genome, and with Topo I recognition sites. Papaya offers numerous advantages as a system for fruit tree functional genomics, and this draft genome sequence provides the foundation for revealing the basis of CaricaÕs distinguishing morpho-physiological, medicinal, and nutritional properties.