Belfanti Enrico, Silfverberg-Dilworth Eve, Tartarini Stefano, Patocchi Andrea, Barbieri Massimo, Zhu Jun, Vinatzer Boris A, Gianfranceschi Luca, Gessler Cesare, Sansavini Silviero
Department of Fruit Tree and Woody Plant Sciences, University of Bologna, 40127 Bologna, Italy.
Proc Natl Acad Sci U S A. 2004 Jan 20;101(3):886-90. doi: 10.1073/pnas.0304808101. Epub 2004 Jan 8.
The Vf gene from the wild species Malus floribunda 821 is the most studied apple scab resistance gene. Several molecular markers mapping around this gene were the starting point for a positional cloning project. The analysis of the bacterial artificial chromosome clones spanning the Vf region led to the identification of a cluster of genes homologous to the Cladosporium fulvum resistance gene family of tomato. One of these genes, HcrVf2 (homologue of the C. fulvum resistance genes of the Vf region), was used to transform the susceptible apple cultivar Gala. Four independent transformed lines resistant to apple scab were produced, proving that HcrVf2 is sufficient to confer scab resistance to a susceptible cultivar. The results show that direct gene transfer between cross-compatible species can be viable when, as in apple, the use of backcrosses to introduce resistance genes from wild species cannot exactly reconstitute the heterozygous genotype of clonally propagated cultivars.
来自野生种苹果花红821的Vf基因是研究最多的苹果黑星病抗性基因。围绕该基因定位的几个分子标记是一个图位克隆项目的起点。对跨越Vf区域的细菌人工染色体克隆进行分析，导致鉴定出一组与番茄叶霉病抗性基因家族同源的基因。其中一个基因HcrVf2（Vf区域叶霉病抗性基因的同源物）被用于转化感病苹果品种嘎啦。产生了四个对苹果黑星病具有抗性的独立转化株系，证明HcrVf2足以赋予感病品种黑星病抗性。结果表明，当像苹果一样，利用回交从野生种引入抗性基因不能精确重建无性繁殖品种的杂合基因型时，交叉亲和物种之间的直接基因转移是可行的。
