Fanciullino Anne-Laure, Dhuique-Mayer Claudie, Luro François, Morillon Raphaël, Ollitrault Patrick
Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), UPR Amélioration Génétique des Espèces à Multiplication Végétative, Avenue Agropolis - TA A-75 / 02, 34398 Montpellier cedex 5, France.
J Agric Food Chem. 2007 Sep 5;55(18):7405-17. doi: 10.1021/jf070711h. Epub 2007 Aug 11.
The first objective of this paper was to analyze the potential role of allelic variability of carotenoid biosynthetic genes in the interspecific diversity in carotenoid composition of Citrus juices. The second objective was to determine the number of copies for each of these genes. Seven carotenoid biosynthetic genes were analyzed using restriction fragment length polymorphism (RFLP) and simple sequence repeats (SSR) markers. RFLP analyses were performed with the genomic DNA obtained from 25 Citrus genotypes using several restriction enzymes. cDNA fragments of Psy, Pds, Zds, Lcy-b, Lcy-e, Hy-b, and Zep genes labeled with [alpha-(32)P]dCTP were used as probes. For SSR analyses, two primer pairs amplifying two SSR sequences identified from expressed sequence tags (ESTs) of Lcy-b and Hy-b genes were designed. The number of copies of the seven genes ranged from one for Lcy-b to three for Zds. The genetic diversity revealed by RFLP and SSR profiles was in agreement with the genetic diversity obtained from neutral molecular markers. Genetic interpretation of RFLP and SSR profiles of four genes (Psy1, Pds1, Lcy-b, and Lcy-e1) enabled us to make inferences on the phylogenetic origin of alleles for the major commercial citrus species. Moreover, the results of our analyses suggest that the allelic diversity observed at the locus of both of lycopene cyclase genes, Lcy-b and Lcy-e1, is associated with interspecific diversity in carotenoid accumulation in Citrus. The interspecific differences in carotenoid contents previously reported to be associated with other key steps catalyzed by PSY, HY-b, and ZEP were not linked to specific alleles at the corresponding loci.
本文的首要目标是分析类胡萝卜素生物合成基因的等位基因变异在柑橘汁类胡萝卜素组成的种间多样性中的潜在作用。第二个目标是确定这些基因各自的拷贝数。使用限制性片段长度多态性（RFLP）和简单序列重复（SSR）标记分析了7个类胡萝卜素生物合成基因。使用几种限制性内切酶对从25个柑橘基因型获得的基因组DNA进行RFLP分析。用[α-(32)P]dCTP标记的Psy、Pds、Zds、Lcy-b、Lcy-e、Hy-b和Zep基因的cDNA片段用作探针。对于SSR分析，设计了两对引物，用于扩增从Lcy-b和Hy-b基因的表达序列标签（EST）中鉴定出的两个SSR序列。这7个基因的拷贝数范围从Lcy-b的1个到Zds的3个。RFLP和SSR图谱揭示的遗传多样性与从中性分子标记获得的遗传多样性一致。对四个基因（Psy1、Pds1、Lcy-b和Lcy-e1）的RFLP和SSR图谱进行遗传解读，使我们能够推断主要商业柑橘品种等位基因的系统发育起源。此外，我们的分析结果表明，在番茄红素环化酶基因Lcy-b和Lcy-e1位点观察到的等位基因多样性与柑橘类胡萝卜素积累的种间多样性相关。先前报道的与PSY、HY-b和ZEP催化的其他关键步骤相关的类胡萝卜素含量种间差异，与相应位点的特定等位基因无关。
