Kahlau Sabine, Aspinall Sue, Gray John C, Bock Ralph
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, D-14476, Germany.
J Mol Evol. 2006 Aug;63(2):194-207. doi: 10.1007/s00239-005-0254-5. Epub 2006 Jul 7.
Tomato, Solanum lycopersicum (formerly Lycopersicon esculentum), has long been one of the classical model species of plant genetics. More recently, solanaceous species have become a model of evolutionary genomics, with several EST projects and a tomato genome project having been initiated. As a first contribution toward deciphering the genetic information of tomato, we present here the complete sequence of the tomato chloroplast genome (plastome). The size of this circular genome is 155,461 base pairs (bp), with an average AT content of 62.14%. It contains 114 genes and conserved open reading frames (ycfs). Comparison with the previously sequenced plastid DNAs of Nicotiana tabacum and Atropa belladonna reveals patterns of plastid genome evolution in the Solanaceae family and identifies varying degrees of conservation of individual plastid genes. In addition, we discovered several new sites of RNA editing by cytidine-to-uridine conversion. A detailed comparison of editing patterns in the three solanaceous species highlights the dynamics of RNA editing site evolution in chloroplasts. To assess the level of intraspecific plastome variation in tomato, the plastome of a second tomato cultivar was sequenced. Comparison of the two genotypes (IPA-6, bred in South America, and Ailsa Craig, bred in Europe) revealed no nucleotide differences, suggesting that the plastomes of modern tomato cultivars display very little, if any, sequence variation.
番茄，即茄科番茄属（以前称为番茄属）植物，长期以来一直是植物遗传学的经典模式物种之一。最近，茄科植物已成为进化基因组学的一个模式，多个EST项目和番茄基因组项目已经启动。作为对解读番茄遗传信息的首个贡献，我们在此展示番茄叶绿体基因组（质体基因组）的完整序列。这个环状基因组的大小为155,461个碱基对（bp），平均AT含量为62.14%。它包含114个基因和保守的开放阅读框（ycfs）。与先前测序的烟草和颠茄的质体DNA进行比较，揭示了茄科家族质体基因组的进化模式，并确定了各个质体基因的不同保守程度。此外，我们发现了几个通过胞嘧啶到尿嘧啶转换的RNA编辑新位点。对这三种茄科植物编辑模式的详细比较突出了叶绿体中RNA编辑位点进化的动态变化。为了评估番茄种内质体基因组的变异水平，对第二个番茄品种的质体基因组进行了测序。两种基因型（在南美洲培育的IPA - 6和在欧洲培育的艾尔莎·克雷格）的比较显示没有核苷酸差异，这表明现代番茄品种的质体基因组即使存在序列变异，也非常少。
