Dalmadi Agnes, Kaló Péter, Jakab Júlia, Saskoi Anikó, Petrovics Tünde, Deák Gábor, Kiss György Botond
Institute of Genetics Agricultural Biotechnology Center, Szent-Györgyi A. St. 4, 2100, Gödöllo, Hungary.
Plant Cell Rep. 2008 Aug;27(8):1271-9. doi: 10.1007/s00299-008-0546-5. Epub 2008 May 27.
In this paper we describe the identification of a gene, MsDWF1 coding for a putative gibberellin 3-beta-hydroxylase (GA3ox), whose natural mutation is conditioning a dwarf growth phenotype in Medicago sativa. The dwarf phenotype could not be complemented with grafting, which indicates that the bioactive gibberellin compound necessary for shoot elongation is immobile. On the contrary, exogenously added gibberellic acid restored normal growth. The genetic position of the Msdwf1 gene was mapped to linkage group 2 (LG2) and the physical location was delimited by map-based cloning using Medicago truncatula genomic resources. Based on the similar appearance and behavior of the dwarf Medicago sativa plants to the pea stem length mutant (le) as well as the synthenic map position of the two genes it was postulated that MsDWF1 and pea Le are orthologs. The comparison of wild type and mutant allele sequences of MsGA3ox revealed an amino acid change in a conserved position in the mutant allele, which most probably impaired the function of the enzyme. Our results indicate that the dwarf phenotype was the consequence of this mutation.
在本文中，我们描述了一个名为MsDWF1的基因的鉴定，该基因编码一种假定的赤霉素3-β-羟化酶（GA3ox），其天然突变导致紫花苜蓿出现矮化生长表型。矮化表型不能通过嫁接得到互补，这表明茎伸长所需的生物活性赤霉素化合物是不可移动的。相反，外源添加赤霉素可恢复正常生长。Msdwf1基因的遗传位置被定位到连锁群2（LG2），其物理位置通过利用蒺藜苜蓿基因组资源进行图位克隆来确定。基于矮化紫花苜蓿植株与豌豆茎长突变体（le）相似的外观和行为，以及这两个基因的同线图谱位置，推测MsDWF1和豌豆Le是直系同源基因。MsGA3ox野生型和突变等位基因序列的比较揭示了突变等位基因中一个保守位置的氨基酸变化，这很可能损害了该酶的功能。我们的结果表明，矮化表型是这种突变的结果。
