High oleate mutants of brassica napus produced by ems inducement | EMS诱变甘蓝型油菜获得高油酸突变体

Китайский. 摘　　要：用0.4%EMS诱变甘蓝型油菜NJ7982种子,从M2代筛选得到1个油酸含量76.15%的突变株（M2-2080）,M3代该突变体的油酸含量也达到了75.0%（M3-2080-1）。对高油酸突变体M3-2080-1和野生型BnFAD2基因进行克隆,分析突变体油酸含量高的原因。序列表明,高油酸突变体中,BnFAD2I基因有63个碱基发生变异,进而导致蛋白质翻译出现终止;BnFAD2II-1基因有41处碱基发生突变,导致15个氨基酸变异,其中处于跨膜区域的＋82氨基酸由丝氨酸突变成脯氨酸,＋157的苯丙氨酸变成亮氨酸,位于疏水区中,还有9处发生突变的氨基酸残基位于α-螺旋区。这些突变位点都发生在油酸脱饱和酶催化中心,进而影响了该酶的活性,可能是导致突变体的油酸含量升高的原因。另外,高油酸突变体及野生型的农艺性状无显著性差异,可作为高油酸育种种质资源。

Английский. Seeds of NJ7982 （Brassica napus L.） were treated with 0.4% EMS, and one high oleate plant （76.15%） was obtained through screening in M2 generation. In its M3 progenies, the highest oleate content reached 75.02% （M3-2080-1）. The BnFAD2 genes of the high oleate mutant M3-2080-1 and the wild type were cloned for revealing the causes of seed high oleate content. Result showed that 63 nucleotides in BnFAD2I gene were mutated, resulting in translation termination of its functional protein; 41 bases in the BnFAD2II-1 gene had been mutated, leading to the change of 15 amino acids, of which include residue Seu-82 and Phe-157 locating in transmembrane region and hydrophobic area respectively were substituted into a Proline and a Leucine, respectively, and 9 amino acids had mutations in the α-helix area. The mutations taking place in the conserved regions considered to be the catalytic center of enzyme, are thought to possibly inactivate the desaturase. There is no significant difference between the high oleate material and the wild type agronomic character means, therefor, it could be used as high oleate germplasm for breeding.