Rostoks Nils, Schmierer Deric, Mudie Sharon, Drader Thomas, Brueggeman Robert, Caldwell David G, Waugh Robbie, Kleinhofs Andris
Scottish Crop Research Institute, Genome Dynamics, Invergowrie, Dundee, Scotland, UK.
Mol Genet Genomics. 2006 Feb;275(2):159-68. doi: 10.1007/s00438-005-0073-9. Epub 2005 Dec 9.
Barley homolog of the Arabidopsis necrotic (disease lesion mimic) mutant HLM1 that encodes the cyclic nucleotide-gated ion channel 4 was cloned. Barley gene was mapped genetically to the known necrotic locus nec1 and subsequent sequence analysis identified mutations in five available nec1 alleles confirming barley homolog of Arabidopsis HLM1 as the NEC1 gene. Two fast neutron (FN) induced mutants had extensive deletions in the gene, while two previously described nec1 alleles had either a STOP codon in exon 1 or a MITE insertion in intron 2 which caused alternative splicing, frame shift and production of a predicted non-functional protein. The MITE insertion was consistent with the reported spontaneous origin of the nec1 Parkland allele. The third FN mutant had a point mutation in the coding sequence which resulted in an amino acid change in the conserved predicted cyclic nucleotide-gated ion channel pore region. The expression of two pathogenesis-related genes, HvPR-1a and beta-1,3-glucanase, was elevated in two FN necrotic lines. Ten other members of the barley cyclic nucleotide-gated ion channel gene family were identified and their position on barley linkage map is reported.
克隆了拟南芥坏死（疾病损伤模拟）突变体HLM1的大麦同源基因，该基因编码环核苷酸门控离子通道4。大麦基因通过遗传定位到已知的坏死位点nec1，随后的序列分析在五个可用的nec1等位基因中鉴定出突变，证实拟南芥HLM1的大麦同源基因即为NEC1基因。两个快中子（FN）诱导的突变体在该基因中存在广泛缺失，而两个先前描述的nec1等位基因要么在外显子1中有一个终止密码子，要么在内含子2中有一个微型反向重复转座元件（MITE）插入，这导致了可变剪接、移码并产生了一个预测的无功能蛋白。MITE插入与报道的nec1帕克兰德等位基因的自发起源一致。第三个FN突变体在编码序列中有一个点突变，导致保守的预测环核苷酸门控离子通道孔区域中的一个氨基酸发生变化。在两个FN坏死系中，两个病程相关基因HvPR-1a和β-1,3-葡聚糖酶的表达升高。鉴定出了大麦环核苷酸门控离子通道基因家族的其他十个成员，并报道了它们在大麦连锁图谱上的位置。
