水稻DNA损伤修复同源基因纯合突变系的鉴定

在长期的进化过程中,生物逐步形成了应对各种DNA损伤的修复机制,以保护基因组的完整性,减轻或消除DNA损伤的影响。本研究通过同源搜索找到了与DNA损伤修复相关水稻同源基因,在水稻插入突变体库中搜索出插入突变系,并成功引进了其中的26份T1代突变材料。通过对插入位点的分子鉴定和进一步培育,获得了14份涉及8个水稻DNA损伤修复同源基因的T3代纯合插入突变系,并对其进行了初步的遗传分析和表型考察。这些纯合突变系涉及的水稻基因可能在DNA错配修复(Os02g0592300、Os09g0407600、Os10g0509000)和碱基切除修复(Os02g0465112、Os06g0643600、Os05g0567500、Os04g0673400、Os09g0420300)中发挥重要作用。与亲本相比,除1份材料外,其他纯合突变体系及其野生型姐妹系的结实率均有显著降低;某些纯合突变系的千粒重与亲本相比有显著下降。这些水稻DNA损伤修复基因突变系的育成为开展水稻DNA修复的遗传学和分子生物学研究以及培育抗逆水稻提供了珍贵的实验材料。

IDENTIFICATION OF HOMOZYGOUS MUTANT LINES OF GENES INVOLVED IN DNA DAMAGE REPAIR IN RICE

In the process of biological evolution,organisms have developed DNA repair mechanisms responding to various types of DNA damage to protect genome integrity and remove or minimize the effect of DNA damage.Through homolog search,the rice genes homologous to DNA damage repair genes were identified.Mutant lines with the genes inserted either by a T-DNA or Tos17 were searched in mutant databases,and 26 T1 lines were successfully introduced.Molecular analyses of insertion sites enabled the identification of 14 homozygous T3 mutant lines that involved 8 DNA damage repair genes.Preliminary genetic and agronomic trait analyses were also performed.The rice genes that are disrupted in these 14 mutant lines probably play roles in DNA mismatch repair(Os02g0592300,Os09g0407600,Os10g0509000) and base excision repair(Os02g0465112,Os06g0643600,Os05g0567500,Os04g0673400,Os09g0420300).Compared with wild type parents,the seed set of 13 mutant lines of both homozygous mutant plants and wild type siblings was significantly reduced,while some of them had reduced grain weight.These mutant lines should serve as valuable materials for genetic and biological studies on DNA damage repair and improvement of abiotic stress tolerance in rice.