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促分裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)在活性氧(reactive oxygen species,ROS)信号转导过程中起重要作用,然而MAPKs途径相关基因在种子老化过程中的表达变化尚不清楚。本文以玉米杂交种‘郑单958’种子为材料,研究了人工老化处理(温度45℃、RH 100%)对玉米种子活力及生理特性的影响,并用数字基因表达谱技术研究老化相关MAPKs途径基因表达变化。结果表明,随着老化时间的延长,种子活力指数迅速下降;种胚内超氧阴离子产生速率在老化处理第3天达到高峰,随后下降;ABA含量表现为下降趋势;种子老化过程中检测到MAPK途径相关基因53个,其中差异表达的有25个(上调基因14个,下调基因11个);对响应ROS的MAPK基因启动子区域(上游2 kb)碱基序列分析发现,该区域分布有ABRE、DRE/CRT等多种ABA的顺式作用元件;对MEKK1-MKK4/MKK5-MPK3/MPK6途径基因表达分析发现,MKK4(GRMZM5G878379)基因上调表达,而受ROS激活的Zm MPK6(AC188023.3_FG011)基因下调,表明MEKK1-MKK4/MKK5-MPK3/MPK6途径信号传递可能受阻。因此,推测MAPK信号转导途径的破坏可能是种子劣变的重要原因之一。
Mitogen-activated protein kinases (MAPKs) play an important role in the signal transduction of reactive oxygen species (ROS). However, the changes of MAPKs pathway-related genes during seed aging are not clear . In this study, the effects of artificial aging treatment (temperature 45 ℃, RH 100%) on the seed vigor and physiological characteristics of maize hybrids Zhengdan 958 were studied. Aging gene MAPKs pathway was studied by digital gene expression profiling Change of expression The results showed that the seed vigor index decreased rapidly with the aging time. The generation rate of superoxide anion in seed embryos peaked on the third day after aging and then decreased. The ABA content showed a downward trend. The MAPK There were 53 pathway-related genes, of which 25 were differentially expressed (14 up-regulated genes and 11 down-regulated genes). The analysis of the base sequence of the MAPK gene promoter region (2 kb upstream) that responded to ROS revealed that ABRE , DRE / CRT and other ABA cis-acting elements. The gene expression analysis of MEKK1-MKK4 / MKK5-MPK3 / MPK6 pathway found that MKK4 (GRMZM5G878379) gene was up-regulated while ROS-activated Zm MPK6 (AC188023.3_FG011) Gene downregulation, suggesting that MEKK1-MKK4 / MKK5-MPK3 / MPK6 pathway signaling may be blocked. Therefore, it is speculated that the destruction of MAPK signal transduction pathway may be one of the important reasons for seed deterioration.