Li B, Foley M E
Department of Botany & Plant Pathology, Purdue University, West Lafayette, IN 47907-1155, USA.
Plant Mol Biol. 1995 Nov;29(4):823-31. doi: 10.1007/BF00041171.
To analyze the patterns of gene expression associated with seed dormancy in wild oat (Avena fatua), we have isolated cDNA clones corresponding to genes that are differentially expressed in dormant and afterripened line M73 embryos. Gene transcripts of these clones were maintained in embryos of imbibed dormant caryopses, but declined rapidly in afterripened embryos after imbibition. GA3 treatment of dormant caryopses, which breaks dormancy, could lower the transcript levels in dormant embryos. When the germination of afterripened caryopses was inhibited by high temperature (35 degrees C), the decline in abundance of the transcripts in afterripened embryos was arrested. These genes were expressed to various degrees in water-stressed, but not in unstressed, 7-day-old seedlings. The expression of the genes was also ABA-inducible in afterripened embryos. The expression patterns in non-dormant line SH430 wild oat were similar to those of afterripened M73. DNA sequence analyses indicated that some of the cDNA clones encode LEA (late embryogenesis-abundant) proteins and aldose reductase. The significance of the expression of these genes in maintaining seed dormancy or longevity is discussed.
为了分析与野燕麦（Avena fatua）种子休眠相关的基因表达模式，我们分离了与在休眠和后熟的M73胚中差异表达的基因相对应的cDNA克隆。这些克隆的基因转录本在吸胀的休眠颖果的胚中得以维持，但在吸胀后的后熟胚中迅速下降。用GA3处理打破休眠的休眠颖果，可以降低休眠胚中的转录本水平。当后熟颖果的萌发被高温（35摄氏度）抑制时，后熟胚中转录本丰度的下降就会停止。这些基因在水分胁迫的7日龄幼苗中有不同程度的表达，但在未受胁迫的幼苗中不表达。这些基因的表达在后熟胚中也受脱落酸诱导。非休眠品系SH430野燕麦中的表达模式与后熟的M73相似。DNA序列分析表明，一些cDNA克隆编码胚胎发育晚期丰富蛋白（LEA）和醛糖还原酶。本文讨论了这些基因的表达在维持种子休眠或寿命方面的意义。
