陆地棉体细胞胚发育过程中AOS基因家族的表达谱初步分析及功能预测

茉莉酸在调控棉花体细胞胚增殖方面有重要作用,而丙二烯氧化物合酶(AOS)是植物茉莉酸合成途径中的关键酶。作者鉴定出在胚发育过程中表达的AOS基因,这些基因编码区长度均在1500 bp左右,被定位在5条染色体上,有2个基因含有内含子。对其启动子元件分析发现,它们可能受激素和胁迫的调控在体细胞胚胎发生中起作用。荧光定量分析发现,这些基因在棉花不同组织中的表达模式主要分为3类,GhAOS1和GhAOS6在棉花胚发育过程中表达量相对较高,GhAOS2和GhAOS3在棉花愈伤和胚性愈伤中表达量相对较高,GhAOS4和GhAOS5在茎和叶中表达水平相对较高,暗示这些基因的表达有时空特异性,且GhAOS1和GhAOS6可能在棉花胚发育中发挥重要作用。亚细胞定位分析显示,大部分被定位在过氧化物酶体中,可能参与调控光呼吸、体细胞胚成熟和萌发。上述分析为进一步研究AOS基因家族在棉花体细胞胚发育中的功能奠定了基础。

Expression Profile Analysis and Functional Predictions of the AOS Gene Family in Somatic Embryos of Upland Cotton

Allene oxide synthase (AOS) is the key enzyme in the jasmonic acid (JA) biosynthesis pathway. As a class of plant hormones, JA plays an important role in the regulation of plant growth and development, but studies on JAs regulatory role in somatic embryo development are lacking. Here, we identified AOS family members during cotton somatic embryo development. The opening read frames of the six genes are all ~1500 bp, but only two genes contain introns, and the genes are dispersed across five different chromosomes. Based on the expression profile clusters, these genes are mainly divided into three subgroups: the high expression levels of GhAOS1 and GhAOS6 in cotton somatic embryos, the high expression levels of GhAOS2 and GhAOS3 in calli and embryogenetic calli, and the high expression levels of GhAOS4 and GhAOS5 in cotton stems and leaves.The groupings suggest that the genes play different roles during somatic embryo development. Most AOS genes were located in the peroxisome, which may be involved in photorespiration, and somatic embryo germination and maturation. The identification and bioinformatics analyses laid the foundation for the function analysis of the AOS gene family in cotton somatic embryos.