大豆种子老化MDA和4-HNE的含量变化相关性研究

Correlation Studies on MDA and 4-HNE Contents in Soybean Seed Aging

研究了大豆"中豆27"种子在人工老化和自然老化过程中,电导率、丙二醛和4-羟基壬烯醛(4-hydroxy-(E)-2-nonenal,4-HNE)含量,4-HNE的组织特异性积累及其与合成清除酶系统相关的基因表达调控差异,以探寻大豆种子的老化生理指标。结果表明,伴随着老化,大豆种子萌发率逐渐降低,浸泡液电导率逐渐增大;丙二醛含量升高;4-羟基壬烯醛(4-hydroxy-(E)-2-nonenal,4-HNE)在低活力干种子(萌发率10%)中积累量显著升高,且在人工老化和自然老化至中等活力干种子(萌发率50%～80%)和吸胀20 h的种子中,前者含量皆高于后者;免疫组化染色结果表明,老化至萌发率80%的种子中的4-HNE积累量则是自然老化种子明显高于人工老化种子。同时,老化诱导4-HNE的合成,但与4-HNE清除相关的乙醇脱氢酶(alcohol dehydrogenase)和谷胱甘肽-S-转移酶(glutathione-S-transferase)基因在人工老化下表达水平显著高于自然老化,即2种老化条件下种子中4-HNE的清除可能存在差异。因此,丙二醛和4-HNE累积与种子活力呈负相关关系,可作为种子老化程度的生理指标。

To explore the physiological indicators reflecting soybean seed aging,in this paper,soybean variety“Zhongdou 27”was used as materials to measure the changes of electrical conductivity of seed soak solution,the content of MDA(malondialdehyde)and 4-HNE(4-hydroxy-(E)-2-nonenal),tissue specific accumulation of 4-HNE,and the differences in the expression and regulation of genes relative to 4-HNE formation and scavenging enzyme system under natural aging and artificial aging.The results showed that the germination rate of seed soak solution was decreased gradually,While the electrical conductivity and Malondialdehyde(MDA)content were increased.The accumulation of 4-hydroxy-(E)-2-nonenal(4-HNE)was increased significantly in low-activity dry seeds(germination rate 10%)during the artificial and natural aging process.The content of artificial and natural aging to medium vigor dry seeds(germination rate 50%-80%)and imbibition seeds for 20 h were higher than that of the latter.The content of 4-hydroxy-(E)-2-nonenal Immunohistochemical staining showed that the accumulation of 4-HNE in the seeds aged to 80%germination rate were significantly higher than that of the artificially aged seeds.At the same time,aging induces the synthesis of 4-HNE,but genes of alcohol dehydrogenase and glutathione-S transferase associating with scavenging 4-HNE expressed significantly higher in the artificially aged seeds than that of naturally aged seeds.That meant the scavenging of 4-HNE in seeds under the two aging conditions may be different.Therefore,MDA and 4-HNE accumulation were negatively correlated with seed vigor.It could be used as physiological indicators of seed aging.