低温胁迫对3份葛种质萌发过程中脯氨酸和抗坏血酸谷胱甘肽循环代谢的影响

Effect of low-temperature stress on proline metabolism and ascorbic acid-glutathione cycle during germination of three Pueraria lobata germplasm lines

为探究不同温度处理对葛种子萌发时脯氨酸代谢和抗坏血酸谷胱甘肽(AsA-GSH)循环的影响,以来自澳大利亚(AUS),以及中国江苏(JS)和湖南(HN)的3份葛种质为研究对象,通过纸上发芽试验,研究不同处理(CK,25℃;LT,15℃;LTI1,10℃;LTI2,0.1%H_(2)O_(2)浸种+10℃)下3份葛种质脯氨酸含量、脯氨酸代谢关键酶活性、AsA-GSH循环代谢中非酶抗氧化剂含量和酶抗氧化剂活性的变化。结果表明,与CK相比,低温胁迫下葛的丙二醛(MDA)、过氧化氢(H_(2)O_(2))含量升高,脯氨酸脱氢酶(ProDH)活性降低,添加H_(2)O_(2)促使脯氨酸、(还原型)抗坏血酸(AsA)、氧化型抗坏血酸(DHA)、(还原型)谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)含量增加,Δ1-吡咯林-5-羧酸合成酶(P5CS)、鸟氨酸转氨酶(OAT)、抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性增强,提高葛藤的耐低温性能。结合隶属函数分析,判定3份葛种质的耐低温性从强到弱依次为HN>AUS>JS。

To investigate the effects of different temperature on proline metabolism and ascorbic acid-glutathione(AsA-GSH)circulatory system during germination of Pueraria lobata seeds,three lines of P.lobata collected from Australian(AUS),and Jiangsu Province(JS),Hunan Province(HN)in China,were subjected to germination tests by using the paper interval method to study the changes in proline content,key enzymes activities of proline metabolism,and contents of non-enzymatic antioxidants and activities of enzymatic antioxidants in the metabolism of AsA-GSH cycle under different treatments(CK,25℃;LT,15℃;LTI1,10℃;LTI2,seed soaking by 0.1%H 2O 2+10℃).The results showed that compared to the CK,low temperature stress increased contents of malondialdehyde(MDA),hydrogen peroxide(H_(2)O_(2))and decreased proline dehydrogenase(ProDH)activity.Application of H_(2)O_(2) increased the contents of proline,ascorbic acid(AsA),dehydro ascorbic acid(DHA),glutathione(GSH),glutathione disulfide(GSSG),and activities ofΔ1-pyrroline-5-carboxylic acid synthase(P5CS),ornithine aminotransferase(OAT),ascorbate peroxidase(APX)and glutathione reductase(GR),hence improved the low-temperature resistance of P.lobata.Based on the membership function analysis,the three P.lobata germplasm lines were ranked as HN>AUS>JS in order of cold-tolerance.