盐胁迫对菊苣幼苗脯氨酸积累及其代谢途径的影响  

Effects of NaCl Stress on Proline Accumulation and Metabolic Pathways of Chicory(Cichorium intybus L.) Seedlings

作　　者：王康[1,2] 刘艳香[1] 董洁[3] 周禾[2] 董宽虎[1] 

机构地区：[1]山西农业大学动物科技学院,太谷山西030801 [2]中国农业大学动物科技学院草地研究所,北京100193 [3]中国农业科学院北京畜牧兽医研究所,北京100193

出　　处：《草地学报》2011年第1期102-106,共5页Acta Agrestia Sinica

基　　金："十一五"国家科技支撑计划课题"退化草地植被恢复与重建关键技术研究"(2007BAD56B01)资助

摘　　要：以菊苣(Cichoriumintybus L.)为材料,研究不同浓度NaCl处理对菊苣幼苗体内脯氨酸代谢的影响,以期揭示菊苣中脯氨酸代谢的基本规律。结果表明:随着处理浓度的增加,菊苣中鸟氨酸δ-氨基转移酶(δ-OAT)活性呈上升趋势;吡咯啉-5-羧酸合成酶(P5CS)活性呈现先升后降的趋势;脯氨酸脱氢酶(ProDH)活性呈下降趋势;而脯氨酸含量则显著上升(P<0.05),但高浓度长时间处理后略有降低。研究表明,NaCl胁迫下谷氨酸(Glu)途径和鸟氨酸(Orn)途径对菊苣中脯氨酸的积累均有贡献,低浓度胁迫时P5CS起关键作用的Glu途径占主导地位,高浓度胁迫时δ-OAT起关键作用的Orn途径占主导地位。Proline plays important roles in regulation of osmotic homeostasis,prevention of damages caused by osmotic stresses,scavenging of reactive oxygen species and protection of cell structures.Many plants accumulate proline dramatically under a variety of stress conditions.The regulation of proline accumulation in Chicory seedlings and the activities of key enzymes involved in proline metabolism in response to salinity were studied here.Fifty-day-old seedlings were treated with NaCl（0,100,200,300 and 400 mM） in this experiment.Results show that Ornithine-oxo-acid transaminase（δ-OAT） activity increases;Pyrroline-5-carboxylate synthetase（P5CS） activity initially increases then deccreases,while ProDH activity decreases with increasing NaCl concentration.Proline contents increase significantly（P〈0.05） with increasing salt-stress followed by a declining response during the extending salt-stress period.The data demonstrate that glutamate and ornthine pathways are activated by NaCl.The glutamate pathway is predominant under low-concentration NaCl treatments,and an ornithine pathway is predominant under high-concentration NaCl treatments.

关 键 词：菊苣 脯氨酸代谢 盐胁迫 鸟氨酸δ-氨基转移酶 吡咯啉-5-羧酸合成酶 脯氨酸脱氢酶 

分 类 号：Q945.78[生物学—植物学]