多巴胺引发对盐胁迫下水稻种子萌发及幼苗生长的影响

Effects of Dopamine Priming on Seed Germination and Seedling Growth of Rice Under Salt Stress

【目的】探讨多巴胺(Dopamine,DA)引发对盐胁迫下水稻种子萌发及幼苗生长的影响。【方法】以新疆自育水稻品种新稻17号为研究对象,分别用0(纯水)、0.1、0.5、1、1.5 mg/L的DA溶液(分别用S0、S0.1、S0.5、S1、S1.5表示)引发种子,采用浓度为100 mmol/L的NaCl溶液模拟盐胁迫,以未引发无盐胁迫处理作为对照1(CK),未引发有盐胁迫处理作为对照2(S-CK),研究多巴胺引发对盐胁迫下水稻种子萌发、幼苗生长及生理特性的影响。【结果】与CK相比,盐胁迫下(S-CK)水稻种子的萌发受到明显抑制且萌发速率降低,幼苗长势弱。引发处理不同程度缓解了盐胁迫对种子萌发的抑制,提高发芽率(13.3%~25.8%)和发芽速率,促进幼苗生长;可溶性糖和脯氨酸含量增加(16.4%~51.8%和6.5%~31.2%),超氧化物歧化酶(28.9%~72.7%)、过氧化物酶(15.0%~60.1%)和过氧化氢酶(35.1%~133.0%)活性显著提高,丙二醛(7.1%~26.8%)含量明显降低。表明对种子进行引发处理,通过增强盐胁迫下水稻种子活力,提高幼苗渗透调节物质含量和抗氧化酶活性,降低丙二醛含量,增强了水稻种子及幼苗的耐盐性,其中1.0 mg/L的多巴胺溶液(S1)引发效果优于水引发(S0)。【结论】对于新疆自育水稻品种新稻17而言,1.0 mg/L多巴胺溶液引发能够有效提高其对盐胁迫的抵抗能力,促进种子萌发和幼苗生长。

【Objective】It is of significance to clarify the effects of dopamine priming on rice seed germination and seedling growth under salt stress.【Method】The effects of seed priming on seed germination,seedling growth and physiological characteristics under salt stress were analyzed.Rice(Variety:Xindao 17)seeds were primed with 0(H2O),0.1,0.5,1 and 1.5 mg/L dopamine solution,respectively.Salt stress was simulated with 100 mmol/L NaCl solution.The no-priming and no-salt stress treatment was kept as control 1(CK),and the no-priming with salt stress was kept as control 2(S-CK).【Result】Compared with CK,salt stress(S-CK)obviously slowed down or stopped the germination of rice seeds,and the rice seedlings grew weakly.The priming treatment relieved the inhibitory effect of salt stress on rice seeds germination,speeded up the germination(13.3%-25.8%),promoted seedling growth,increased the contents of soluble sugar(16.4%-51.8%),proline(6.5%-31.2%),and enhanced the activities of SOD(28.9%-72.7%),POD(15.0%-60.1%)and CAT(35.1%-133.0%),decreased the content of MDA(7.1%-26.8%).The results indicated that seed priming could enhance salt tolerance of rice seeds and seedlings by improving the vigor of rice seeds,the activities of antioxidant enzymes and the contents of osmotic regulatory substances,and decreasing the content of MDA.The medium concentration of dopamine solution(S1)was better than water(S0).【Conclusion】The suitable priming solution for Xindao 17 was 1.0 mg/L dopamine,which could effectively enhance salt tolerance of rice seeds,and promote seed germination and seedling growth.