Abstract: In order to explore the influence of cholinium-based ionic liquids residue produced during straw pretreatment on maize seeds germination under drought stress, the typical maize variety Zhengdan 958 was used as the object of study, and 13% polyethylene glycol -6000 (PEG) was used to simulate drought stress environment. Taking seeds germination parameters, root length, shoot length and antioxidant enzyme activity of embryo as indicators, effects of 200 mg·L^-1 cholinium fatty acid ionic liquids (cholinium adipic acid, cholinium octanedioic acid) and cholinium amino acid ionic liquids (cholinium valine, cholinium threonine, cholinium aspartic acid, cholinium asparagine) soaking treatment on the germination of maize seeds under drought stress were studied. The results showed that under drought stress, soaking seeds of cholinium adipic acid and cholinium octanedioic acid significantly increased the germination index of maize seeds, while soaking seeds with cholinium aspartic acid and cholinium asparagine significantly increased the germination potential of maize seeds. In addition, soaking seeds with cholinium ionic liquid promoted the growth of maize root and shoot. The shoot length of soaking seeds with cholinium threonine increased most obviously by 48.2%. The root length increased significantly by 26.7% after soaking seeds with cholinium aspartic acid. Under drought stress, maize embryos soaked with different cholinium valine and cholinium threonine increased POD and CAT activity significantly, while the contents of MDA and H₂O₂ were decreased significantly. The results showed that cholinium ionic liquids treatment could alleviate oxidative stress by increasing the antioxidant enzyme activity of maize embryos, reducing the content of MDA and H₂O₂, and promoting the germination of maize seeds and the growth of seedlings under PEG simulated drought stress. Therefore, cholinium ionic liquid is expected to be used as a plant growth regulator, which provides a feasible way for the utilization of cholinium ionic liquid residue.

Key words: cholinium-based ionic liquids, drought stress, maize, germination

摘要： 为探究秸秆预处理过程中产生的胆碱类离子液体残液对干旱胁迫下玉米种子萌发的影响,以典型农作物玉米(Zea mays L.)为研究对象,使用13%聚乙二醇-6000(PEG)模拟干旱胁迫,以种子萌发参数、根芽长、种胚抗氧化酶活性为指标,研究200 mg·L^-1胆碱脂肪酸离子液体(胆碱己二酸、胆碱辛二酸)和胆碱氨基酸离子液体(胆碱缬氨酸、胆碱苏氨酸、胆碱天冬氨酸、胆碱天冬酰胺)浸种处理对PEG模拟干旱胁迫下玉米种子萌发的影响。结果表明,PEG模拟干旱胁迫下,胆碱己二酸、胆碱辛二酸浸种处理显著提高了玉米种子的发芽指数,胆碱天冬氨酸、胆碱天冬酰胺浸种处理显著提高了种子的发芽势。另外,胆碱类离子液体浸种均促进了干旱胁迫下玉米根芽的生长,其中胆碱苏氨酸浸种处理下芽长增加最显著,增加48.2%;胆碱天冬氨酸浸种处理下根长增加最显著,增加26.7%。在PEG模拟干旱胁迫条件下,不同胆碱脂肪酸和胆碱氨基酸浸种处理提高了种胚中过氧化物酶(POD)和过氧化氢酶(CAT)活性,且丙二醛(MDA)和过氧化氢(H₂O₂)含量均显著下降。综上,胆碱类离子液体浸种处理可能通过提高PEG模拟干旱胁迫下玉米种胚的抗氧化酶活性,降低MDA和H₂O₂含量,缓解氧化胁迫,促进PEG模拟干旱胁迫下玉米种子的萌发与萌发后根芽的生长。胆碱类离子液体有望作为作物生长调控物质,这为胆碱离子液体残液的利用提供了可行的途径。

关键词: 胆碱类离子液体, 干旱, 玉米, 萌发