NaCl处理对小果白刺叶片主要渗透调节物质和激素水平的影响

Effects of NaCl Stress on Main Osmoregulation Substance and Hormones Contents of Nitraria sibirica Pall. Leaves

以1年生小果白刺幼苗为试验材料,采用水培处理法,研究不同处理时间(1 d和14 d)及不同浓度的NaCl(0、100、200、300、400 mmol·L^(-1))对小果白刺叶片中可溶性糖、氨基酸类等主要渗透调节物质及ABA(脱落酸)、IAA(生长素)、GA(赤霉素)、ZR(玉米素核苷)等植物内源激素变化的影响,探讨小果白刺对NaCl处理的生理代谢机制。结果表明:小果白刺叶片中可溶性糖质量分数在NaCl处理1 d时,随着NaCl的浓度的升高逐渐减少;在NaCl处理14 d时,随着NaCl摩尔浓度的升高可溶性糖质量分数逐渐增加。小果白刺叶片中脯氨酸质量分数和总氨基酸质量摩尔浓度在NaCl处理1 d时具有相似的变化趋势;NaCl处理14 d时,脯氨酸质量分数随NaCl浓度的升高而增加,而总氨基酸质量摩尔浓度只有在D处理(400 mmol·L^(-1)NaCl)时高于对照。ABA质量分数随着NaCl浓度的升高及处理时间的延长而增加。IAA和ZR质量分数在NaCl处理下,具有相似变化趋势,随NaCl处理时间的延长而减少,随NaCl浓度的升高而表现为先增加后减少,在A处理(100 mmol·L^(-1)NaCl)时,IAA和ZR质量分数最高。GA质量分数随NaCl处理浓度的升高而不断增加,在低浓度处理时增量较小,而高浓度处理增量较大;经长时间NaCl处理后,GA质量分数维持在相对较高水平。因此,小果白刺对盐渍环境的生理代谢响应机制是通过ABA质量分数的增加及IAA质量分数的减少等调控生理代谢和生长,改变正常代谢途径,进而促进可溶性糖及脯氨酸等主要渗透调节物质的积累进行渗透调节。

We investigated the physiological and metabolic mechanism of Nitraria sibirica Pall. under NaCl stress. One-year seedlings of N. sibirica were treated in solution cultures containing 0, 100, 200, 300, and 400 mmol·L^-1 of NaCl. Leaves were sampled on the first and fourteenth days after treatment to evaluate the main osmoregulation substance(soluble sugar、 proline and amino acids) and endogenous hormones(ABA, IAA, GA and ZR) contents. The content of soluble sugar in N. sibirica leaves gradually decreased with the increase of NaCl concentration after 1-d treatment, while the soluble sugar contents added with the increase of NaCl concentration after 14-d treatment. The content of proline and amino acids have a similar varying tendency after 1-d treatment. The proline contents increased with the augmentation in the concentration of NaCl treatment, while the amino acids contents under 400 mmol·L^-1 NaCl treatment was higher than treated without salt treatment after 14 d. ABA contents increased with the augmentation in the concentration of NaCl treatment and the prolongation of treatment time. The content of IAA and ZR have a similar varying tendency under NaCl treatment, which decreased with the prolongation of treatment time. However, the contents of IAA and ZR increased first and then decreased with the increase of concentration, and the contents were highest in 100 mmol·L^-1 NaCl treatment. GA content increased with the increase of NaCl treatment concentration. The increment of GA content in low concentration treatment was small, while that in high concentration treatment was large. After a long period of NaCl treatment, GA quality fraction was maintained at a relatively high level. In conclusion, the physiological metabolic response mechanism of N. sibirica to saline environment may be through the increase of ABA content and the decrease of IAA content to regulate physiological metabolism and growth, change the normal metabolic pathway, and then promote the accumulation of major osmotic adjustment substances such as soluble sugar and proline for osmotic regulation.