DCPTA对盐胁迫下玉米叶片渗透调节生理生化特征影响

Effect of DCPTA on the physiological and biochemical characteristics of osmotic adjustment in maize seedling leaves under salt stress

为明确DCPTA提高玉米幼苗耐盐性生理生化机制,采用Hoagland营养液水培试验,以‘先玉335’和‘丰禾1号’两类不同耐盐性玉米品种为材料,研究15 mg·L-1DCPTA对150 mmol·L-1Na Cl胁迫下玉米幼苗生物量、叶片相对含水量、渗透调节及细胞膜稳定性的影响。结果表明,DCPTA显著增加盐胁迫下玉米幼苗鲜重、干重及株高,缓解盐胁迫对幼苗生长的抑制。盐胁迫下DCPTA处理的玉米叶片可溶性糖和可溶性蛋白含量增加,脯氨酸含量降低,叶片相对含水量提高。施用DCPTA后,与单一盐胁迫相比,‘先玉335’叶片MDA含量和相对电导率分别降低26.4%和26.0%,‘丰禾1号’分别降低31.3%和33.5%。外源DCPTA通过提高植株渗透调节能力,维持植株水分平衡,保护细胞膜结构和功能,可减轻盐胁迫对玉米幼苗的伤害。DCPTA对盐敏感型玉米品种效果更佳。

In order to make clear the physiological and biochemical mechanisms of DCPTA on salt resistant capability of maize seedlings, hydroponic experiments were performed with two different salt tolerance varieties ＇Xianyu 335＇ and ＇Fenghe No.1＇ to investigate the effects of 15 mg · L^-1 DCPTA on biomass, relative water content, osmotic adjustment and cell membrane stability of maize seedings under 150 mmol. L^-1 NaCl stress. The results showed that, DCPTA significantly increased fresh weight, dry weight and plant height of maize seedlings and alleviated growth inhibition under the condition of salt stress. DCPTA treatment under salt stress led to a increase in soluble sugar and soluble protein content, a decrease in proline content and an improvement in relative water content of maize leaves. The MDA content and relative conductivity of ＇Xianyu 335＇ under DCPTA application were 26.4% and 26.0% lower than those under salt treatment, respectively, ＇Fenghe No.l＇ were 31.3% and 33.5% lower, respectively. Exogenous DCPTA alleviated the salt stress damage to maize seedlings by enhancing the osmotic adjustment ability maintaining the water balance and protecting cell membrane structure and function of seedling leaves DCPTA has a better effect on salt-sensitive maize variety.