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作 者 ：刘建新；王金成；王瑞娟；贾海燕

期 刊 ：植物研究 2015年 35卷 2期 页码：233-239

关键词：燕麦；NaCl胁迫；KCl；活性氧代谢；渗透溶质；Na+/K+；

Keywords:Avenanude, NaClstress, KCl, activeoxygenmetabolism, osmotica, Na+/K+,

摘 要 ：在温室砂培条件下，研究了不同浓度KCl（1、10、20、30 mmol·L^-1）对120 mmol·L^-1 NaCl胁迫下‘定莜6号’燕麦植株生长、叶片活性氧代谢和渗透溶质积累的影响。结果表明：（1）与1 mmol·L^-1 KCl处理相比，10和20 mmol·L^-1 KCl显著提高了NaCl胁迫下燕麦幼苗的鲜重、干重和相对含水量;叶片超氧阴离子、H₂O₂、丙二醛和谷胱甘肽含量及质膜相对透性明显下降;超氧化物歧化酶、过氧化物酶和抗坏血酸过氧化物酶活性显著提高，其中20 mmol·L^-1 KCl的作用大于10 mmol·L^-1 KCl；过氧化氢酶活性和抗坏血酸含量则变化不大，而30 mmol·L^-1 KCl却加剧了盐胁迫伤害。（2）10和20 mmol·L^-1 KCl处理的燕麦叶片可溶性蛋白质、可溶性糖和脯氨酸的含量显著高于其它处理，而游离氨基酸含量与1 mmol·L^-1 KCl处理相比明显下降，有机酸含量则保持相对稳定。（3）随着KCl浓度提高，燕麦叶片K⁺/Na⁺增大，质膜H⁺-ATP酶活性先升后降。上述结果表明，以Na⁺/K⁺ 6∶1施用钾肥可通过提高活性氧清除能力和渗透溶质积累有效缓解盐胁迫对燕麦幼苗的伤害。

Abstract:We studied the effects of KCl on the plant growth, active oxygen metabolism and osmotica accumulation in Avena nude seedlings (‘Dingyou No.6’) under 120 mmol·L^-1 NaCl stress with sand cultivation in a greenhouse. Compared with 1 mmol·L^-1 KCl, 10 and 20 mmol·L^-1 KCl on A.nude seedlings, respectively, could significantly increase its weights of fresh and dry, relative water content, as well as its leaf activities of superoxide dismutase, peroxidase and ascorbate peroxidase, but decrease its the contents of O^·₂, H₂O₂, malondialdehyde and glutathione and membrane relative permeability under the NaCl stress. Moreover, the effect of 20 mmol·L^-1 KCl was higher than that of 10 mmol·L^-1, but there were no significant effects on the catalase activity and ascorbic acid content, however, the damage of salt stress was significantly increased when KCl concentration was up to 3.0 mmol·L^-1. The contents of soluble protein, soluble sugar and proline in A.nude leaves were significantly higher than that of others, when KCl concentration was 10 and 20 mmol·L^-1, but its free amino acids contents were significantly lower than that of 1 mmol·L^-1 KCl, and little variation in content of organic acids. The K⁺/Na⁺ ratio in leaves of A.nude seedlings under NaCl stress increased significantly, and the plasma membrane H⁺-ATPase activities demonstrated a hump-shaped curve with the increase of KCl. Therefore, the ratio 6∶1 of Na⁺/K⁺ could alleviate the negative impact of salt stress on A.nude seedlings through improving the ability of scavenging reactive oxygen species and osmotica accumulation.

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