棒叶落地生根对干旱与复水的生理响应

Physiological Response of Kalanchoe tubiflora Leaves to Drought Stress and Rewatering

摘要:

为探讨棒叶落地生根（Kalanchoe tubiflora）耐旱的机制，在干旱与复水条件下，对其叶片的一些生理生化指标进行了测定。结果表明，随干旱时间延长，棒叶落地生根叶片中O₂^·生成速率增大，H₂O₂ 含量升高，导致脂质过氧化产物MDA 含量增高；同时SOD 活性升高，CAT 活性降低；可溶性糖与脯氨酸含量增加，但复水后这些指标均恢复到干旱前的水平。这说明棒叶落地生根能够耐受干旱环境是通过积累渗透调节物质，提高活性氧的清除能力，从而减少氧化胁迫造成的伤害。

Abstract:

In order to understand the mechanism of drought tolerance in Kalanchoe tubiflora, some physiological and biochemical indexes in K. tubiflora leaves were determined under drought and rewatering conditions. The results showed that O₂^· production rate, and H₂O₂ and malonaldehyde ( MDA) content increased with prolonged droughts, and the contents of soluble sugar and proline, as well as SOD activity enhanced, while CAT activity reduced. All of these could restore to the level before drought under rewatering treatment. In conclusion, it was suggested that K. tubiflora tolerate drought stress by accumulation of osmoregulators, improving capacity of active oxygen scavenging, thus reducing the damage caused by oxidative stress.