Abstract: The PM-ATPase and 5′-AMPase activity,relative water content(RWC) and malondialdehyde(MDA) content in cells of Bothriochloa ischaemum(L.) Keng were studied in order to explore physiological and biochemical changes under drought stress and rehydration.Results showed that PM-ATPase and 5′-AMPase activities initially increased and then declined under drought stress.The range of PM-ATPase and 5′-AMPase activities in wild types were greater than in cultivated types.The MDA contents increased while the RWC decreased with continuous drought stress.After rehydration,the PM-ATPase and 5′-AMPase activities and MDA content were lower than before,but still higher than control.The RWC of wild type was higher than control and the RWC of cultivation type was lower than control indicating drought resistance of wild species was stronger than cultivated species.

Key words: Bothriochloa ischaemum(L.) Keng, Drought stress, Rewatering, PM-ATPase, 5′-AMPase

摘要： 以白羊草(Bothriochloa ischaemum(L.)Keng)为材料,在干旱胁迫和复水后,通过测定其质膜ATP酶(AT-Pase)活性、质膜5′-核苷酸酶(5′-AMPase)活性,叶片相对含水量(RWC)和丙二醛(MDA)含量的变化来探索其在干旱胁迫和复水后的生理生化变化。结果表明:在干旱胁迫下,白羊草质膜ATPase和质膜5′-AMPase活性呈现先升高后降低的趋势,野生型白羊草的质膜ATPase和质膜5′-AMPase活性变化量较栽培型的大;RWC下降,MDA含量上升。复水后质膜ATPase活性、质膜5′-AMPase活性及MDA含量均下降,但高于断水前,野生型的RWC高于对照,栽培型RWC低于对照,说明干旱胁迫对白羊草造成了不可逆的伤害,对栽培型的伤害大于野生型的。植物的质膜ATPase和质膜5′-AMPase活性随胁迫的加剧而提高,一定程度上可以缓解干旱对白羊草幼苗的胁迫作用,这可能是白羊草抗旱酶促防御机制中的一个重要机制。

关键词: 白羊草, 干旱胁迫, 复水, 质膜ATP酶, 质膜5′核苷酸酶