小桐子幼苗在空气干旱胁迫下的水分状况变化与渗透调节物质响应差异

目的]研究小桐子幼苗在空气干旱胁迫下的水分状况变化与渗透调节物质响应差异，以更好地理解其抗旱性机制。方法]以培养12d的小桐子幼苗为材料，在25℃／20℃（昼／夜）、16h光照、相对湿度75％的人工气候箱中进行空气干旱处理，测定小桐子水势、渗透势，以及可溶性糖、脯氨酸、甜菜碱含量变化。结果]空气干旱处理导致小桐子叶片水势、渗透势显著下降，膨压丧失。小桐子叶片和茎秆中可溶性糖、脯氨酸和甜菜碱含量不同程度地显著上升。结论川、桐子叶和茎中有机渗透调节物质对干旱胁迫的响应存在明显差异，总体而言，叶片对干旱的响应大于茎秆。

Changes of Water Status and Different Responses of Osmoregulants in Jatropha curcas L. Seedlings to Air-drought Stress

Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress, to better understand mechanisms of drought resistance in Jatropha curcas L. Method] The 12-day-old J. curcas seedlings were held in a climate chamber at 25/20 ℃(day/night), 16 hours illumination, and 75% of relative humidity for air-drought treatment, and the changes of water potential, osmotic potential and the content of soluble sugar, proline, betaine were measured. Result] Water potential and osmotic potential in leaves of J. curcas seedlings dropped significantly, expansion pressure lost during air-drought stress, and the contents of osmoregulants soluble sugar, proline and betaine rose significantly to different extent in the leaves and stems. Conclusion] Osmoregulants in the leaves and stems respond differently to air-drought stress, and in general leaves are much more responsive to the drought than stems of J. curcas seedlings.