甘薯愈伤组织对干旱胁迫和盐胁迫的生理反应对比

研究干旱胁迫和盐胁迫对“芦选一号”。日‘薯愈伤组织可溶性蛋白、可溶性糖、脯氨酸含量、SOD活性等的影响，从而在细胞水平上探讨甘薯抵御渗透胁迫的生理机制。并分析甘薯细胞对干旱处理（PEG-6000）和盐处理（NaCl）的反应差异。结果表明，可溶性蛋白质含量在干旱胁迫下缓慢升高，在轻度和中度盐胁迫的生长前期和中期有较大幅度的上升。但后期下降，表明短时间盐胁迫下，Na^＋可能促进可溶性蛋白的合成；MDA在重度干旱胁迫下的含量显著低于重度盐胁迫，而SOD活性显著高于盐胁迫。表明在盐胁迫下细胞膜透性增加的主要原网是膜脂过氧化作用。干旱处理则是PEG-6000脱水的直接结果；重度干旱胁迫下，可溶性糖含量在短期内迅速升高，然后下降，而脯氨酸含量则在胁迫中后期迅速上升。脯氨酸可能有补偿可溶性糖含量降低的作用。

Physiological responses of sweet potato callus to drought and salt stress

With sweet potato "Lu Xuan 1" as test material,this paper studied the effects of drought-and salt stress on the callus soluble protein,soluble sugar and proline contents and SOD activity,aimed to understand the physiological mechanisms of sweet potato in resisting osmotic stress at cell level,and to analyze the difference of callus responses to drought-and salt stress.The results showed that soluble protein content had a slow increase under drought stress,and increased markedly at the early and middle stages of slight and moderate salt stress but decreased then,suggesting that Na~+ was likely to promote the synthesis of soluble protein under short period salt stress.MDA content was markedly lower under severe drought stress than under severe salt stress,while SOD activity was in adverse,indicating that the increase of cytoplasm membrane permeability was resulted from the lipid peroxidation under salt stress and the dehydration by PEG-6000 under drought stress.Under severe drought stress,soluble sugar content had a fast increase within a short period of time and decreased then,while proline content increased fast at the middle and later stages of this stress,indicating that proline could probably compensate the decrease of sugar content.