Effects of PEG6000 stress on growth and alkaloid content of Catharanthus roseus seedlings | PEG6000对长春花幼苗期的胁迫效应和生物碱含量的影响

Chinese. 在温室培养条件下，研究不同体积分数聚乙二醇（polyethylene glycol，PEG）6000处理下长春花幼苗期的胁迫效应以及对文多灵、长春质碱和长春碱等生物碱含量的影响。结果表明：相同体积分数PEG6000处理下，随着胁迫时间的延长，叶片相对含水量呈先降低后上升的趋势，脯氨酸含量呈缓升到急升的趋势。综合二因素的差异显著分析，选择35%（V/V）PEG6000模拟干旱胁迫处理长春花，与对照相比，干旱胁迫的叶片中的过氧化物酶活性先增强后降低；文多灵（vindoline，VIN）含量先升高后下降，长春质碱（catharanthine，CAT）含量先下降后升高，而长春碱（vinblastine，VBL）含量逐渐升高，24h达到峰值为0.168 0±0.003 6mg/g（鲜质量）。

English. The effects of PEG6000 on the growth and the contents of vindoline (VIN), catharanthine (CAT) and vinblastine (VBL) of Catharanthus roseus seedling were investigated using soil cultivation in the greenhouse. The results showed that the developing trend of the relative water content (RWC) was declining and rising. The developing trend of proline (Pro) content was increasing slowly and increasing quickly with the development of time under the same concentration PEG6000 stress. Combining and optimizing various conditions, 35% (V/V) PEG6000 stress on leaves of C. roseus was established. Contrasting with the control, the peroxidase activities increased gradually first and then decreased. Vindoline content decreased gradually then increased while catharanthine content increased gradually then decreased. Vinblastine content increased and reached the highest 0.168 0±0.003 6 mg/g (FW) on the 24th hour. The results showed that peroxidase activities could regulate the transform from monomeric indole alkaloids to bis-indole alkaloids under the osmosis stress.