【作者】 耿明建； 朱建华； 吴礼树； 曹享云； 刘武定；

【Author】 Geng Ming-jian, Zhu Jian-hua, Wu Li-shu, Cao Xiang-yun Liu Wu-ding (Laboratory of Trace elements. Huazhong Agricultural University, Wuhan 430070. China)

【机构】 华中农业大学微量元素研究室；

【摘要】 尽管越来越多的证据表明硼对维持原生质膜结构和功能完整性具有重要作用,但至今硼与原生质膜作用的机制仍不清楚。本文在土培条件下以不同硼效率棉花品种为材料,测定苗期叶片膜伤害、膜脂肪酸组分、保护酶活性及多胺化合物含量,研究硼通过自由基代谢对膜特性的影响及不同棉花基因型表现的差异,并探讨多胺化合物在该生理过程中的作用。结果表明,遭受缺硼胁迫时,两棉花品种叶片膜透性和丙二醛含量均增加,膜脂肪酸不饱和度下降,保护酶SOD、POD、CAT活性降低,但硼高效品种变化幅度比低效品种小,说明缺硼影响棉花苗期叶片自由基代谢并引起膜质过氧化,低效品种受伤害程度更大。缺硼还导致两品种叶片中腐胺(Put)含量显著降低,高效品种降低幅度12.8%明显低于低效品种的23.2%。但缺硼时,低效品种叶片中的亚精胺(Spd)、精胺(Spm)含量和多胺总量(Put+Spd+Spm)与正常硼处理比较仅有升高趋势,而高效品种却显著或极显著增加,其Spd、Spm和多胺总量分别增加1.89倍、0.61倍和0.45倍。推测硼高效品种在缺硼条件下保持较高的多胺含量是其保护酶活性较高、膜受伤害程度较轻的原因。更多还原

【Abstract】 Two cotton cultivars with different boron efficiency were cultured in pot experiments under boron deficient and sufficient condition. Some physiological indexes concerning membrane lipid peroxidation and protection in cotton leaves were determined at seedling stage. When two cotton cultivars were suffered from boron deficiency, malonyl dialdehyde(MDA) content and membrane permeability in their leaves were increased, the activity of protective enzymes such as superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT), the double bond index and the ratio of unsaturated to saturated fatty acid were decreased, however, the increase or decrease degree of boron efficient cultivar was less than that of inefficient one. The putrescine content was significantly reduced by boron deficiency in both cultivars, but with higher intensity in boron inefficient one. Boron deficiency caused a marked increase of the content of spermidine(Spd), spermine(Spm) and Spd+Spm+Put in boron efficient cultivar, but only an upward trend in the inefficient cultivar. The paper suggested that higher polyamines content in boron efficient cultivar under boron deficiency condition resulted in higher activity of protective enzymes, which might remain membrane function integrity.更多还原