硼对不同硼效率棉花品种苗期叶片膜脂过氧化和多胺含量的影响

Effects of boron on membrane lipid peroxidation and polyamines content in leaves of two cotton cultivars with different boron efficiency at seedling stage

土培条件下研究缺硼对不同硼效率棉花品种苗期叶片膜伤害、保护酶活性及多胺化合物含量的影响。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。缺硼还导致两品种叶片中腐胺 (Put)含量显著降低 ,而低效品种降低幅度更大 ,但缺硼使高效品种叶片中精胺 (Spm)、亚精胺 (Spd)含量及多胺总量 (Spd +Spm +Put)显著升高 ,低效品种仅有升高趋势。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之一。

Two cotton cultivars with different boron efficiency were cultured in pot experiments under boron deficient and sufficient conditions. 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(Put) 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 results 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.