月季切花采后花瓣内肽酶活性的变化

 以切花月季耐失水胁迫品种‘萨蔓莎’和中度耐失水胁迫品种‘贝拉米’为试材，研究了采后开花衰老进程中可溶性蛋白质和游离氨基酸含量及内肽酶活性和种类的变化。结果表明，两品种可溶性蛋白质和游离氨基酸含量及内肽酶活性在开花衰老进程中的变化趋势基本一致，但是在量上差异非常明显。可溶性蛋白质含量‘萨蔓莎’低于‘贝拉米’；pH6时，内肽酶活性‘萨蔓莎’低于‘贝拉米’，pH10时相反。两品种花瓣中都存在巯基蛋白酶和丝氨酸蛋白酶。切花月季的失水胁迫耐性可能与其内肽酶活性有关。

Difference of Endopeptidase Activity in Petals between Two Cut Rose Cultivars with Different Tolerance to Water Deficit Stress during Flower Opening and Senescence

Cut rose(Rosa hybrida)'Samantha',a cultivar with strong tolerance to water deficit stress, and 'Belami',a cultivar with middle range tolerance were used to investigate the changes of contents of soluble protein and free amino acid,and endopeptidase activity in petals during flower opening and senescence.The results showed that obvious differences between the two cultivars were obtained in contents of soluble protein and free amino acid,and endopeptidase activity during flower opening and senescence,although the same change patterns were obtained.Soluble protein content was lower in'Samantha'than in'Belami'.Endopeptidase activity was much higher at pH 10,although it was lower at pH 6 in'Samantha'than in'Belami'.However,it was confirmed in petals of the two cultivars that there were two kinds of endopeptidase: mercapto proteinase and serine acid proteinase. The results above suggested that the difference of endopeptidase activity between two cultivars might be related to their tolerance to water deficit stress.