小麦旗叶老化期间蛋白水解酶活力的变化

研究了扬麦五号及野生一粒小麦旗叶老化期间蛋白水解酶活力的变化。结果表明： 两品种小麦旗叶全展后蛋白水解酶活力变化均可明显区分为低值稳定期和速升期， 分别对应于叶绿素的缓降期和速降期以及光合速率的高值持续期和速降期。低值稳定期， 蛋白水解酶活力在较低水平范围内波动； 速升期， 酶活力迅速升高。同时， 总可溶蛋白和 Ｒｕ Ｂ Ｐ Ｃａｓｅ 蛋白含量在低值稳定期内下降相对较缓； 速升期则迅速下降。暗示蛋白水解酶与光合功能衰退和叶片老化密切相关。

Changes of the activity of proteases in wheat flag leaves during aging

Protease activity was assayed in the wheat flag leaves(T.aestivum L.var.Yangmai No.5 and T.boeoticum Boiss).The results showed that changes of protease activities included two phases,relatively steady phase of low protease activity(RSPP)and rapid increase phase of protease activity(RIPP),which consisted with relatively steady phase(RSP)and sharp fall phase(SFP)of chlorophyll content,photosynthetic active duration(PAD)and photosynthetic sharp fall duration(PSF)respectively.During RSPP,protease activities kept at low level,and during RIPP,increased rapidly.The phenomenon accorded with the various parameters of leaf aging,namely the decline in chl,total soluble protein,RuBPCase and photosynthesis.All of these indicated that the proteases might be positively correlated with decline of phototsynthetic capability and wheat flag leaf aging.