Wu F S, Murry L E
Molecular Biology Group, Zoecon Corporation, Palo Alto, California 94304.
Plant Physiol. 1985 Sep;79(1):301-5. doi: 10.1104/pp.79.1.301.
Proteolytic activity is compared in anther extracts from Petunia parodii fertile and cytoplasmic male sterile lines. It is characterized relative to developmental stage of the anthers, effect of variable incubation times, pH of isolation buffers, and degradation of marker proteins. In fertile anthers, proteolytic activity increases at the end of microsporogenesis and peaks early in microgametogenesis. Degradation is most severe in extracts of fertile anthers and in high molecular weight proteins and reaches its maximum within 20 minutes. Degradation of marker proteins is greatest at pH 5.6 to 8.0 in fertile anther extracts and is eliminated under strong acid conditions (pH 2.8 to 4.0) in both fertile and cytoplasmic male sterile anther extracts. Marker proteins degrade more severely in extracts of fertile anthers; however, the order of substrate sensitivity-myosin > phosphorylase b > bovine serum albumin and ovalbumin > beta-galactosidase-is the same in extracts from fertile and cytoplasmic male sterile anthers.
对矮牵牛可育系和细胞质雄性不育系花药提取物中的蛋白水解活性进行了比较。根据花药的发育阶段、不同孵育时间的影响、分离缓冲液的pH值以及标记蛋白的降解情况对其进行了表征。在可育花药中，蛋白水解活性在小孢子发生末期增加，并在小配子发生早期达到峰值。可育花药提取物中的降解最为严重，高分子量蛋白的降解在20分钟内达到最大值。在可育花药提取物中，标记蛋白在pH 5.6至8.0时降解最为严重，在强酸条件下（pH 2.8至4.0），可育和细胞质雄性不育花药提取物中的降解均被消除。标记蛋白在可育花药提取物中的降解更为严重；然而，在可育和细胞质雄性不育花药提取物中，底物敏感性顺序——肌球蛋白>磷酸化酶b>牛血清白蛋白和卵清蛋白>β-半乳糖苷酶——是相同的。
