萌发中花生胚轴的耐干性与热稳定蛋白

成熟花生种子吸胀１８ ｈ 发芽率达１００ ％ 。在这１８ ｈ 的范围内，胚轴即使经干燥处理，萌发生长率仍保持１００ ％ ，而热稳定蛋白含量变化很小。吸胀２４ ｈ 后，经干燥的花生胚完全丧失萌发生长能力。ＳＤＳＰＡＧＥ和双向电泳表明，花生胚轴的热稳定蛋白主要是贮藏蛋白，该蛋白中的花生球蛋白大亚基，伴花生球蛋白Ｉ和２Ｓ 蛋白的降解与胚轴的耐干性丧失有关。

Heat stable Proteins and Desiccation Tolerance in Axes of Germinating Peanut Seeds

Peanut (Arachis hypogaea L.) seed reached 100% germination at 18 h after imbibition (Fig.1). Peanut axes from seeds undergoing for less than 18 h and subjected to desiccation maintained 100% germinability, but those from seeds imbibing for 24 h had zero germinability (Fig.2). During germination, the content of heat stable proteins in axes lowered slowly. After 24 h imbibition, the content of heat stable proteins in axes declined remarkably (Table 1). SDS PAGE and two dimensional electrophoresis showed that the heat stable proteins in peanut axes consisted mainly of storage proteins. The degradation of the major subunits of arachin, conarachin I and 2S proteins were related to the loss of desiccation tolerance in germinated peanut axes (Figs.3,4).