The development of microbodies (glyoxysomes and leaf peroxisomes) in cotyledons of germinating watermelon seedlings.
The development of microbodies (glyoxysomes and leaf peroxisomes) in cotyledons of germinating watermelon seedlings.
复制标题
发芽西瓜幼苗子叶中微体（乙醛酸酶体和叶过氧化物酶体）的发育。
DOI：
10.1104/pp.55.2.258
复制
发表时间：
1975
期刊：
影响因子：
7.4
通讯作者：
H. Beevers
中科院分区：
文献类型：
--
作者：
Takeshi Kagawa;H. Beevers
乙醛酸酶体和叶过氧化物酶体的个体发育已在发芽西瓜（Citrullus vulgaris）幼苗的子叶中进行了检查。通过刀片匀浆提取子叶的细胞器，并通过蔗糖密度梯度分级分离微体。两种微体在蔗糖梯度上具有相同的平均平衡密度。在转光4天和10至12天的幼苗中检查叶过氧化物酶体的发育。在黑暗中保存至 10 至 12 天的幼苗中，乙醛酸酶几乎消失，并且这种损失与微生物蛋白的相应损失同时发生。在此期间，过氧化物酶体活性较低且仅发生轻微变化。在这个阶段转移到光下，过氧化物酶体酶的活性显着升高。残留的乙氧化酶体活性完全消失，微体过氧化氢酶和微体蛋白的发育模式与光诱导的乙氧化酶体消失平行。当4日龄的黑暗生长的具有最大乙氧化酶体活性的幼苗暴露于光时，观察到类似的微体发育模式。过氧化物酶体酶的活性增加，乙醛酸酶体的消失速度比黑暗中更快。这些变化再次与微体过氧化氢酶和微体蛋白的加速消亡同时发生。因此，在这两种条件下，乙醛酸体在过氧化物酶体发育过程中被选择性破坏，并且产生的过氧化物酶体的量不足以抵消乙醛酸体蛋白的损失。结果不支持乙醛酸酶体在葫芦子叶发育过程中转化为叶过氧化物酶体的论点，而支持两种微体彼此独立产生的观点。
The ontogeny of glyoxysomes and leaf peroxisomes has been examined in the cotyledons of germinating watermelon (Citrullus vulgaris) seedlings. Organelles from the cotyledons were extracted by razor blade homogenization and microbodies were separated by sucrose density gradient fractionation. Both kinds of microbodies have the same mean equilibrium density on sucrose gradients.The development of leaf peroxisomes was examined in seedlings transferred to light at 4 days and 10 to 12 days. In seedlings maintained in darkness to the age of 10 to 12 days, glyoxysomal enzymes virtually disappeared, and the losses were paralleled by a corresponding loss in microbody protein. During this period peroxisomal activity was low and changed only slightly. On transfer to light at this stage, the activity of peroxisomal enzymes rose strikingly. The residual glyoxysomal activity disappeared completely, and the developmental pattern of microbody catalase and microbody protein paralleled the light-induced glyoxysomal disappearance.Similar patterns of microbody development were observed when 4-day-old dark-grown seedlings with maximum glyoxysomal activities were exposed to light. The activity of the peroxisomal enzymes increased and the glyoxysomal enzymes disappeared at a faster rate than in darkness. These changes were again paralleled by the accelerated demise of microbody catalase and microbody protein. Thus under both conditions glyoxysomes were selectively destroyed during peroxisomal development, and the amount of peroxisomes produced was insufficient to offset the loss of glyoxysomal protein. The results do not support the contention that glyoxysomes are transformed to leaf peroxisomes in developing cucurbit cotyledons and favor the view that the two kinds of microbody arise independently of each other.