图1 黄皮种子脱水过程中含水量(A)和存活率(B)的变化(平均值±标准误差, n = 25)。种子在25-28 ℃和72%-80%相对湿度中分别脱水0、4、7和10天, 然后测定胚轴、子叶和种子的含水量, 以及胚轴和种子的存活率。种子的含水量与子叶的含水量相同。整粒种子和离体胚轴在30 ℃和黑暗下萌发10天。

Fig. 1 Changes in water content (A) and survival (B) during dehydration of Clausena lansium seeds (mean ± SE, n = 25). Seeds were dehydrated at 25-28 °C and 72%-80% relative humidity for 0, 4, 7 and 10 days, respectively, and then water content of axes, cotyledons and seeds and survival of axes and seeds were immediately measured. The water content of cotyledons and seeds is the same. Whole seed and excised axis were incubated at 30 °C and in darkness.

图2 黄皮胚轴和子叶的呼吸速率对脱水的反应。未脱水和脱水的种子在30 ℃和黑暗条件下蒸馏水中吸胀24 h, 然后在25 ℃下分别测定离体胚轴和粉碎子叶的呼吸速率。所有的数据是10个胚轴或者1 g粉碎子叶3次重复的平均值±标准误差。相同的大写和小写字母分别代表胚轴和子叶各处理间无显著性差异(S-N-K, p = 0.05)。

Fig. 2 Response of respiratory rate of Clausena lansium embryo axis and cotyledon to dehydration. The un-dehydrated and dehydrated seeds were imbibed in distilled water at 30 °C in darkness for 24 h, and then respiratory rate of excised embryo axes and grinded cotyledons were measured at 25 °C. All values are mean ± SE of three replicates of 10 axes or 1 g grinded cotyledons. Same uppercase and lowercase letters indicate no significant difference between treatments in embryo axes and cotyledons, respectively (S-N-K, p = 0.05).

图3 脱水对黄皮胚轴和子叶线粒体细胞色素c氧化酶(CCO)活性(A)和外膜完整性(B)的影响。未脱水和脱水的种子在30 ℃和黑暗条件下吸胀24 h, 然后分别提取胚轴和子叶的线粒体, 并测定CCO活性和计算CCO活性的潜伏期(线粒体外膜的完整性)。所有的数据是200个胚轴或者100 g子叶3次重复的平均值±标准误差。相同的大写和小写字母分别代表胚轴和子叶各处理间无显著性差异 (S-N-K, p = 0.05)。

Fig. 3 Effect of dehydration on cytochrome c oxidase (CCO) activity of mitochondria (A) and integrity of outer mitochondrial membrane (B) in Clausena lansium embryo axis and cotyledon. The un-dehydrated and dehydrated seeds were imbibed in distilled at 30 °C in darkness for 24 h, and the mitochondria of embryo axes and cotyledons were then extracted, respectively. The CCO activity of mitochondria was assayed, and the latency of the CCO activity was calculated to estimate the integrity of outer mitochondrial membrane. All values are mean ± SE of three replicates of 200 axes or 100 g cotyledons. Same uppercase and lowercase letters indicate no significant difference between treatments in embryo axes and cotyledons, respectively (S-N-K, p = 0.05).

图4 黄皮种子脱水过程中胚轴和子叶线粒体细胞色素c氧化酶途径(A)和交替氧化酶途径(B)呼吸速率的变化。所有的数据是200个胚轴或者100 g子叶3次重复的平均值±标准误差。相同的大写和小写字母分别代表胚轴和子叶各处理间无显著性差异 (S-N-K, p = 0.05)。

Fig. 4 Changes in respiratory rate of cytochrome c oxidase pathway (A) and alternative oxidase pathway (B) in mitochondria of embryo axis and cotyledon during dehydration of Clausena lansium seeds. All values are mean ± SE of three replicates of 200 axes or 100 g cotyledons. Same uppercase and lowercase letters indicate no significant difference between treatments in embryo axes and cotyledons, respectively (S-N-K, p = 0.05)

图5 黄皮种子脱水过程中胚轴和子叶线粒体活性氧(ROS)清除酶活性的变化。A, 超氧化物岐化酶(SOD)。B, 抗坏血酸过氧化酶(APX)。C, 脱氢抗坏血酸还原酶(DHAR)。D, 谷胱甘肽还原酶(GR)。所有的数据是200个胚轴或者100 g子叶3次重复的平均值±标准误差。相同的大写和小写字母分别代表胚轴和子叶各处理间无显著性差异(S-N-K, p = 0.05)。

Fig. 5 Changes in activities of reactive oxygen species (ROS) scavenging enzymes in mitochondria of embryo axis and cotyledon during dehydration of Clausena lansium seeds. A, superoxide dismutase (SOD). B, ascorbate peroxidase (APX). C, dehydroascorbate reductase (DHAR). D, glutathione reductase (GR). All values are mean ± SE of three replicates of 200 axes or 100 g cotyledons. Same uppercase and lowercase letters indicate no significant difference between treatments in embryo axes and cotyledons, respectively (S-N-K, p = 0.05).