Heterogeneity of plant mitochondrial responses underpinning respiratory acclimation to the cold in Arabidopsis thaliana leaves
Heterogeneity of plant mitochondrial responses underpinning respiratory acclimation to the cold in Arabidopsis thaliana leaves
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DOI：
10.1111/j.1365-3040.2005.01475.x
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发表时间：
2006-05-01
影响因子：
7.3
通讯作者：
Atkin, OK
中科院分区：
文献类型：
--
作者：
Armstrong, AF;Logan, DC;Atkin, OK
在这项研究中，我们调查是否线粒体丰度，超微结构和活性的变化参与呼吸冷驯化反应的耐寒植物拟南芥叶片。共聚焦显微镜[使用具有靶向线粒体的绿色荧光蛋白（GFP）的植物]和透射电子显微镜（TEM）用于观察线粒体形态、丰度和超微结构的变化。在分离的线粒体和完整的叶片组织的呼吸流量的测量也进行了。对热生长（WG，25/20 ℃白天/晚上）、3周冷处理（CT）和冷发育（CD）的叶进行取样。尽管CT叶表现出一些适应的证据（如在中等测量温度下较高的呼吸速率所证明的），但只有CD叶能够在寒冷中重新建立呼吸通量。与CD叶中呼吸通量的恢复相关的是：（1）表皮细胞中每单位体积组织中线粒体的总体积增加;（2）叶肉细胞线粒体内嵴与基质的比率增加;和（3）从全叶匀浆中分离的线粒体中产生能量的细胞色素途径的能力增加。无论生长温度，我们发现，对比细胞类型表现出明显的差异，线粒体超微结构，形态和丰度。总的来说，我们的数据证明了线粒体反应的多样性和组织特异性，这些反应是呼吸适应寒冷的基础，并揭示了叶片内线粒体结构和丰度的异质性。
In this study, we investigated whether changes in mitochondrial abundance, ultrastructure and activity are involved in the respiratory cold acclimation response in leaves of the cold-hardy plant Arabidopsis thaliana. Confocal microscopy [using plants with green fluorescence protein (GFP) targeted to the mitochondria] and transmission electron microscopy (TEM) were used to visualize changes in mitochondrial morphology, abundance and ultrastructure. Measurements of respiratory flux in isolated mitochondria and intact leaf tissue were also made. Warm-grown (WG, 25/20 degrees C day/night), 3-week cold-treated (CT) and cold-developed (CD) leaves were sampled. Although CT leaves exhibited some evidence of acclimation (as evidenced by higher rates of respiration at moderate measurement temperatures), it was only the CD leaves that were able to re-establish respiratory flux within the cold. Associated with the recovery of respiratory flux in the CD leaves were: (1) an increase in the total volume of mitochondria per unit volume of tissue in epidermal cells; (2) an increase in the ratio of cristae to matrix within mesophyll cell mitochondria; and (3) an increase in the capacity of the energy-producing cytochrome pathway in mitochondria isolated from whole leaf homogenates. Regardless of growth temperature, we found that contrasting cell types exhibited distinct differences in mitochondrial ultrastructure, morphology and abundance. Collectively, our data demonstrated the diversity and tissue-specific nature of mitochondrial responses that underpin respiratory acclimation to the cold, and revealed the heterogeneity of mitochondrial structure and abundance that exists within leaves.