Chemical induction of rapid and reversible plastid filamentation in Arabidopsis thaliana roots
Chemical induction of rapid and reversible plastid filamentation in Arabidopsis thaliana roots
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DOI：
10.1111/j.1399-3054.2010.01352.x
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发表时间：
2010-06-01
影响因子：
6.4
通讯作者：
Fujiwara, Makoto T.
中科院分区：
文献类型：
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作者：
Itoh, Ryuuichi D.;Yamasaki, Hideo;Fujiwara, Makoto T.
质体根据其发育状态呈现不同的形态，但发育调控质体形态发生的基础尚不清楚。化学诱导质体形态的改变将是研究这一问题的有用工具；然而，目前还没有发现这种化学物质。在这里，我们发现抗霉素A是一种有效的呼吸抑制剂，可以快速和可逆地改变拟南芥质体的形态。在根皮质、下胚轴、子叶表皮和真叶表皮中，抗霉素处理和未处理组织的线粒体形态无显著差异。相反，抗霉素引起主根成熟皮质质体的极端丝化。这种现象在成熟的根皮层中特别观察到。其他线粒体呼吸抑制剂（鱼tenone和羰基氰化物间氯苯腙）、过氧化氢、s -亚硝基-n -乙酰青霉胺[一氧化氮（NO）供体]和3-（3,4-二氯苯基）-1,1-二甲基脲在本研究条件下没有模拟这种现象。抗霉素诱导的质体成丝在化学处理开始后5分钟内开始，并在1小时内完成。抗霉素冲洗后质体形态在7小时内恢复，表明成丝是可逆的。抗霉素和细胞骨架抑制剂（去美可林或拉曲库林B）或蛋白质合成抑制剂（环己亚胺或氯霉素）的共同应用仍然引起质体丝化。抗霉素A对叶绿体分裂突变体atftsZ1-1和atminE1的质体丝化也有效。水杨酸，一种替代氧化酶抑制剂，被发现唯一抑制丝化，这意味着这种现象可能部分是由线粒体中抗霉素激活的替代氧化酶介导的。
Plastids assume various morphologies depending on their developmental status, but the basis for developmentally regulated plastid morphogenesis is poorly understood. Chemical induction of alterations in plastid morphology would be a useful tool for studying this; however, no such chemicals have been identified. Here, we show that antimycin A, an effective respiratory inhibitor, can change plastid morphology rapidly and reversibly in Arabidopsis thaliana. In the root cortex, hypocotyls, cotyledon epidermis and true leaf epidermis, significant differences in mitochondrial morphology were not observed between antimycin-treated and untreated tissues. In contrast, antimycin caused extreme filamentation of plastids in the mature cortices of main roots. This phenomenon was specifically observed in the mature root cortex. Other mitochondrial respiratory inhibitors (rotenone and carbonyl cyanide m-chlorophenylhydrazone), hydrogen peroxide, S-nitroso-N-acetylpenicillamine [a nitric oxide (NO) donor] and 3-(3,4-dichlorophenyl)-1,1-dimethylurea did not mimic the phenomenon under the present study conditions. Antimycin-induced plastid filamentation was initiated within 5 min after the onset of chemical treatment and appeared to complete within 1 h. Plastid morphology was restored within 7 h after the washout of antimycin, suggesting that the filamentation was reversible. Co-applications of antimycin and cytoskeletal inhibitors (demecolcine or latrunculin B) or protein synthesis inhibitors (cycloheximide or chloramphenicol) still caused plastid filamentation. Antimycin A was also effective for plastid filamentation in the chloroplast division mutants atftsZ1-1 and atminE1. Salicylhydroxamic acid, an alternative oxidase inhibitor, was solely found to suppress the filamentation, implying the possibility that this phenomenon was partly mediated by an antimycin-activated alternative oxidase in the mitochondria.