Key Message

Short-term exposure to high temperatures modulates the aromatic cytokinin profile of radiata pine embryonal masses when measured 8 weeks after initiation.

Abstract Recent research has demonstrated that cytokinins could be involved in abiotic stress responses. However, little research has been published about the role of endogenous aromatic cytokinins during these processes. Therefore, in this study, different temperature and incubation periods (23 ºC, 8 weeks; 40 ºC, 4 h; 50 ºC, 30 min; 60 ºC, 5 min) were applied during induction of radiata pine somatic embryogenesis and the aromatic cytokinin content of the resulting embryonal masses was measured. Results indicated that temperature during induction had a significant effect on the profile of most of the aromatic cytokinins detected. All tested higher temperatures than control provoked a decline in some free bases, including N⁶-benzyladenine, ortho-Topolin and para-Topolin. On the other hand, the values of N⁶-benzyladenine nucleotides, ribosides and irreversible metabolites (9G), as well as para-Topolin ribosides, increased in embryonal masses originating from 40 ºC treatment. These results suggest that despite not being traditionally considered part of the stress response machinery, aromatic cytokinins might be involved in heat-stress responses during early stages of somatic embryogenesis in radiata pine.

中文翻译：

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体细胞胚发生过程中施加热应激后辐射松辐射体中内源性芳香细胞分裂素的定量

关键信息

在启动后8周进行测量时，短期暴露于高温会调节辐射松松果的芳香细胞分裂素分布。

摘要最近的研究表明，细胞分裂素可能参与非生物胁迫反应。然而，关于内源性芳香细胞分裂素在这些过程中的作用的研究很少。因此，在这项研究中，在辐射松树体细胞胚发生和芳香族细胞分裂素含量的诱导过程中，采用了不同的温度和潜伏期（23ºC，8周； 40ºC，4 h； 50ºC，30 min； 60ºC，5 min）。测量得到的胚胎质量的百分数。结果表明诱导过程中的温度对检测到的大多数芳香族细胞分裂素的分布有显着影响。与对照相比，所有测试的较高温度都引起某些游离碱的下降，包括N ^6-苄腺嘌呤，邻-Topolin和对-Topolin。另一方面，源自40ºC处理的胚胎质量中N ^6-苄腺嘌呤核苷酸，核糖苷和不可逆代谢物（9G）以及对-Topolin核糖苷的值均增加。这些结果表明，尽管传统上不将其视为应激反应机制的一部分，但芳香族细胞分裂素可能在辐射松体细胞胚发生的早期阶段参与了热应激反应。