Physiological aspects and experimental reversion of flowering in Fargesia murieliae (Poaceae, Bambusoideae)
Physiological aspects and experimental reversion of flowering in Fargesia murieliae (Poaceae, Bambusoideae)
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DOI：
10.2307/3668597
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发表时间：
1999-01-01
期刊：
影响因子：
--
通讯作者：
Debergh, P.
中科院分区：
文献类型：
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作者：
Gielis, J.;Goetghebeur, P.;Debergh, P.
大约从1993年到现在（1998年），数以百万计的箭竹（一种观赏竹）在西欧单果开花。所有植物都是单一基因的分株，大约80年前引入欧洲，所有这些分株的同时开花构成了一个巨大的复合花序。开花植物在不同的光强度和温度条件下产生不同的开花发育模式。在低光照强度和高环境温度（22-25℃）下，最终通过开花秆的基芽发育营养芽来观察开花的逆转。在诱导氧化应激的条件下（充足的阳光和干旱），开花和衰老会迅速进行。衰老过程与氧化应激有关，氧化应激通过半花序中超氧化物歧化酶和抗坏血酸过氧化物酶的活性升高来测量。通过过氧化氢酶活性的强光还原，高光强度直接导致细胞主要防御机制之一失活，从而有效加速开花和衰老。在包围半花序（短枝旁区）的佛焰苞叶片中，观察到 DNA 复制以及 DNA 从细胞核中丢失。由于这种现象是在末端花序发育之前的绿色佛焰苞中观察到的，因此 DNA 复制是衰老的一个非常早期的标志。衰老前额外的 DNA 合成在细胞分裂素生物合成中发挥着重要作用。
From about 1993 to the present (1998), millions of plants of Fargesia murieliae, an ornamental bamboo, were flowering monocarpically in western Europe. All plants being ramets of a single genet, introduced in Europe about 80 years ago, the simultaneous flowering of all these ramets constitutes a single giant compound inflorescence. Flowering plants were subjected to different conditions of light intensity and temperature yielding different modes of development of flowering. Under low light intensity and high ambient temperatures (22-25degreeC), reversion of flowering is ultimately observed by development of vegetative shoots from basal buds of flowering culms. Under conditions that induce oxidative stress (full sun and drought) flowering and senescence proceed rapidly. The process of senescence is linked to oxidative stress as measured in elevated activities of superoxide dismutase and ascorbate peroxidase in the semelauctant inflorescences. By strong photoreduction of catalase activity, high light intensity is directly responsible for inactivation of one of the major defence mechanisms of the cells, thereby effectively accelerating flowering and senescence. In blades of spathes subtending the semelauctant inflorescences (short paracladial zone), DNA replication as well as loss of DNA from nuclei is observed. As this phenomenon is observed in green spathes prior to the development of the terminal inflorescence, DNA replication is a very early marker for senescence. A role for extra DNA synthesis prior to senescence is suggested in cytokinin biosynthesis.