[原生質絲] 生理時鐘調控的細胞溝通 20191116 Plant Physiology

Plant cell-cell transport via plasmodesmata is regulated by light and the circadian clock

Jacob O. Brunkard and Patricia Zambryski

ABSTRACT

Plasmodesmata (PD) are essential for plant development, but little is known about their regulation. Several studies have linked PD transport to chloroplast-centered signaling networks, but the physiological significance of this connection remains unclear. Here, we show that PD transport is strongly regulated by light and the circadian clock. Light promotes PD transport during the day, but light is not sufficient to increase rates of PD transport at night, suggesting a circadian gating mechanism. Silencing expression of the core circadian clock gene, LHY/CCA1, allows light to strongly promote PD transport during subjective night, confirming that the canonical plant circadian clock controls the PD transport light response. We conclude that PD transport is dynamically regulated during the day/night cycle. Due to the many roles of PD in plant biology, this discovery has strong implications for plant development, physiology, and pathogenesis.

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植物原生質絲的運輸會受到生理時鐘以及光的調控

摘要

原生質絲對於植物的生長來說是必要的，但是對於原生質絲的調控，我們一直知道的都很少。許多研究將原生質絲的運輸和以葉綠體為中鄉的訊息傳導連結再一起，但是這個調控的連結在生理上的意義，我們仍然不是很清楚。在此，我們報導了原生質絲的運輸，會被生理時鐘所調控。光可以在日間促進原生質絲的運輸，但是在夜晚，單純的光照並沒有辦法增加原生質絲運輸的效率，顯示除了光照外，生理時鐘在背後調控了這個運輸的機制。當我們將生理時鐘網路內，主要的基因LHY/CCA1表現量減低後發現，光在接下來的“夜晚”就可以促進原生質絲的運輸，顯示了生理時鐘可以影響原生質絲在受到光調控與否。我們總結，原生質絲會受到日夜循環的動態調節。由於原生質絲在植物生理上扮演了許多的角色，我們的發現對於植物的生長、生理以及病理學上蘊含了非常多的意義。

原文出處 http://www.plantphysiol.org/content/early/2019/10/10/pp.19.00460

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＊原生質絲的運輸，對於很多植物的生長發育以及做為病原菌的入侵的通道，深深地影響了植物。但是這個調控機制，到目前為止，我們知道的很多都關於原生質絲參與了哪些生長發育、免疫相關的資訊。真正調控的機制，知道得非常有限。之前這一個實驗室曾經做了一系列的突變植物篩選，找到了四個在胚胎發育時期，因為原生質絲調控出問題，而提早停止生長的基因。而這些基因都與葉綠體或粒線體有關。這篇文章又再讓原生質絲與光照、生理時鐘連上了關係，似乎在暗示了葉綠體可能在這其中扮演了溝通的角色。那葉綠體、生理時鐘、光照，最後會怎麼樣連結再一起呢？ 已經知道一些胞器與細胞和溝通的機制，不知是否這些機制受損的突變植株，原生質絲的調控是否也有所改變？ 未來還蠻值得繼續追蹤下去的！