Blue Light-Triggered Chemical Reactions Underlie Phosphate Deficiency-Induced Inhibition of Root Elongation of Arabidopsis Seedlings Grown in Petri Dishes
Blue Light-Triggered Chemical Reactions Underlie Phosphate Deficiency-Induced Inhibition of Root Elongation of Arabidopsis Seedlings Grown in Petri Dishes
复制标题
蓝光引发的化学反应是磷酸盐缺乏引起的培养皿中拟南芥幼苗根伸长抑制的基础
DOI：
10.1016/j.molp.2019.08.001
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发表时间：
2019-11-04
期刊：
影响因子：
27.5
通讯作者：
Liu, Dong
中科院分区：
文献类型：
--
作者：
Zheng, Zai;Wang, Zhen;Liu, Dong
为了耐受环境中的磷酸盐（Pi）缺乏，植物改变了它们的发育和代谢程序。在过去的二十年里，研究人员广泛使用培养皿培养的模式植物拟南芥幼苗来研究根发育对Pi缺乏反应的分子机制。培养皿中生长的拟南芥幼苗对缺磷的一个典型的发育反应是主根生长受到抑制。这种反应通常被认为是增强侧根和根毛的产生，这增加了植物获得Pi的能力，因此被认为是一种活跃的细胞反应。在这里，我们报告说，直接照射根表面的蓝光是至关重要的，足够的磷缺乏诱导的抑制拟南芥幼苗PR生长。我们进一步表明，蓝光引发的苹果酸介导的光芬顿反应和典型的芬顿反应在根质外体中形成Fe氧化还原循环。这种Fe氧化还原循环导致产生抑制PR生长的羟基自由基。除了揭示PI缺乏诱导的PR生长抑制的分子机制外，我们的工作还表明这种发育变化不是一种积极的细胞反应;相反，它是透明培养皿中根生长引起的表型。这一发现是重要的，因为照明，透明的培养皿已被常规用于研究拟南芥根对环境变化的反应。
To tolerate phosphate (Pi) deficiency in the environment, plants alter their developmental and metabolic programs. In the past two decades, researchers have extensively used Petri dish-grown seedlings of the model plant Arabidopsis thaliana to study the molecular mechanisms underlying root developmental responses to Pi deficiency. A typical developmental response of the Petri dish-grown Arabidopsis seedlings to Pi deficiency is the inhibited growth of primary root (PR). This response is generally thought to enhance the production of lateral roots and root hairs, which increases the plant's ability to obtain Pi and is therefore regarded as an active cellular response. Here, we report that direct illumination of root surface with blue light is critical and sufficient for Pi deficiency-induced inhibition of PR growth in Arabidopsis seedlings. We further show that a blue light-triggered malate-mediated photo-Fenton reaction and a canonical Fenton reaction form an Fe redox cycle in the root apoplast. This Fe redox cycle results in the production of hydroxyl radicals that inhibit PR growth. In addition to revealing the molecular mechanism underlying Pi deficiency-induced inhibition of PR growth, our work demonstrated that this developmental change is not an active cellular response; instead, it is a phenotype resulting from root growth in transparent Petri dishes. This finding is significant because illuminated, transparent Petri dishes have been routinely used to study Arabidopsis root responses to environmental changes.