Regulation of photomorphogenesis by expression of mammalian biliverdin reductase in transgenic Arabidopsis plants
Regulation of photomorphogenesis by expression of mammalian biliverdin reductase in transgenic Arabidopsis plants
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DOI：
10.1105/tpc.9.5.675
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发表时间：
1997-05-01
期刊：
影响因子：
11.6
通讯作者：
Lagarias, JC
中科院分区：
文献类型：
--
作者：
Lagarias, DM;Crepeau, MW;Lagarias, JC
光敏色素感光体的光调节活性需要线性四吡咯辅基光敏色素移动素的合成和共价连接。由于哺乳动物酶bitiverdin IX α还原酶（BVR）能够在体外功能性地抑制光敏色素，因此进行这项研究以确定转基因植物中的BVR表达是否会阻止体内功能活性光敏色素的合成。在这里，我们表明，质体为目标，组成型表达的BVR在拟南芥产量的植物，显示异常的光形态建成在其整个生命周期。三个转基因BVR线表现出25倍的BVR表达范围的光生物学和生化分析确定，BVR依赖的表型是紧密依赖的，多效性，并与多种光敏色素活动的损失相一致。BVR表达转基因植物的叶绿素积累是特别敏感的光通量率增加，这是一致的光敏色素在光耐受性的重要作用。在蓝光下，转基因BVR植物表现出伸长的下胚轴，但保留了向光行为和完全脱黄的能力。定向BVR表达可能被证明是有用的探测光敏色素介导的反应的细胞和发育基础，并选择性控制光介导的植物生长和发育的各个方面。
The photoregulatory activity of the phytochrome photoreceptor requires the synthesis and covalent attachment of the linear tetrapyrrole prosthetic group phytochromobilin. Because the mammalian enzyme bitiverdin IX alpha reductase (BVR) is able to functionally inactivate phytochromobilin in vitro, this investigation was undertaken to determine whether BVR expression in transgenic plants would prevent the synthesis of functionally active phytochrome in vivo. Here, we show that plastid-targeted, constitutive expression of BVR in Arabidopsis yields plants that display aberrant photomorphogenesis throughout their life cycle. Photobiological and biochemical analyses of three transgenic BVR lines exhibiting a 25-fold range of BVR expression established that the BVR-dependent phenotypes are tight dependent, pleiotropic, and consonant with the loss of multiple phytochrome activities. Chlorophyll accumulation in BVR-expressing transgenic plants was particularly sensitive to increased light fluence rates, which is consistent with an important role for phytochrome in light tolerance. Under blue light, transgenic BVR plants displayed elongated hypocotyls but retained phototropic behavior and the ability to fully deetiolate. Directed BVR expression may prove to be useful for probing the cellular and developmental basis of phytochrome-mediated responses and for selective control of individual aspects of light-mediated plant growth and development.