The Phycomyces madA gene encodes a blue-light photoreceptor for phototropism and other light responses
The Phycomyces madA gene encodes a blue-light photoreceptor for phototropism and other light responses
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DOI：
10.1073/pnas.0600633103
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发表时间：
2006-03-21
影响因子：
11.1
通讯作者：
Heitman, J
中科院分区：
文献类型：
--
作者：
Idnurm, A;Rodríguez-Romero, J;Heitman, J
Blakesleeanus是一种丝状真菌，产生突出的细长单细胞，延伸到空气中长达10厘米，每个这样的孢子囊支撑着一个含有孢子的球体用于传播。这种生物体已经成为检测光、化学物质、触摸、风、重力和邻近物体等各种环境信号的模型。特别是，孢子囊体的生长受光的调节，它表现出向光性，通过弯曲向近紫外和蓝色波长和远离远紫外波长的方式，在生理上类似于植物向光性反应。PhycombromadA突变体在40多年前首次被分离出来，它们表现出对光的敏感性降低。在这里，我们确定了两个（重复）同源物的白色衣领1家庭的蓝光光感受器在Phycometra。我们描述的madA突变株包含在这些基因之一的点突变，这些突变cosegregate与缺陷的向光性遗传杂交后。因此，向光性反应的真菌通过madA和植物通过phototropin依赖于不同的蛋白质，然而，这些蛋白质共享一个保守的黄素结合域的光子检测。
Phycomyces blakesleeanus is a filamentous zygomycete fungus that produces striking elongated single cells that extend up to 10 cm into the air, with each such sporangiophore supporting a sphere containing the spores for dispersal. This organism has served as a model for the detection of environmental signals as diverse as light, chemicals, touch, wind, gravity, and adjacent objects. In particular, sporangiophore growth is regulated by light, and it exhibits phototropism by bending toward near-UV and blue wavelengths and away from far-UV wavelengths in a manner that is physiologically similar to plant phototropic responses. The Phycomyces madA mutants were first isolated more than 40 years ago, and they exhibit reduced sensitivity to light. Here, we identify two (duplicated) homologs in the White Collar 1 family of blue-light photoreceptors in Phycomyces. We describe that the madA mutant strains contain point mutations in one of these genes and that these mutations cosegregate with a defect in phototropism after genetic crosses. Thus, the phototropic responses of fungi through madA and plants through phototropin rely on diverse proteins; however, these proteins share a conserved flavin-binding domain for photon detection.