Berrocal-Tito G, Sametz-Baron L, Eichenberg K, Horwitz B A, Herrera-Estrella A
Department of Plant Genetic Engineering, Centro de Investigacion y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Irapuato, Apartado Posta 629, Irapuato, Guanajuato 36500, México.
J Biol Chem. 1999 May 14;274(20):14288-94. doi: 10.1074/jbc.274.20.14288.
Photolyases and blue light receptors belong to a superfamily of flavoproteins that make use of blue and UVA light either to catalyze DNA repair or to control development. We have isolated a DNA photolyase gene (phr1) from Trichoderma harzianum, a common soil fungus that is of interest as a biocontrol agent against soil-borne plant pathogens and as a model for the study of light-dependent development. The sequence of phr1 is similar to other Class I Type I eukaryotic photolyase genes. Low fluences of blue light rapidly induced phr1 expression both in vegetative mycelia, which lack photoprotective pigments, and, to a greater extent, in conidiophores. Thus, visible light induces the development of pigmented, resistant spores as well as the expression of phr1, perhaps announcing in this way the imminent exposure to the more damaging short wavelengths of sunlight. Light induction of phr1 in non-sporulating mutants shows that a complete sporulation pathway is not required for photoregulation. The light requirements for photoinduction of phr1 were not altered in dimY photoperception mutants. This suggests that photoinduction of sporulation and of photolyase expression is distinct in their photoreceptor system or in the transduction of the blue light signal.
光解酶和蓝光受体属于黄素蛋白超家族，它们利用蓝光和紫外线A光来催化DNA修复或控制发育。我们从哈茨木霉中分离出一个DNA光解酶基因（phr1），哈茨木霉是一种常见的土壤真菌，作为一种防治土壤传播植物病原体的生物防治剂以及作为研究光依赖性发育的模型而备受关注。phr1的序列与其他I类I型真核光解酶基因相似。低通量蓝光能快速诱导phr1在缺乏光保护色素的营养菌丝体中表达，在分生孢子梗中诱导程度更大。因此，可见光诱导有色素的抗性孢子的发育以及phr1的表达，也许以此方式预示即将暴露于更具破坏性的短波长阳光中。在不产孢突变体中phr1的光诱导表明，光调节不需要完整的产孢途径。在dimY光感知突变体中，phr1光诱导的光需求没有改变。这表明产孢的光诱导和光解酶表达在其光受体系统或蓝光信号转导中是不同的。
