Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstr 2, 76128 Karlsruhe, Germany.
Protoplasma. 2012 Jun;249 Suppl 2:S137-45. doi: 10.1007/s00709-012-0409-3. Epub 2012 May 9.
Jasmonates (JAs) are plant hormones which are crucial for the response of plants to several biotic and abiotic stresses. Beside this important function, they are involved in several developmental processes throughout plant life. In this short review, we would like to summarize the recent findings about the function of JAs in photomorphogenesis with a main focus on the model plant rice. Early plant development is determined to a large extent by light. Depending on whether seedlings are raised in darkness or in light, they show a completely different appearance which led to the terms skoto- and photomorphogenesis, respectively. The different appearance depending on the light conditions has been used to screen for mutants in photoperception and signalling. By this approach, mutants for several photoreceptors and in the downstream signalling pathways could be isolated. In rice, we and others isolated mutants with a very intriguing phenotype. The mutated genes have been cloned by map-based cloning, and all of them encode for JA biosynthesis genes. The most bioactive form of JAs identified so far is the amino acid conjugate jasmonoyl-isoleucin (JA-Ile). In order to conjugate JA to Ile, an enzyme of the GH3 family, JASMONATE RESISTANT 1, is required. We characterized mutants of OsJAR1 on a physiological and biochemical level and found evidence for redundantly active enzymes in rice.
茉莉酸（JAs）是植物激素，对于植物对多种生物和非生物胁迫的反应至关重要。除了这一重要功能外，它们还参与植物生命过程中的几个发育过程。在这篇简短的综述中，我们将主要以模式植物水稻为例，总结 JAs 在光形态发生中的功能的最新发现。早期植物发育在很大程度上取决于光。根据幼苗是在黑暗中还是在光下生长，它们会呈现出完全不同的外观，这分别导致了“skoto-”和“photomorphogenesis”这两个术语的产生。根据光照条件的不同外观，已经用于筛选光感知和信号转导的突变体。通过这种方法，可以分离出几种光受体和下游信号通路的突变体。在水稻中，我们和其他人分离出了具有非常有趣表型的突变体。通过基于图谱的克隆方法克隆了突变基因，所有这些基因都编码 JA 生物合成基因。到目前为止，鉴定出的最具生物活性的 JAs 形式是氨基酸共轭茉莉酸-异亮氨酸（JA-Ile）。为了将 JA 共轭到 Ile 上，需要一种 GH3 家族的酶，即茉莉酸抗性 1（JAR1）。我们在生理和生化水平上对 OsJAR1 的突变体进行了表征，并在水稻中找到了冗余活性酶的证据。
