HOS1, a genetic locus involved in cold-responsive gene expression in Arabidopsis
HOS1, a genetic locus involved in cold-responsive gene expression in Arabidopsis
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DOI：
10.1105/tpc.10.7.1151
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发表时间：
1998-07-01
期刊：
影响因子：
11.6
通讯作者：
Zhu, JK
中科院分区：
文献类型：
--
作者：
Ishitani, M;Xiong, LM;Zhu, JK
低温胁迫诱导植物中多种基因的表达。然而，在冷胁迫下激活基因表达的信号转导途径知之甚少。低温信号缺陷突变体将有助于植物对低温反应的分子分析，并最终导致冷胁迫受体和细胞内信号组分的鉴定和克隆。在这项研究中，我们描述了一种植物突变体在其响应低温的影响。通过荧光素酶成像鉴定的拟南芥hos 1 -1突变引起冷响应基因的超诱导，例如RD 29 A、COR 47、COR 15 A、KIN 1和ADH。虽然这些基因也诱导脱落酸，高盐，或聚乙二醇除了冷，hos 1 -1突变只增强其表达在冷胁迫下。遗传分析表明hos 1 -1是一个核基因的单隐性突变。我们的研究使用萤火虫荧光素酶报告基因的控制下的冷响应RD 29 A启动子表明，冷响应基因可以诱导的温度高达19摄氏度的hos 1 -1植物。相反，野生型植物在10 ℃或更高温度下不表达荧光素酶报告基因。与野生型相比，hos 1 -1植株的哈代较差，但经过2天的冷驯化，hos 1 -1植株获得了与野生型相同程度的抗冻性。hos 1 -1植物比野生型植物开花更早，并且表现出组成性春化。总而言之，我们的研究结果表明，HOS 1位点是植物细胞冷信号传导的重要负调节因子，并且在控制基因表达方面发挥着关键作用。冷胁迫、抗冻性和开花时间。
Low-temperature stress induces the expression of a variety of genes in plants. However, the signal transduction pathway(s) that activates gene expression under cold stress is poorly understood. Mutants defective in cold signaling should facilitate molecular analysis of plant responses to low temperature and eventually lead to the identification and cloning of a cold stress receptor(s) and intracellular signaling components. In this study, we characterize a plant mutant affected in its response to low temperatures. The Arabidopsis hos1-1 mutation identified by luciferase imaging causes superinduction of cold-responsive genes, such as RD29A, COR47, COR15A, KIN1, and ADH. Although these genes are also induced by abscisic acid, high salt, or polyethylene glycol in addition to cold, the hos1-1 mutation only enhances their expression under cold stress. Genetic analysis revealed that hos1-1 is a single recessive mutation in a nuclear gene. Our studies using the firefly luciferase reporter gene under the control of the cold-responsive RD29A promoter have indicated that cold-responsive genes can be induced by temperatures as high as 19 degrees C in hos1-1 plants. In contrast, wild-type plants do not express the luciferase reporter at 10 degrees C or higher. Compared with the wild type, hos1-1 plants are less cold hardy, Nonetheless, after 2 days of cold acclimation, hos1-1 plants acquired the same degree of freezing tolerance as did the wild type. The hos1-1 plants flowered earlier than did the wild-type plants and appeared constitutively vernalized, Taken together, our findings show that the HOS1 locus is an important negative regulator of cold signal transduction in plant cells and that it plays critical roles in controlling gene expression under cold stress, freezing tolerance, and flowering time.