Plant Gene Research Center, National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2009 Sep 30;4(9):e7209. doi: 10.1371/journal.pone.0007209.
Soybean [Glycine max (L.) Merr.] is one of the most important crops for oil and protein resource. Improvement of stress tolerance will be beneficial for soybean seed production.
Six GmPHD genes encoding Alfin1-type PHD finger protein were identified and their expressions differentially responded to drought, salt, cold and ABA treatments. The six GmPHDs were nuclear proteins and showed ability to bind the cis-element "GTGGAG". The N-terminal domain of GmPHD played a major role in DNA binding. Using a protoplast assay system, we find that GmPHD1 to GmPHD5 had transcriptional suppression activity whereas GmPHD6 did not have. In yeast assay, the GmPHD6 can form homodimer and heterodimer with the other GmPHDs except GmPHD2. The N-terminal plus the variable regions but not the PHD-finger is required for the dimerization. Transgenic Arabidopsis plants overexpressing the GmPHD2 showed salt tolerance when compared with the wild type plants. This tolerance was likely achieved by diminishing the oxidative stress through regulation of downstream genes.
These results provide important clues for soybean stress tolerance through manipulation of PHD-type transcription regulator.
大豆（Glycine max (L.) Merr.）是最重要的油料和蛋白质作物之一。提高抗逆性将有利于大豆种子的生产。
鉴定了六个编码 Alfin1 型 PHD 手指蛋白的 GmPHD 基因，它们的表达对干旱、盐、冷和 ABA 处理有不同的反应。这六个 GmPHDs 是核蛋白，能够结合顺式元件“GTGGAG”。GmPHD 的 N 端结构域在 DNA 结合中起主要作用。利用原生质体测定系统，我们发现 GmPHD1 至 GmPHD5 具有转录抑制活性，而 GmPHD6 则没有。在酵母测定中，GmPHD6 可以与除 GmPHD2 之外的其他 GmPHD 形成同源二聚体和异源二聚体。二聚化需要 N 端加可变区，但不需要 PHD 指。过表达 GmPHD2 的转基因拟南芥植物与野生型植物相比表现出耐盐性。这种耐受性可能是通过调节下游基因来减少氧化应激而实现的。
这些结果通过操纵 PHD 型转录调节剂为大豆的抗逆性提供了重要线索。
