Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Genomics. 2020 Nov;112(6):5282-5294. doi: 10.1016/j.ygeno.2020.09.052. Epub 2020 Sep 26.
Nitrogen fixation in legumes requires the development of specialized organs called root nodules. Here we characterized the high-confidence transcriptome and genome-wide patterns of H3K4me3 marks in soybean roots and mature nodules symbiotic with Sinorhizobium fredii. Changes in H3K4me3 levels were positively associated with the transcription levels of functional genes in the nodules. The up-regulation of H3K4me3 levels was not only present in leghaemoglobin and nodulin-related genes, but also in genes involved in nitrogen and carbon metabolic pathways. In addition, genes regulating the transmembrane transport of metal ions, phosphates, sulphates, peptides, and sugars were differentially modified. On the contrary, a loss of H3K4me3 marks was found in several key transcription factor genes and was correlated with the down-regulation of the defense-related network in nodules, which could contribute to nodule maintenance. All these findings demonstrate massive reprogramming of gene expressions via alterations in H3K4me3 levels in the genes in mature soybean nodules.
豆科植物的固氮作用需要发育专门的器官，称为根瘤。在这里，我们对大豆根和与中华根瘤菌共生的成熟根瘤中的高可信度转录组和 H3K4me3 标记的全基因组模式进行了描述。H3K4me3 水平的变化与根瘤中功能基因的转录水平呈正相关。H3K4me3 水平的上调不仅存在于豆血红蛋白和类结节素相关基因中，而且存在于参与氮和碳代谢途径的基因中。此外，调节金属离子、磷酸盐、硫酸盐、肽和糖的跨膜转运的基因也发生了差异修饰。相反，在几个关键的转录因子基因中发现了 H3K4me3 标记的丧失，与根瘤中防御相关网络的下调相关，这可能有助于根瘤的维持。所有这些发现表明，在成熟大豆根瘤中的基因中，通过 H3K4me3 水平的改变，大量基因表达发生了重编程。
