Histone modification analysis in root tips of Non-heading Chinese cabbage under Salt Stress

Non-heading Chinese cabbage (NHCC, Brassica campestris (syn. Brassica rapa) ssp. chinensis) is a Brassicais, a plant of Cruciferae, and it is one of the important leafy vegetables in China. With the increasingly serious soil salinization, salt stress limits the growth and development of NHCC, and reduces its yield and quality. Histone modification plays an important role in plant response to salt stress by regulating the expression of key genes. However, the mechanism of histone modification in root tips of NHCC in response to salt stress is still unclear. Therefore, the construction of apical histone modification regulatory network of NHCC is of great significance to analyze the molecular mechanism of its apical response to salt stress. In this study, the dynamic changes of H3K27Ac and H3K27Me3 histone modifications in the short-term response of NHCC root tips to salt stress were explored by using CUT&Tag-seq and RNA-seq. H3K27Ac and H3K27Me3 respond rapidly and continuously to salt stress, and respond to salt stress by regulating cell wall structural components, trehalose metabolism, and transferase activity. Therefore, the cell wall component may be an important cell structure in response to salt stress in root tip of NHCC. In addition, we used virus-induced gene silencing (VIGS) to preliminarily verify that H3K27Ac positively regulated the salt tolerance of NHCC by activating the transcription of PMEI4 (pectin methylesterase inhibitor 4). In summary, this study constructed a transcriptional regulatory network in which histone participates in root tip response of NHCC under salt stress.