Histone acetylation modification affects cell wall degradation and aerenchyma formation in wheat seminal roots under waterlogging

Abstract

Recent studies have shown that histone acetylation, which is an important epigenetic modification, plays a key role in abiotic stress responses in plants. Programmed cell death and aerenchyma formation occur in cortical cells of wheat seminal roots under waterlogging stress. To explore the role of histone acetylation in aerenchyma formation of cortical cells under waterlogging, the seminal roots of two wheat cultivars, namely, Huamai 8 (waterlogging-tolerant) and Huamai 9 (waterlogging-sensitive) were investigated with waterlogging and simultaneous treatment with an acetylation inhibitor. In this study, the immunefluorescence technique and Western blotting were used to determine the histone acetylation levels in wheat seminal roots under waterlogging stress. Cell wall degradation-related enzymes (cellulase and pectinase) were observed using the method of ultracytochemical localization. We also tested the expression of related genes, such as histone acetyltransferase (HAT1), histone deacetylase (HD3), endoglucanase (CEL), polygalacturonase (PG), and xyloglucan endotransglucosylase (XET). The results indicated that histone acetylation is involved in eliciting responses to waterlogging stress as well as in the aerenchyma formation by affecting cell wall degradation of cortical cells in wheat seminal roots. We also present a model of waterlogging-induced aerenchyma formation in cortical cells of wheat seminal roots based on our experimental results and the findings of previous studies.