The global dynamic of DNA methylation in response to heat stress revealed epigenetic mechanism of heat acclimation in Saccharina japonica

Abstract

Saccharina japonica is an ecologically and economically important kelp in cold‐temperate regions. When it is cultivated on a large scale in the temperate and even subtropical zones, heat stress is a frequent abiotic stress. This study is the first attempt to reveal the regulatory mechanism of the response to heat stress from the perspective of DNA methylation in S. japonica. We firstly obtained the characteristics of variation in the methylome under heat stress, and observed that heat stress caused a slight increase in the overall methylation level and methylation rate, especially in the non‐coding regions of the genome. Secondly, we noted that methylation was probably one of factors affecting the expression of genes, and that methylation within the gene body was positively correlated with the gene expression (rho = 0.0784). Moreover, it was found that among the differentially expressed genes regulated by methylation, many genes were related to heat stress response, such as HSP gene family, genes of antioxidant enzymes, genes related to proteasome‐ubiquitination pathway, and plant cell signaling pathways. This study demonstrated that DNA methylation is involved in regulating the response to heat stress, laying a foundation for studying the acclimation and adaptation of S. japonica to heat stress from an epigenetic perspective.

Genome-wide identification and analysis of HECT E3 ubiquitin ligase gene family in Saccharina japonica and a comparative analysis with five other algae

“…The expression and possible function of SjHECTs for the young sporophyte under heat stress were also explored based on the published (Liu 2023) and some unpublished transcriptomic data in our laboratory. Brie y, the young sporophytes of S. japonica were collected and cultured in ltered sterilized natural seawater at 10 ± 1°C and under 35 ± 5 umol•m − 2 s − 1 light with a photoperiod of 10 h light and 14 h dark.…”

“…High temperature is one of the very serious stress factors in the commercial production of kelp, which often leads to problems such as reduced yield, increased disease risk and shortened growth period (Liu et al 2019). Previous studies found that the expression of ubiquitinases (E1, E2 and E3) in S. japonica was changed after high temperature stress, suggesting that ubiquitinases may play an important role in the resistance to heat stress in S. japonica (Liu 2023;Liu et al 2014).…”