%A LI Zeng-Qiang, DING Xin-Chao, LU Hai, HU Ya-Li, YUE Jiao, HUANG Zhen, MO Liang-Yu, CHEN Li, CHEN Tao, CHEN Peng %T Physiological characteristics and DNA methylation analysis under lead stress in kenaf (Hibiscus cannabinus L.) %0 Journal Article %D 2021 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2021.04104 %P 1031-1042 %V 47 %N 6 %U {https://zwxb.chinacrops.org/CN/abstract/article_7111.shtml} %8 2021-06-12 %X

DNA methylation plays an important role in response to plant biotic and abiotic stresses, but there are few reports on the changes of plant DNA methylation level under lead stress. In this study, kenaf (Hibiscus cannabinus L.) P3A was used as the material, the seedlings were cultured in Hoagland solution, and treated with at different concentrations (0, 200, 400, and 600 μmol L -1) of PbCl2. The changes of agronomic traits, ROS content and antioxidant enzyme activity of root were investigated. The changes of DNA methylation level in roots under 600 μmol L -1 lead stress were determined by methylation-sensitive amplification polymorphism (MSAP). The differentially methylated genes (DMGs) were cloned, sequenced, and functionally annotated. In addition, the expression levels of DMGs were investigated by qRT-PCR. The results showed that the stem diameter, root length and root surface area of seedlings were significantly inhibited by different concentrations of PbCl2 stress. And the plant height and total fresh weight of kenaf seedlings were significantly reduced under 400 μmol L -1 concentration or more of lead stress. The content of lead, O2 ? and MDA, and activities of SOD were increased significantly in kenaf seedlings roots, CAT activity increased first and then decreased with the increase of lead concentration, the POD activity showed a trend of decreasing first and then increasing. MSAP analysis of roots treated with 0 μmol L -1 and 600 μmol L -1 PbCl2 showed that DNA methylation rates were 71.13%, 62.20%, fully methylated ratio was 50.52%, 37.80%, and hemi-methylated ratio were 20.62%, 24.40%, respectively. In other words, lead stress significantly reduced DNA methylation rate and total methylation rate, whereas increased the hemi-methylation rate of roots of kenaf seedlings. qRT-PCR analysis showed that there were also differences in gene expression of seven DMGs closely related to resistance. It suggested that the change of DNA methylation level played an important role in kenaf response to lead stress in kenaf. This study provides a theoretical basis for further exploring the potential mechanism of DNA methylation in response to plant abiotic stress, and improving soil lead pollution in kenaf production.