Plant DNA methylation is sensitive to parent seed N content and influences the growth of rice

Abstract

Background Nitrogen (N) is an important nutrient for plant growth, development, and agricultural production. Nitrogen stress could induce epigenetic changes in plants. In our research, overexpression of the OsNAR2.1 line was used as a testing target in rice plants with high nitrogen-use efficiency to study the changes of rice methylation and growth in respond of the endogenous and external nitrogen stress. Results Our results showed that external N deficiency could decrease seed N content and plant growth of the overexpression line. During the filial growth, we found that the low parent seed nitrogen (LPSN) in the overexpression line could lead to a decrease in the filial seed nitrogen content, total plant nitrogen content, yield, and OsNAR2.1 expression (28, 35, 23, and 55%, respectively) compared with high parent seed nitrogen (HPSN) in high nitrogen external supply. However, such decreases were not observed in wild type. Furthermore, methylation sequencing results showed that LPSN caused massive gene methylation changes, which enriched in over 20 GO pathways in the filial overexpression line, and the expression of OsNAR2.1 in LPSN filial overexpression plants was significantly reduced compared to HPSN filial plants in high external N, which was not shown in wild type. Conclusions We suggest that the parent seed nitrogen content decreased induced DNA methylation changes at the epigenetic level and significantly decreased the expression of OsNAR2.1, resulting in a heritable phenotype of N deficiency over two generations of the overexpression line.

The Influence of Parental Heat-Stress Priming on Drought-Tolerant Maize Progenies’ Field Performance

“…The stress memories of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) plants exposed to heat or water stress were passed down to the second filial generations who were not exposed to the stress [5,12,13]. Rice grown in an N-deficient environment also passed on the stress memory to its second generation [14,15]. In these studies, progenies from primed ancestors outperformed control ancestors in a stressful environment.…”

“…The higher values recorded in important attributes such as EP, CWt, and GWt in WE3128 may be an indication of adaptive stress memory, even though there were no significant differences in most of the yield attributes measured in the maize varieties' progenies. The formation and transfer of stress-memories is genotype-dependent [14,26].…”

“…Under such a stressful environment, plants change their physiology to adapt to the new environment. These phenotypic changes have been shown to influence progenies even in second generations that were not exposed to the stress [9,14,15,29].…”

“…Fan, et al [14] investigated the effect of N deficiency in rice and found reduced growth and yield in stressed parents and their progenies, even when the progenies were grown in N-sufficient conditions. They hypothesised that the progenies inherited their stressed parents' stress memory, which hampered their growth and development in stressfree environments.…”

“…In these studies, progenies from primed ancestors outperformed control ancestors in a stressful environment. However, there were no significant differences between the progenies in a stress-free environment [5,12,14,15]. Therefore, parental priming can help reduce crop yield losses due to stress by improving plant stress tolerance.…”