Abstract
The common practice of cultivating rice through transplanting requires considerably higher amount of water, which poses several challenges, particularly in the present era of global climate change and decreasing availability of water. The direct-sown rice (DSR) presents a promising/resource-saving alternative for cultivation of rice in the current scenario of changing climatic conditions. While some local cultivars are well-adapted for DSR, there has been limited success in breeding for DSR varieties. This is mainly because of the lack of comprehensive knowledge about the adaptability of rice to changing climatic conditions. Comprehensive analysis of methylome and transcriptome profiles of rice [Nagina-22 (N-22) and IR-64] grown by transplanting as well as direct-sowing deciphered epigenetic regulation of genes involved in adaptive plasticity. Expression of a large number of genes correlated with DNA (de)methylation in N-22 under DSR conditions implies that (de)methylation of DNA base is associated with the adaptation of N-22 to DSR conditions. Hypomethylation of genes in leaves of N-22 showing their up-regulated expression under DSR conditions suggests epigenetic modification to be a key factor in adaptive plasticity of N-22. Post-translational modification of proteins, particularly histone modifications, and changes in chromatin architecture contribute to adaptability of N-22 under adverse climatic conditions. The finding might help in developing more resilient/efficient DSR cultivars suitable for changing global climate.
Keywords
Oryza sativa, Direct-sowing, Adaptability, DNA methylation, Gene × environment interaction