Rice (Oryza sativa) is one of the most widely consumed staple foods in the world. It is especially popular in Asia. Rice serves as a major source of carbohydrate to consumers. Besides that, rice provides vitamins and minerals such as magnesium and vitamin B6 to consumers (United States Department of Agriculture Agricultural Research Service, 2015).
Rice can be broadly grouped into two main subspecies: indica and japonica. The indica subspecies are long and slender, while japonica grains are short and round. Through more detailed genetic scrutiny, Garris et al. (2005) identified five distinct groups of rice: indica, aus, aromatic, temperate japonica and tropical japonica rice as shown in Figure 1 below: Figure 1: The grouping of five rice …show more content…
Epigenetic changes are those heritable changes in gene expression that do not involve any changes in a gene sequence (Holliday 2006). To put it simply, the DNA sequences coding the gene are not altered. Instead, the environment around the DNA is altered. The epigenome is the total sum of the epigenetic marks present throughout the genome of a cell (Eichten, Schmitz & Springer 2014). Epigenetic modifications are directed by many different mechanisms in plants that are influenced by various factors throughout its life cycle.
The commonly explored epigenetic mechanisms are DNA methylation and histone modification. DNA methylation is a phenomenon where a methyl (CH3) group is added to a nucleotide, often to the fifth carbon atom of a cytosine (C) ring (Eichten, Schmitz & Springer 2014) as shown in figure 2. This may cause a gene to be heavily methylated (more Cs in the sequence has attached methyl group). Hence, the gene expression is repressed which lowers the protein production. The DNA methylation can be observed at CG, CHG, or CHHG regions (H representing A or T) in plants (Zhang et al.
Rice can be broadly grouped into two main subspecies: indica and japonica. The indica subspecies are long and slender, while japonica grains are short and round. Through more detailed genetic scrutiny, Garris et al. (2005) identified five distinct groups of rice: indica, aus, aromatic, temperate japonica and tropical japonica rice as shown in Figure 1 below: Figure 1: The grouping of five rice …show more content…
Epigenetic changes are those heritable changes in gene expression that do not involve any changes in a gene sequence (Holliday 2006). To put it simply, the DNA sequences coding the gene are not altered. Instead, the environment around the DNA is altered. The epigenome is the total sum of the epigenetic marks present throughout the genome of a cell (Eichten, Schmitz & Springer 2014). Epigenetic modifications are directed by many different mechanisms in plants that are influenced by various factors throughout its life cycle.
The commonly explored epigenetic mechanisms are DNA methylation and histone modification. DNA methylation is a phenomenon where a methyl (CH3) group is added to a nucleotide, often to the fifth carbon atom of a cytosine (C) ring (Eichten, Schmitz & Springer 2014) as shown in figure 2. This may cause a gene to be heavily methylated (more Cs in the sequence has attached methyl group). Hence, the gene expression is repressed which lowers the protein production. The DNA methylation can be observed at CG, CHG, or CHHG regions (H representing A or T) in plants (Zhang et al.