Effects Of Drought Stress On DNA Methylation In Tauschii

In this study, two lines were used to study DNA methylation patterns in Triticum tauschii during drought stress. Along with information from GenBank, the detail of the sequence occurring DNA methylation in high drought resistance line would be identified. These results would be helpful to explore the physiological basis of yield formation and provides a theoretical basis and practical guidance for stable production of wheat under drought stress.The major results were described as follows:(1)Drought stress can lead to changes in levels and states of DNA methylation in Triticum tauschii. During the seedling stage, methylation levels were significantly increased under drought stress in the leaves of SL-1(the tolerant line), while in T-27(the general line), methylation levels were increased in the roots.(2)Based on observation and comparison of seven samples with various concentrations of PEG, we come to the following conclusions: firstly, among various materials, SL-1 has the highest resistance to drought stress. Secondly, water is an important factor affecting the length of the coleoptile during its growth. Along with increasing of the concentration of PEG, the length of the coleoptile reduced gradually. This indicates that the length of the coleoptile is correlated with drought stress. These two conclusions above help to lay a good foundation for preliminary identification, while further experiment is necessary to test whether there is a direct relationship between genotypes and changes of plants'growth caused by various drought conditions.(3)Analysis of genomic changes in DNA methylation due to MSAP markers shows that the genomic DNA cytosine methylation level in SL-1 and T-27 decreased after drought stress, and that full methylation methylation ratio is higher than that in half. This indicates that drought treatment could cause changes of DNA methylation patterns. According to the experimental data, the main form of methylation of genomic CCGG in Triticum tauschii under drought stress is the double-stranded full methylation (CmCGG), with few in semi-methylation. However, further study is necessary to confirm whether methylation modification is missing during plants'growth with drought stress, and whether this is correlated with gene expression for plants'stress tolerance.