Project description:Purpose: The chloroplast DNA has not been primiarly analyzed in rice plants before. Hence, the objective of this study is to analyze and compare the differential methylation of chloroplast DNA in MR219 indica rice across different tissues and different developmental stages. Methods: We prepared a total of nine sodium bisulfite treated DNA libraries from three developing grain tissues, three leaf tissues at ripening stage and three leaf tissues at vegetative stage and sequenced them in Illumina Miseq platform. We performed quality trimming, alignment followed by methylation calling and differential methylation analysis using Trimmomatic v36, Bismark v16.3 and SeqMonk v40.0 on the sequencing data obtained. Statistical analysis was carried out in SeqMonk software and further validated in SPSS statistical software v22.2. Results: With an optimized data analysis workflow, we mapped around average of 26000 reads to chloroplast genome. Differential CpG and CHG methylation in SeqMonk v40.0 revealed that MR219 chloroplast DNA is differentially methylated in grain and leaf tissues and across vegetative stage and ripening stage in the leaf tissues. Chloroplast DNA from leaf at ripening stage was most methylated, followed by grain tissue and lastly leaf tissue from vegetative stage. Conclusions: Overall, it can be concluded that the organellar DNA in MR219 rice are differentially methylated at different tissues and across different developmental stages. The chloroplast DNA was most methylated in the leaf at ripening stage, followed by grain at ripening stage and leaf at vegetative stage. The functional significance of the differential methylation observed in this study needs to be investigated.
Project description:Elymus kamoji (Ohwi) S. L. Chen is a perennial herb, had high grazing value and were important forage resources, the study of E. kamoji chloroplast genome (cp genome) provides an important basis for the study of chloroplast genetic engineering and system evolution. Its chloroplast genome was 135,075 bp in length, containing a pair of inverted repeated (IR) regions (20,813 bp), separated by a large single copy region (LSC) of 80,681 bp, and a small single copy (SSC) region of 12,768 bp. Moreover, a total of 129 functional genes were annotated, including 83 mRNA, 38 tRNA genes, and 8 rRNA genes. The phylogenetic relationships of 15 species indicated that E. kamoji was closely related to Elymus sibiricus. This study might contribute to provide a theoretical basis for species identification and biological research.
Project description:Elymus alashanicus (Keng) S. L. Chen, a herbaceous plant endemic to China, plays a crucial role in the local ecosystems. In this study, we sequenced and characterized the complete chloroplast (cp) genome of E. alashanicus, which is 135,072 bp in length and arranged in a circular form. The cp genome includes a pair of inverted repeats (IRa and IRb) of 20,813 bp each, separated by a large single-copy (LSC) region of 80,678 bp and a small single-copy (SSC) region of 12,768 bp. The cp genome contains 130 genes, including 83 protein-coding genes, 39 tRNA genes, and eight rRNA genes. Phylogenetic analysis revealed that E. alashanicus is closely related to Elymus breviaristatus and Campeiostachys dahurica var. tangutorum in current sampling. Our findings provide valuable insights into the cp genome of E. alashanicus, which could contribute to further studies on the evolution and conservation of this species.
Project description:The green tea made from the etiolation shoots and leaves have fresh taste and strong aroma. ‘Zhonghuang 2 (ZH2) is a natural etiolation mutant and its shoots are etiolation in spring and turn green in summer. Two conditions including the relative high temperature (LT, 26 / 22oC) and the relative low temperature (LT, 18 / 14oC) were to find out the etiolated reason of ZH2. We confirmed ZH2 was a low-temperature sensitive tea plant cultivar, and the reason of shoots etiolation at LT was the reduction of stacked grana, which could cause the lack of photoreaction. We identified 1279 differentially expressed genes (DEGs), most of them were related to cytochrome synthesis and chloroplast development and function by RNA-seq. Through the whole-genome bisulfite sequencing (WGBS) assay, we found that the dynamic of DNA methylation level in three contexts (CG, CHG and CHH) was all decreased at LT, and the change was most obvious in the CHH context. According the result of cross analysis, 56 genes were identified with significant changes in both expression and DNA methylation levels. A large number of them were related to chloroplast development and chlorophyll synthesis. This study demonstrated that the DNA methylation was involved in the low-temperature regulated etiolation process of young shoots in ZH2. Change of the DNA methylation level was associated with the gene expression level, thus affecting the structure and function of chlorophyll and chloroplast, even reduced photosynthesis, which might have a phenotypic impact on the color of shoots and leaves. And it laid the foundation for studying the etiolation process from an epigenetic perspective.