Saad Muhammad, Mary Helen, Amjid Umar, Shabir Ghulam, Aslam Kashif, Shah Shahid Masood, Khan Abdul Rehman
Department of Biotechnology, COMSATS University Islamabad, Abbottabad, Pakistan.
Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan, Pakistan.
Biol Futur. 2019 Dec;70(4):278-285. doi: 10.1556/019.70.2019.31. Epub 2019 Dec 1.
Tartary buckwheat, known for its rich source of health beneficial secondary metabolites, is cultivated in many areas of the world. Among different environmental factors, photoperiod strongly influence its growth, flowering time, and ultimately the yield. In this context, epigenetics could contribute significantly in the regulation of plant response against changing environment. Therefore, with the aim to study the involvement of DNA methylation in photoperiod mediated plant response, genome-wide DNA methylation analysis was performed in two accessions (A1 and A2) of Tartary buckwheat using three photoperiodic treatments, i.e., 10-hr light/day (T1), 12-hr light/day (T2), and 14-hr light/day (T3). Flowering time and plant fresh weight data revealed that accessions A1 and A2 prefer T1 and T2 treatments, respectively. Total DNA methylation ratio increased with the increase in photoperiod in accession A1 but decreased under same conditions in accession A2. Full methylation increased significantly while intensive decrease in hemimethylation was noted from T2 to T3 in A1, whereas full methylation strongly increased and hemimethylation strongly decreased from T1 to T2 in A2. Overall, the DNA methylation events appeared more frequently than demethylation events. This study reports for the first time an accession-/ genotype specific pattern of shift in the DNA methylation under different photoperiodic treatments that will pave the way toward identification of specific genes involved in the regulation of plant response against photoperiodic stress.
苦荞以其富含对健康有益的次生代谢产物而闻名，在世界许多地区都有种植。在不同的环境因素中，光周期强烈影响其生长、开花时间以及最终产量。在这种情况下，表观遗传学在调节植物对变化环境的反应中可能发挥重要作用。因此，为了研究DNA甲基化在光周期介导的植物反应中的作用，使用三种光周期处理，即每天10小时光照（T1）、每天12小时光照（T2）和每天14小时光照（T3），对苦荞的两个种质（A1和A2）进行了全基因组DNA甲基化分析。开花时间和植物鲜重数据显示，种质A1和A2分别偏好T1和T2处理。在种质A1中，总DNA甲基化率随光周期的增加而增加，但在种质A2中，在相同条件下却降低。在A1中，从T2到T3，全甲基化显著增加，而半甲基化则显著降低，而在A2中，从T1到T2，全甲基化强烈增加，半甲基化强烈降低。总体而言，DNA甲基化事件比去甲基化事件出现得更频繁。本研究首次报道了在不同光周期处理下，DNA甲基化变化的种质/基因型特异性模式，这将为鉴定参与调节植物对光周期胁迫反应的特定基因铺平道路。
