Rasool Mir Heena, Kumar Yadav Shiv, Ercisli Sezai, Al-Huqail Asma A, Soliman Dina A, Siddiqui Manzer H, Alansi Saleh, Yadav Sangita
Division of Seed Science and Technology, ICAR- Indian Agricultural Research Institute, New Delhi 110012, India.
Department of Horticulture, Ataturk University, Erzurum 25240, Turkey.
Saudi J Biol Sci. 2021 May;28(5):2634-2640. doi: 10.1016/j.sjbs.2021.02.068. Epub 2021 Mar 1.
Inadequate plant stand establishment due to insufficient germination is an important bottleneck in achieving the potential yields, specifically under uncertain growing conditions. Hydropriming has been publicized as a useful tool to alleviate the stress-induced consequences. Association of DNA biosynthesis in hydroprimed seeds of maize; hybrid, PEHM 5 and its parental lines (CM150 and CM151) was studied. Seeds were hydroprimed at 25 °C for 30 h and half of them were surface dried while the other half were redried back to the original moisture contents. The treated and untreated seeds were evaluated for; germination test, mean germination time, vigour index and DNA levels in embryos of fully matured seeds. Both the treatment strategies significantly enhanced the planting value of maize seeds. Vigour index I revealed significant correlation with G2/G1 ratio whereas significant negative correlation between G2/G1 ratio and mean germination time was observed. Large amounts of 2C DNA signals in flow cytometric analysis divulged that most cells might had arrested in the cell cycle at the pre synthetic G1 phase of nuclear division. Augmentation of 4C signal in the embryonic region was noticed after imbibition that could be ascribed to cells entering the synthetic phase of nuclear division. The embryonic cells showed increased 4C:2C ratios after 30 h of imbibition. Apparently, DNA synthesis preceded germination. In dry seeds, DNA histograms revealed both a 2C signal and a considerable 4C peak. A priming period of 30 h in distilled water considerably enhanced the rate and uniformity of germination in both surface dried and redried treatment strategies. Upon priming, the ratio of 4C:2C increased during the 30 h priming period, though the level in case of redried seeds did not reach the level obtained after hydration in water without drying back. However, the 4C: 2C ratio was constant after redrying the seeds to the original moisture content, indicating that the chromosomal material in the embryonic cells had stably ceased cell cycle activity at the G2 phase. The present results indicate that the beneficial effects of priming on seedling performance could be associated with the action of replicative DNA synthesis processes prior to germination.
由于发芽不足导致的植株建立不充分是实现潜在产量的一个重要瓶颈，特别是在不确定的生长条件下。水引发已被宣传为一种减轻胁迫诱导后果的有用工具。研究了玉米杂交种PEHM 5及其亲本系（CM150和CM151）水引发种子中DNA生物合成的关联。种子在25℃下水引发30小时，其中一半进行表面干燥，另一半重新干燥至原始水分含量。对处理过和未处理的种子进行了发芽试验、平均发芽时间、活力指数和完全成熟种子胚中的DNA水平评估。两种处理策略均显著提高了玉米种子的种植价值。活力指数I与G2/G1比率呈显著正相关，而G2/G1比率与平均发芽时间之间呈显著负相关。流式细胞术分析中大量的2C DNA信号表明，大多数细胞可能在核分裂的合成前G1期停滞在细胞周期中。吸胀后在胚区域观察到4C信号增强，这可能归因于细胞进入核分裂的合成期。吸胀30小时后，胚细胞的4C:2C比率增加。显然，DNA合成先于发芽。在干种子中，DNA直方图显示既有2C信号又有相当大的4C峰。在蒸馏水中30小时的引发期显著提高了表面干燥和重新干燥处理策略下的发芽率和均匀性。引发后，在30小时的引发期内4C:2C比率增加，尽管重新干燥种子的水平未达到在水中水化后未回干所获得的水平。然而，将种子重新干燥至原始水分含量后，4C:2C比率保持恒定，表明胚细胞中的染色体物质在G2期已稳定停止细胞周期活动。目前的结果表明，引发对幼苗性能的有益影响可能与发芽前复制性DNA合成过程的作用有关。
