Transient Heat Stress During Early Seed Development Primes Germination and Seedling Establishment in Rice
Transient Heat Stress During Early Seed Development Primes Germination and Seedling Establishment in Rice
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DOI：
10.3389/fpls.2018.01768
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发表时间：
2018-12-05
影响因子：
5.6
通讯作者：
Walia, Harkamal
中科院分区：
文献类型：
--
作者：
Begcy, Kevin;Sandhu, Jaspreet;Walia, Harkamal
水稻产量对温度升高高度敏感。鉴于全球气温上升的趋势，这种对高温的敏感性对实现全球粮食安全构成了挑战。水稻种子的早期发育对不利的环境条件高度敏感。此阶段的热应激 (HS) 会降低种子大小和生育力，从而降低产量。在这里，我们探讨了早期种子发育过程中 HS 对种子活力、发芽和建立的跨代表型影响。为了阐明 HS 对合子后水稻种子发育事件的影响，我们在受精后 1 天开始进行中度（35 摄氏度）和重度（39 摄氏度）HS 处理，并维持 24、48 或 72 小时。瞬时 HS 处理改变了胚乳 (ED) 细胞化的起始、种子大小和/或小穗成熟的持续时间。值得注意的是，与来自在对照或严重 HS 下生长的植物的种子相比，暴露于 24 和 48 小时中等 HS 的种子表现出更高的发芽率。短期的 HS 导致早期种子发育过程中赤霉素 (GA) 和 ABA 生物合成基因的表达发生改变，以及成熟时 GA 和 ABA 水平以及淀粉含量的改变。 24 小时的中等 HS 后发芽率增加可能是由于 ABA 敏感性改变和/或淀粉水平增加。我们关于短暂性 HS 对激素稳态影响的研究结果提供了一个实验框架来阐明潜在的分子和代谢途径。
Rice yield is highly sensitive to increased temperature. Given the trend of increasing global temperatures, this sensitivity to higher temperatures poses a challenge for achieving global food security. Early seed development in rice is highly sensitive to unfavorable environmental conditions. Heat stress (HS) during this stage decreases seed size and fertility, thus reducing yield. Here, we explore the transgenerational phenotypic consequences of HS during early seed development on seed viability, germination, and establishment. To elucidate the impact of HS on the developmental events in postzygotic rice seeds, we imposed moderate (35 degrees C) and severe (39 degrees C) HS treatments initiated 1 day after fertilization and maintained for 24, 48, or 72 h. The transient HS treatments altered the initiation of endosperm (ED) cellularization, seed size and/or the duration of spikelet ripening. Notably, seeds exposed to 24 and 48 h moderate HS exhibited higher germination rate compared to seeds derived from plants grown under control or severe HS. A short-term HS resulted in altered expression of Gibberellin (GA) and ABA biosynthesis genes during early seed development, and GA and ABA levels and starch content at maturity. The increased germination rate after 24 of moderate HS could be due to altered ABA sensitivity and/or increased starch level. Our findings on the impact of transient HS on hormone homeostasis provide an experimental framework to elucidate the underlying molecular and metabolic pathways.