Ikeya Shun, Aoyanagi Takuya, Ishizuka Imari, Takeuchi Ayano, Kozaki Akiko
Department of Biological Science, Faculty of Science, Shizuoka University, 836 Ohya Suruga-ku, Shizuoka 422-8529, Japan.
Kato Gakuen Gyoshu High School, Numazu 410-0011, Japan.
Plants (Basel). 2020 Jun 2;9(6):707. doi: 10.3390/plants9060707.
Seed germination, one of the most important stages in a plant's life cycle, can be affected by abiotic stresses, such as salinity. The plant hormone abscisic acid (ABA) and high concentrations of glucose are also known to inhibit germination. In contrast, nitrate is known to stimulate germination in many plants. However, this stimulatory effect has not yet been investigated in the presence of inhibitory effects caused by abiotic stresses, ABA, and glucose. In this study, we show that nitrate can alleviate the inhibitory effects of sodium chloride (NaCl) or high concentrations of glucose on seed germination in , while it was not able to promote germination that was inhibited by exogenous ABA and mannitol (an inducer of osmotic stress). An analysis of the gene expression involved in the regulation of germination showed that encoding the gibberellin (GA) synthesis enzyme, (), encoding a bHLH transcription factor, and encoding an ABA catabolic enzyme, were significantly upregulated by the addition of KNO in the presence of NaCl or glucose. Our results suggest the possibility that these genes are involved in the nitrate-mediated control of seed germination in the presence of NaCl or glucose.
种子萌发是植物生命周期中最重要的阶段之一，会受到非生物胁迫的影响，比如盐度。植物激素脱落酸（ABA）和高浓度葡萄糖也会抑制种子萌发。相反，硝酸盐能刺激许多植物的种子萌发。然而，在非生物胁迫、ABA和葡萄糖所产生的抑制作用存在的情况下，这种刺激作用尚未得到研究。在本研究中，我们发现硝酸盐可以缓解氯化钠（NaCl）或高浓度葡萄糖对[植物名称未给出]种子萌发的抑制作用，而它无法促进由外源ABA和甘露醇（一种渗透胁迫诱导剂）所抑制的种子萌发。对参与萌发调控的基因表达分析表明，编码赤霉素（GA）合成酶的[基因名称未给出]、编码bHLH转录因子的[基因名称未给出]以及编码ABA分解代谢酶的[基因名称未给出]，在NaCl或葡萄糖存在的情况下，通过添加硝酸钾（KNO₃）而显著上调。我们的结果表明，在NaCl或葡萄糖存在的情况下，这些基因可能参与了硝酸盐介导的种子萌发调控。
