NtPHYB1与光温信号互作调控烟草种子萌发

光照和温度是影响种子萌发的2个重要环境因子,光敏色素是光和温度的受体,研究光敏色素协同光温信号调控种子萌发对于指导作物播种具有重要意义。本研究旨在探索NtPHYB1基因型如何响应光温环境变化而调控烟草种子萌发。结果表明,15种光温条件下萌发率的均值为野生型(wildtype,WT)种子显著大于NtPHYB1-RNAi和NtPHYB1-OE种子。在持续光照下, NtPHYB1-OE种子萌发被抑制,而在黑暗下NtPHYB1-RNAi种子萌发被抑制。在15℃,3种基因型种子萌发均被抑制,NtPHYB1-OE种子萌发率最低;在20℃和25℃,光促进或抑制种子萌发作用不明显,3种基因型种子萌发率均较高,NtPHYB1-OE和WT种子达到最大萌发率;在30℃和35℃,光对于种子维持较高萌发率是必不可少的,NtPHYB1-RNAi种子达到最大萌发率。综上所述,NtPHYB1、光周期和温度三者之间在调控烟草种子萌发时存在交互作用,通过修饰NtPHYB1基因和改善播种环境均可显著提高烟草种子的萌发率。

NtPHYB1 interacts with light and temperature signal to regulate seed germina-tion in Nicotiana tabacum L.

Temperature and light are two important environmental factors affecting seed germination, and phytochromes are the sensors of light and temperature. It is of great significance to investigate the interaction of phytochromes with light and temperature to regulate seed germination for guiding crop sowing. The aim of this study is to explore how the NtPHYB1 genotype regulates seed germination in response to change in light and temperature environments in tobacco. The average germination frequency of WT seeds was significantly higher than that of NtPHYB1-OE and NtPHYB1-RNAi seeds under 15 environments. The germination of NtPHYB1-OE seeds was inhibited by continuous light exposure, while the germination of NtPHYB1-RNAi seeds was repressed by darkness. At 15℃, the germinations of all three genotypic seeds were inhibited by the low-temperature, and the germination frequency of NtPHYB1-OE seeds was significantly lower than that of WT and NtPHYB1-RNAi seeds;while there was no significant effect in light signal. At 20℃ and 25℃, the temperature signal promoted the ability of seed germination, and the signal of light was dispensable, resulting in the highest germination frequencies for NtPHYB1-OE and WT seeds. At 30℃ and 35℃, the light signal was indispensable to maintain seed germination for all three genotypic seeds, resulting in the highest germination frequency for NtPHYB1-RNAi seeds. To sum up, there were interactions among NtPHYB1, photoperiod, and temperature in the regulation of seed germination in tobacco. The germination frequencies of tobacco seeds could be significantly improved by modifying NtPHYB1 gene or improving the cultivation environment.