| Abstrakt: |
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°C, 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°C and 25°C, 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°C and 35°C, 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. [ABSTRACT FROM AUTHOR] |
