High Ambient Temperatures Inhibit Ghd7-Mediated Flowering Repression in Rice
High Ambient Temperatures Inhibit Ghd7-Mediated Flowering Repression in Rice
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DOI：
10.1093/pcp/pcab129
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发表时间：
2021-09-12
影响因子：
4.9
通讯作者：
Izawa, Takeshi
中科院分区：
文献类型：
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作者：
Nagalla, Asanga Deshappriya;Nishide, Noriko;Izawa, Takeshi
对季节变化的预测对植物的繁殖至关重要。尽管栽培面积广阔，但环境温度对水稻光周期开花的影响在很大程度上是未知的。在这里，我们首先研究了四种不同条件下的开花时间：短日或长日，高温或低温，使用栽培品种，近等基因系和突变体。我们还研究了在不同条件下，包括光脉冲后的时间动态，使用同一株系的关键花期基因的基因表达模式。除了生长速度慢导致开花延迟外，我们还发现在低温条件下，Hd1和Ghd7基因明显增强了水稻的光周期开花。我们还发现PhyB可以作为温度传感器控制Ghd7阻滞剂活性，在较低温度下抑制Ehd1， Hd3a和RFT1，可能是通过转录后调控，尽管有诱导光周期条件。此外，我们发现高温条件下Ghd7信使RNA （mRNA）的快速减少可以导致水稻开花基因RFT1 mRNA的增加。因此，多种温度感应机制可以影响水稻的光周期开花。初夏环境温度的升高可能有助于抑制Ghd7抑制因子的活性，从而导致温带气候下水稻的适当诱导。
The anticipation of changing seasons is crucial for reproduction in plants. Despite the broad cultivation area, the effects of ambient temperature on photoperiodic flowering are largely unknown in rice. Here, we first examined flowering time under four distinct conditions: short-day or long-day and high or low temperature, using cultivars, nearly isogenic lines, and mutants in rice. We also examined gene expression patterns of key flowering-time genes using the same lines under various conditions including temporal dynamics after light pulses. In addition to delayed flowering because of low growth rates, we found that photoperiodic flowering is clearly enhanced by both Hd1 and Ghd7 genes under low-temperature conditions in rice. We also revealed that PhyB can control Ghd7 repressor activity as a temperature sensor to inhibit Ehd1, Hd3a and RFT1 at lower temperatures, likely through a post-transcriptional regulation, despite inductive photoperiod conditions. Furthermore, we found that rapid reduction of Ghd7 messenger RNA (mRNA) under high-temperature conditions can lead to mRNA increase in a rice florigen gene, RFT1. Thus, multiple temperature-sensing mechanisms can affect photoperiodic flowering in rice. The rising of ambient temperatures in early summer likely contributes to the inhibition of Ghd7 repressor activity, resulting in the appropriate floral induction of rice in temperate climates.