Abstract：
Copper (Cu) is a crucial micronutrient essential for the growth and development of plants. Rice exhibits remarkable resistance to Cu deficiency, but the underlying molecular mechanisms are not well understood. In this study, we reveal that the plant\'s ability to withstand Cu deficiency is orchestrated by a transcription factor known as OsSPL9. We have demonstrated that OsSPL9 functions as a central regulator of Cu homeostasis. Disrupting OsSPL9 through knockout significantly reduces the plant\'s tolerance to Cu deficiency. As a result, the spl9 mutants exhibit reduced Cu accumulation in their shoots when compared to wild-type plants. This reduction is linked to a disruption in the transport of Cu from older leaves to younger ones. Furthermore, we show that OsSPL9 directly binds to GTAC motifs in the promoters of key genes involved in Cu uptake and transport, as well as Cu-miRNAs, and enhances their transcription under Cu-deficient conditions. Overall, our findings shed light on the molecular basis of rice resilience to Cu deficiency stress and place the transcription factor OsSPL9 as a master regulator of this response.
摘要：
铜(Cu)是植物生长和发育所必需的关键微量营养素。水稻对缺铜表现出显著的抗性，但是潜在的分子机制还没有很好的理解。在这项研究中,我们揭示了植物抵抗铜缺乏的能力是由一种称为OsSPL9的转录因子协调的。我们已经证明OsSPL9作为Cu稳态的中央调节因子。通过敲除破坏OsSPL9显著降低了植物对铜缺乏的耐受性。因此,与野生型植物相比，spl9突变体的芽中Cu积累减少。这种减少与Cu从较老的叶子到较年轻的叶子的运输中断有关。此外，我们表明，OsSPL9直接结合到GTAC基序的启动子的关键基因参与铜的吸收和运输，以及Cu-miRNA，并在铜缺乏条件下增强其转录。总的来说,我们的发现阐明了水稻对铜缺乏胁迫的恢复力的分子基础，并将转录因子OsSPL9作为该反应的主要调节因子。
