Speakers
Description
Copper (Cu) is an important micronutrient essential for plant growth, development, and reproductive success. In recent years, significant progress has been made toward elucidating the mechanisms of copper uptake and transport in plants. However, many gaps remain in the intracellular trafficking of Cu. In mitochondria, Cu is indispensable for mitochondrial respiration as a cofactor of electron transport chain for ATP production, but the mitochondrial copper import and export in plants is poorly understood. Here, we investigate a putative mitochondrial Cu transporter family (PHT3) in Arabidopsis and explore its function, expression, and subcellular localization. We found that PHT3;1 is expressed in the rosette leaves and flowers, PHT3;2 is predominantly expressed in mature leaves, whereas PHT3;3 is highly expressed in the flowers. Importantly, heterogenous expression of the PHT3 family members partially complemented copper-related growth defect of the yeast pic2Δ mutant, which lacks the mitochondrial Pi/Cu transporter Pic2. These findings suggest that the Arabidopsis PHT3 family is involved in mitochondrial Cu transport. To understand the physiological function of the PHT3 family in planta, we generated Arabidopsis pht3s triple mutant, which exhibited significantly delayed flowering. Our future work will leverage the advanced X-ray fluorescence imaging capabilities at CHESS to investigate Cu distribution in the pht3s mutant and further define the role of PHT3 in mitochondrial Cu homeostasis.