During seedling germination under the soil surface, HYPONASTIC LEAVES 1 regulates apical hook development by modulating the formation of an auxin gradient.

中文翻译：

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在顶端钩中正确建立生长素梯度需要 HYPONASTIC LEAVES 1

在土壤表面下的幼苗萌发过程中，HYPONASTIC LEAVES 1 通过调节生长素梯度的形成来调节顶端钩的发育。