Increased levels of the hormone auxin usually promote cell growth in plant tissues. Chinese scientists, together with researchers from the Institute of Science and Technology Austria (IST Austria), have now shown that in special areas of the seedling, increased auxin levels trigger a different gene expression pathway leading to growth inhibition. The discovery, published in the journal Nature, helps to explain the formation of the typical bend or so called apical hook that helps the seedling to break through the soil following germination.