To be in Petri or in soil, that is the question (Mol Plant)

Frequently, research on root growth in Arabidopsis has been carried out in transparent Petri dishes, although in the natural environment the soil-buried root actually grows in complete darkness. It is an essential question to check if experimental results reflect the natural growth of plants. It is well-known that when phosphate is deficient in a Petri dish, the primary root growth of Arabidopsis is inhibited. Recently Zheng et al. reported the molecular mechanism of how phosphate deficiency reshapes primary root growth in Petri dishes. The breakthrough is that actually the inhibited growth of primary root is just a phenotype of Arabidopsis to adapt to the blue light illumination of Petri. When grown in soil the primary root can elongate without inhibition. This discovery is not only of biological importance, but also raise a question whether the previous results obtained from Petri dish-grown Arabidopsis seedlings should be reevaluated. (Summary by Nanxun Qin) Molecular Plant 10.1016/j.molp.2019.08.001