To cope with the growing world population, we will need to augment the crop production but using a sustainable agriculture, which needs to be more respectful with the environment. Thus, we will need to develop new plants that use less fertilizers, water and pesticides and are more resistant to global weather changes. Root are underground organs involved in support the plants, uptake nutrients water and to stablish relationships with soil microorganisms. In the last years, root biology has been in the focus of many research programs for their active role in plant adaptation to different environments and stress situations that are responsible for large amounts of crop losses. However, due to roots grow underground; their study has been limited and difficult. In laboratory conditions, the majority of the root research has been done growing the root in presence of light, even though they must grow in darkness (underground conditions). In this work we present a novel in vitro cultivation system, D-Root, in which root grow in darkness while the shoots grow in presence of light. Using this system we have shown that light is a negative stimulus for root growth and masks part of the responses to different conditions, including nutritional deficiencies, salt stress, and hormonal treatments. Likewise, we show that root illumination also affects to shoot development, including flowering time. An adaptation of the D-Root device has allowed us to also analyze the root growth when they are illuminated with different wavelengths. In summary, the D-Root system provides to researchers a close-to-natural (darkness) system to analyze how root growth and respond to different environments or stresses.
Figure 1: In the upper part it is shown the D-Root system, in which a squared plate is inserted into a black methacrylate box. Inside of the culture plate, a methacrylate combo is inserted to block the light coming from the top light. In the bottom, it is shown the differential response found in the root of Arabidopsi seedlings treated with the plant hormone IAA grown in presence or absence of light.