We found that a decrease in oxygen levels in the lateral root primordia stabilizes ERF-VII transcription factors. These transcription factors then repress the expression of genes that are involved in lateral root development. This repression of gene expression contributes to the proper spacing of lateral roots. In other words, when oxygen levels are low, the ERF-VII transcription factors are not degraded, and they are able to bind to DNA and repress the expression of genes that are needed for lateral root development. This stops the growth of lateral roots and helps to ensure that they are spaced properly.
We also found that plants with mutations in the ERF-VII genes have more lateral roots. This suggests that the ERF-VIIs normally play a role in limiting lateral root development. This research is important because it helps us to understand how lateral root development is controlled at the molecular level. Lateral roots are important for plants because they help them to absorb water and nutrients from the soil. By understanding how lateral root development is controlled, we may be able to develop new ways to improve crop yields.

During my postdoc in the group of Prof. Marie Barberon in Geneva (CH), I studied a biological process which was entirely new to me: how suberin deposition is regulated at the molecular level in roots. This work demonstrated that development and plasticity of suberin barrier for selective mineral nutrient uptake in the root endodermis is tightly regulated by exogenous and developmental cues. Both cues independently control a set of four MYB transcription factors (MYB41, MYB53, MYB92 and MYB93), which can redundantly regulate suberin biosynthesis machinery. In a nutshell, my work identified the complete set of molecular regulators of suberin deposition in Arabidopsis roots. Physiological analysis of these plants has allowed me to decipher the role of suberin independently of synthetic transgenes and other endodermal barriers (Shukla et al., PNAS, 2021). This work also generated a set of genetic tools that can be used to further understand the plasticity of nutrient-specific adaptation of suberin deposition in the roots.