The <i>miR156‐<scp>SPL</scp>9‐<scp>DFR</scp></i> pathway coordinates the relationship between development and abiotic stress tolerance in plants

<jats:title>Summary</jats:title><jats:p>Young organisms have relatively strong resistance to diseases and adverse conditions. When confronted with adversity, the process of development is delayed in plants. This phenomenon is thought to result from the rebalancing of energy, which helps plants to coordinate the relationship between development and stress tolerance; however, the molecular mechanism underlying this phenomenon remains mysterious. In this study, we found that <jats:italic>miR156</jats:italic> integrates environmental signals to ensure timely flowering, thus enabling the completion of breeding. Under stress conditions, <jats:italic>miR156</jats:italic> is induced to maintain the plant in the juvenile state for a relatively long period of time, whereas under favorable conditions, <jats:italic>miR156</jats:italic> is suppressed to accelerate the developmental transition. Blocking the <jats:italic>miR156</jats:italic> signaling pathway in <jats:italic>Arabidopsis thaliana</jats:italic> with <jats:italic>35S::<jats:styled-content style="fixed-case">MIM</jats:styled-content>156</jats:italic> (via target mimicry) increased the sensitivity of the plant to stress treatment, whereas overexpression of <jats:italic>miR156</jats:italic> increased stress tolerance. In fact, this mechanism is also conserved in <jats:italic>Oryza sativa</jats:italic> (rice). We also identified downstream genes of <jats:italic>miR156</jats:italic>, i.e. <jats:styled-content style="fixed-case"><jats:italic>SQUAMOSA </jats:italic><jats:italic>PROMOTER </jats:italic><jats:italic>BINDING </jats:italic><jats:italic>PROTEIN</jats:italic></jats:styled-content><jats:italic>‐</jats:italic><jats:styled-content style="fixed-case"><jats:italic>LIKE</jats:italic></jats:styled-content><jats:italic> 9</jats:italic> (<jats:styled-content style="fixed-case"><jats:italic>SPL9</jats:italic></jats:styled-content>) and <jats:styled-content style="fixed-case"><jats:italic>DIHYDROFLAVONOL</jats:italic></jats:styled-content><jats:italic>‐4‐</jats:italic><jats:styled-content style="fixed-case"><jats:italic>REDUCTASE</jats:italic></jats:styled-content> (<jats:styled-content style="fixed-case"><jats:italic>DFR</jats:italic></jats:styled-content>), which take part in this process by influencing the metabolism of anthocyanin. Our results uncover a molecular mechanism for plant adaptation to the environment through the <jats:italic>miR156‐<jats:styled-content style="fixed-case">SPL</jats:styled-content>s‐<jats:styled-content style="fixed-case">DFR</jats:styled-content></jats:italic> pathway, which coordinates development and abiotic stress tolerance.</jats:p>