Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan.
PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
Plant Physiol. 2022 Aug 1;189(4):2357-2367. doi: 10.1093/plphys/kiac227.
In vascular plants, roots anchor themselves into the soil and take up water and nutrients to provide them to the shoots. Therefore, continuous growth and development of the roots are important for plant life. To achieve this, photosynthesizing leaves must be able to supply sufficient photoassimilates to the roots. However, the mechanisms by which plants maintain carbon levels in roots remain elusive. Here, we focused on the Arabidopsis (Arabidopsis thaliana) CLAVATA3/ESR-related 2 (CLE2) peptide, which was detected in Arabidopsis xylem exudate, and its homologs. CLE2 and CLE3 genes responded to carbon-deficient conditions. Loss- and gain-of-function mutant analyses showed that CLE genes positively affected root sucrose level. Mutations in the CLE genes resulted in a high shoot/root ratio under sucrose-free conditions. Grafting experiments demonstrated the systemic effect of CLE peptide genes. These findings provide insights into the molecular basis for the relationship between roots and leaves in maintenance of the root sucrose levels and growth.
在维管植物中，根固定在土壤中，并吸收水分和养分，为地上部分提供水分和养分。因此，根的持续生长和发育对植物的生命至关重要。为了实现这一目标，进行光合作用的叶片必须能够向根部提供足够的光合产物。然而，植物维持根中碳水平的机制仍不清楚。在这里，我们关注的是拟南芥（Arabidopsis thaliana）CLAVATA3/ESR-related 2（CLE2）肽，它在拟南芥木质部渗出液及其同源物中被检测到。CLE2 和 CLE3 基因对碳缺乏条件有反应。缺失和获得功能的突变体分析表明，CLE 基因对根中蔗糖水平有积极影响。CLE 基因突变导致在无糖条件下地上/根比值升高。嫁接实验证明了 CLE 肽基因的系统效应。这些发现为根和叶在维持根中蔗糖水平和生长方面的关系提供了分子基础的见解。
