MdMYB88 and MdMYB124 Enhance Drought Tolerance by Modulating Root Vessels and Cell Walls in Apple
MdMYB88 and MdMYB124 Enhance Drought Tolerance by Modulating Root Vessels and Cell Walls in Apple
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MdMYB88 和 MdMYB124 通过调节苹果的根管和细胞壁增强耐旱性
DOI：
10.1104/pp.18.00502
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发表时间：
2018-11-01
期刊：
影响因子：
7.4
通讯作者：
Guan, Qingmei
中科院分区：
文献类型：
--
作者：
Geng, Dali;Chen, Pengxiang;Guan, Qingmei
水分亏缺是苹果（Malus x domestica Borkh.）栽培的主要限制因素之一。根系构型在植物抗旱性中起着重要作用；然而，提高苹果树耐旱性的研究工作主要集中在地上的目标。由于可视化和数据分析方面的困难，目前对干旱条件下苹果树根系结构的遗传因素和分子机制了解甚少。我们之前观察到MdMYB88及其平行体MdMYB124调节苹果树根系形态。在本研究中，我们发现MdMYB88和MdMYB124在长期干旱条件下维持根系水力传导能力方面发挥重要作用，从而有助于适应性抗旱。进一步研究发现，MdMYB88和MdMYB124通过直接结合MdVND6和MdMYB46启动子调控根木质部发育，从而影响干旱条件下靶基因的表达。此外，MdMYB88和MdMYB124在干旱条件下调节纤维素和木质素根细胞壁的沉积。综上所述，我们的研究结果为MdMYB88和MdMYB124在苹果树根系结构、根木质部发育和次生细胞壁沉积中对干旱响应的重要性提供了新的见解。
Water deficit is one of the main limiting factors in apple (Malus x domestica Borkh.) cultivation. Root architecture plays an important role in the drought tolerance of plants; however, research efforts to improve drought tolerance of apple trees have focused on aboveground targets. Due to the difficulties associated with visualization and data analysis, there is currently a poor understanding of the genetic players and molecular mechanisms involved in the root architecture of apple trees under drought conditions. We previously observed that MdMYB88 and its paralog MdMYB124 regulate apple tree root morphology. In this study, we found that MdMYB88 and MdMYB124 play important roles in maintaining root hydraulic conductivity under long-term drought conditions and therefore contribute toward adaptive drought tolerance. Further investigation revealed that MdMYB88 and MdMYB124 regulate root xylem development by directly binding MdVND6 and MdMYB46 promoters and thus influence expression of their target genes under drought conditions. In addition, MdMYB88 and MdMYB124 were shown to regulate the deposition of cellulose and lignin root cell walls in response to drought. Taken together, our results provide novel insights into the importance of MdMYB88 and MdMYB124 in root architecture, root xylem development, and secondary cell wall deposition in response to drought in apple trees.