植物学报 ›› 2025, Vol. 60 ›› Issue (6): 914-930.DOI: 10.11983/CBB24191  cstr: 32102.14.CBB24191

• 研究论文 • 上一篇    下一篇

不同钾水平下烟草根内皮层木栓化的适应性发育差异

许耘祥1,2, 张莉汶1,2, 王朋1, 顾迎晨1,2, 张标1,2, 朱莹莹1, 刘海伟1,*()   

  1. 1 中国农业科学院烟草研究所/农业农村部烟草生物学与加工重点实验室, 青岛 266101
    2 中国农业科学院研究生院, 北京 100081
  • 收稿日期:2024-12-09 接受日期:2024-03-18 出版日期:2025-11-10 发布日期:2025-03-18
  • 通讯作者: 刘海伟
  • 基金资助:
    中国烟草总公司山东省公司科技重大专项(202417);山东省自然科学基金(ZR2023MC150);中国农业科学院科技创新工程(ASTIP-TRIC03)

Differences in the Adaptive Development of Suberin in the Tobacco Root Endothelial Layer under Different Potassium Levels

Yunxiang Xu1,2, Liwen Zhang1,2, Peng Wang1, Yingchen Gu1,2, Madan Lal Kolhi1,2, Biao Zhang1,2, Yingying Zhu1, Haiwei Liu1,*()   

  1. 1 Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture and Rural Affairs/Institute of Tobacco Research of CAAS, Qingdao 266101, China
    2 Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2024-12-09 Accepted:2024-03-18 Online:2025-11-10 Published:2025-03-18
  • Contact: Haiwei Liu

摘要: 根内皮层分化的质外体屏障在植物抗逆和养分吸收过程中均发挥重要作用, 其中木栓层发育为近年的研究热点。以烟草(Nicotiana tabacum)栽培品种中烟100为材料, 通过0.1-4.0 mmol∙L-1钾浓度梯度水培实验, 探讨供钾水平对根内皮层木栓化发育的影响及其生理和分子机制。结果表明, 低钾胁迫(0.1 mmol∙L-1)显著增强内皮层木栓化: 完全木栓化区域绝对长度由对照的0-2 cm延长至4-6 cm, 相对占比从0-15.0%提升至33.2%-44.3%, 表明木栓化是烟草响应低钾胁迫的关键形态适应机制之一。表型分析显示, 低钾胁迫下植株根系伸长但生物量下降, 地上部与根系钾离子含量及积累量均减少, 木质部伤流液流量及钾离子运输效率降低。内源激素含量检测发现, 低钾胁迫提高根系内源脱落酸含量, 并降低乙烯和茉莉酸甲酯含量, 形成特异性激素调控网络。转录组数据进一步佐证木栓化发育的分子基础, 木栓质合成与转运相关基因(如CYP86GPATABCG)及其上游正调控基因MYB36/41/92/93显著上调表达。综上, 该研究阐明了低钾胁迫下烟草通过脱落酸介导的激素信号调控木栓化发育程序, 为解析作物钾胁迫适应机制提供了全新视角。

关键词: 木栓化, 钾, 根内皮层, 激素

Abstract: INTRODUCTION: Apoplastic barriers differentiated from the root endoderm play important roles in plant stress resistance and nutrient uptake, and the development of suberin lamellae has become a popular research topic in recent years.
RATIONALE: Hydroponic experiments with potassium concentrations ranging from 0.1 to 4.0 mmol∙L-1 were conducted, using the cultivated tobacco variety Zhongyan 100 as the experimental material, to explore the effects of different potassium supplies on the endodermal suberization and its physiological and molecular mechanisms.
RESULTS: Low potassium (0.1 mmol∙L-1) stress significantly enhanced the endodermal suberization: the absolute length of the fully suberized region ranged from 0-2 cm in the control to 4-6 cm, and the relative proportion increased from 0-15.0% to 33.2%-44.3%. These findings indicate that suberization is one of the key morphological adaptation mechanisms in tobacco under low potassium stress. Phenotypic analysis revealed that under low potassium stress, root elongation increased while plant biomass decreased, and the potassium ion content and accumulation in both the aboveground and root parts decreased. Additionally, the flow rate and potassium ion concentration in the xylem sap decreased, indicating reduced transport efficiency. Endogenous hormone analysis revealed that low potassium stress increased the abscisic acid (ABA) content in roots while suppressing ethylene and methyl jasmonate levels, forming a specific hormonal regulatory network. The transcriptome data further supported the molecular basis of suberization development, showing significant upregulation of genes related to suberin synthesis and transport (e.g., CYP86, GPAT, and ABCG) and their upstream positive regulatory factors (MYB36, MYB41, MYB92, and MYB93).
CONCLUSION: This study is the first to reveal that low potassium stress regulates the suberization developmental program of tobacco roots through ABA-mediated hormonal signaling reprogramming, providing a novel perspective for understanding the adaptation mechanisms of plants to potassium stress.

Fluorescence imaging of transverse sections of the endodermis development in tobacco roots under three potassium concentrations (bars=130 μm)

Key words: suberization, potassium, root endodermis, hormone