低NO_(3)^(-)胁迫抑制烟草根系质外体运输的机制研究  

Mechanism of Low NO_(3)^(-)Stress Inhibiting Apoplastic Transport in Tobacco Roots

作　　者：张标 许耘祥 张莉汶 朱莹莹 刘海伟[1] ZHANG biao;XU Yunxiang;ZHANG Liwen;ZHU Yingying;LIU Haiwei(Institute of Tobacco Research of Chinese Academy of Agricultural Sciences,Key Laboratory of Tobacco Biology and Processing,Ministry of Agriculture,Qingdao 266101,China;Graduate School of Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[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

出　　处：《中国烟草科学》2024年第2期25-34,共10页Chinese Tobacco Science

基　　金：山东省自然科学基金面上项目(ZR2023MC150);中国农业科学院科技创新工程项目(ASTIP-TRIC03)。

摘　　要：为探究低NO_(3)^(-)胁迫抑制烟草根系质外体运输的生理机制,以中烟100为试验材料,在水培条件下设计了0.01、0.1 mmol/L两个低NO_(3)^(-)胁迫处理,及4.0mmol/L正常NO_(3)^(-)浓度的对照处理,分析了各浓度NO_(3)^(-)对烟苗发育、根系形态、蒸腾作用、质外体途径运输、内皮层木栓化以及质外体屏障形成相关基因表达的影响。结果表明,低NO_(3)^(-)胁迫(0.01和0.1 mmol/L)烟苗根冠比显著大于对照,增幅分别为267%和125%,蒸腾量显著小于对照,降幅分别为176%和114%;PTS荧光强度显著小于对照,降幅分别为31%和27%,木质部伤流液以及地上部PTS浓度显著小于对照,降幅分别为105%、91%和103%、75%;低NO_(3)^(-)胁迫诱导烟草根内皮层的早期木栓化,木栓质沉积位置更靠近根尖;低NO_(3)^(-)胁迫诱导与质外体屏障形成相关基因的表达上调。综上,低NO_(3)^(-)胁迫诱导的内皮层木栓化抑制了烟草根系质外体途径运输。To explore how low NO_(3)^(-)stress affects the apoplastic pathway transport in tobacco root,two low NO_(3)^(-)stress treatments were implemented at concentrations of 0.01 and 0.1 mmol/L,while 4.0 mmol/L NO_(3)^(-)treatment served as the control.The flue-cured tobacco variety Zhongyanloo was employed as the experimental material.Various parameters including tobacco seedling development,root morphology,transpiration rate,apoplastic pathway transport,endodermal suberization,and gene expression related to apoplastic barrier formation were analyzed.The root/shoot of low NO_(3)^(-)stress(0.01 mmol/L and 0.1 mmol/L)was significantly higher than that of the control,with increases of 267%and 125%,respectively;The transpiration capacity of low NO_(3)^(-)stress was significantly lower than that of the control,with decreases of 176%and 114%,respectively;The PTS fluorescence intensity of low NO_(3)^(-);stress is significantly lower than that of the control,with the decrease of 31%and 27%,respectively.The PTS concentrations in xylem sap and shoot of low NO_(3)^(-)stress exhibited lower than that of the control,with the decrease of 105%,91%and 103%,75%,respectively.Moreover,low NO_(3)^(-),stress induced early endodermal suberization of tobacco roots,with suberin deposition observed nearer to the root tip.This stress condition meanwhile upregulated gene expression associated with apoplastic barrier formation.In summary,low NO_(3)^(-)stress-induced endodermal suberization inhibited the apoplastic pathway transport in tobacco roots.

关 键 词：低NO_(3)^(-) 胁迫 根 木栓化 质外体途径 PTS 

分 类 号：S572.01[农业科学—烟草工业]