NaCl-altered oxygen flux profiles and H+-ATPase activity in roots of two contrasting poplar species
NaCl-altered oxygen flux profiles and H+-ATPase activity in roots of two contrasting poplar species
复制标题
两种对比杨树根部 NaCl 改变的氧通量分布和 H -ATP 酶活性
DOI：
10.1093/treephys/tpaa142
复制
发表时间：
2021
期刊：
影响因子：
4
通讯作者：
Chen Shaoliang
中科院分区：
文献类型：
--
作者：
Ma Xiuying;Li Jinke;Deng Chen;Sun Jian;Liu Jian;Li Niya;Lu Yanjun;Wang Ruigang;Zhao Rui;Zhou Xiaoyang;Lu Cunfu;Chen Shaoliang
维持线粒体呼吸对于证明ATP为H+泵在盐胁迫下持续排除Na+是至关重要的。以胡杨（Populuseuphratica）和杨35 -44（Populuspopulus 35 -44）为材料，研究了NaCl胁迫对两种白杨氧吸收、线粒体呼吸的影响及其与H+-ATP酶活性的关系。与P.胡杨根在NaCl胁迫（150 mM）下表现出更强的Na+分泌能力。Pb（NO_3）_2染色的细胞化学分析表明，P.在长期（LT）增加的盐胁迫（50-200 mM NaCl，4周）期间，胡杨根细胞比盐敏感白杨保持更高的H+水解活性。质子泵的长期激活需要持久的能量供应（三磷酸腺苷，ATP），这是通过有氧呼吸提供的。利用振动电极技术结合膜尖极谱氧微电极技术，研究了盐胁迫下植物根系O2吸收的种间、时空差异。NaCl冲击（150 mM）后的摄氧量在P中下降较少。胡杨popularis，虽然盐诱导的瞬态动力学是不同的急剧下降的O2引起的高渗休克（255 mM甘露醇）。短期（ST）处理（150 mM NaCl，24 h）刺激O2流入P。胡杨根和LT处理的P.胡杨根轴O2通量沿着增加，而在P中O2通量随盐度的增加而下降。人民的根O2流入的空间定位显示，顶端区比伸长区更敏感高NaCl（150，200 mM）在ST和LT应力。药理实验表明，线粒体呼吸抑制剂NaN 3抑制O2吸收时，盐胁迫下根系Na+分泌和H+-ATP酶活性相应受到抑制。因此，我们认为，稳定的线粒体呼吸激活了P.胡杨根细胞在盐环境下维持Na+稳态。
Maintaining mitochondrial respiration is crucial for proving ATP for H+pumps to continuously exclude Na+under salt stress. NaCl-altered O2uptake, mitochondrial respiration and the relevance to H+-ATPase activity were investigated in two contrasting poplar species,Populus euphratica(salt-tolerant) andPopulus popularis35-44 (salt-sensitive). Compared withP. popularis,P. euphraticaroots exhibited a greater capacity to extrude Na+under NaCl stress (150 mM). The cytochemical analysis with Pb(NO3)2staining revealed thatP. euphraticaroot cells retained higher H+hydrolysis activity than the salt-sensitive poplar during a long term (LT) of increasing salt stress (50–200 mM NaCl, 4 weeks). Long-sustained activation of proton pumps requires long-lasting supply of energy (adenosine triphosphate, ATP), which is delivered by aerobic respiration. Taking advantage of the vibrating-electrodes technology combined with the use of membrane-tipped, polarographic oxygen microelectrodes, the species, spatial and temporal differences in root O2uptake were characterized under conditions of salt stress. Oxygen uptake upon NaCl shock (150 mM) was less declined inP. euphraticathan inP. popularis, although the salt-induced transient kinetics were distinct from the drastic drop of O2caused by hyperosmotic shock (255 mM mannitol). Short-term (ST) treatment (150 mM NaCl, 24 h) stimulated O2influx inP. euphraticaroots, and LT-treatedP. euphraticadisplayed an increased O2influx along the root axis, whereas O2influx declined with increasing salinity inP. popularisroots. The spatial localization of O2influxes revealed that the apical zone was more susceptible than the elongation region upon high NaCl (150, 200 mM) during ST and LT stress. Pharmacological experiments showed that the Na+extrusion and H+-ATPase activity in salinized roots were correspondingly suppressed when O2uptake was inhibited by a mitochondrial respiration inhibitor, NaN3. Therefore, we conclude that the stable mitochondrial respiration energized H+-ATPase ofP. euphraticaroot cells for maintaining Na+homeostasis under salt environments.