锌(Zn)是植物必需的微量营养素。充分调节锌的吸收,运输和分配,对锌缺乏胁迫或锌过量毒性的适应对植物的生长和发育至关重要。然而,了解植物对不同锌供应水平的分子反应很少。在本研究中,我们研究了锌完全缺乏下生长的烟草幼苗的生长和生理反应,限锌,锌-正常,和Zn-4倍充分条件,分别,并证明锌缺乏/限制导致氧化应激和烟草植物生长受损。结合转录组和蛋白质组分析揭示了与锌吸收和分布相关的基因/蛋白质的上调,包括ZIP,NAS3s,和HMA1s,以及与氧化应激调节有关的基因/蛋白质的上调,包括SODs,APX1s,GPX6和GSTs在烟草幼苗中响应锌缺乏/限制,表明烟草具有主要通过上调ZIPs-NAS3s模块来调节Zn稳态的机制,并通过激活抗氧化机制来减轻锌缺乏/限制诱导的氧化应激。我们的研究结果为烟草对不同锌供应的适应性机制提供了新的见解,为开发对缺锌具有高耐受性的烟草或其近缘种奠定了理论基础。
Zinc (Zn) is an essential micronutrient for plants. Adequate regulation of Zn uptake, transport and distribution, and adaptation to Zn-deficiency stress or Zn-excess toxicity are crucial for plant growth and development. However, little has been done to understand the molecular responses of plants toward different Zn supply levels. In the present study, we investigated the growth and physiological responses of tobacco seedlings grown under Zn-completely deficient, Zn-limiting, Zn-normal, and Zn-4-fold sufficient conditions, respectively, and demonstrated that Zn deficiency/limitation caused oxidative stress and impaired growth of tobacco plants. Combined transcriptome and proteome analysis revealed up-regulation of genes/proteins associated with Zn uptake and distribution, including ZIPs, NAS3s, and HMA1s, and up-regulation of genes/proteins involved in regulation of oxidative stress, including SODs, APX1s, GPX6, and GSTs in tobacco seedlings in response to Zn deficiency/limitation, suggesting that tobacco possessed mechanisms to regulate Zn homeostasis primarily through up-regulation of the ZIPs-NAS3s module, and to alleviate Zn deficiency/limitation-induced oxidative stress through activation of the antioxidant machinery. Our results provide novel insights into the adaptive mechanisms of tobacco in response to different Zn supplies, and would lay a theoretical foundation for development of varieties of tobacco or its relatives with high tolerance to Zn-deficiency.