Drought-hardening improves drought tolerance in Nicotiana tabacum at physiological, biochemical, and molecular levels

BMC Plant Biology

Shahen Shah¹  Aaqib Shaheen²  Yuanhua Wu³  Xinghua Ma³  Shusheng Wang³  Lixia Xiao³  Rayyan Khan⁴  Xiaoying Wu⁴ 

[1] Department of Agronomy, The University of Agriculture Peshawar, 25130, Peshawar, Pakistan;Key Laboratory of Plant Stress Biology, State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 475004, Kaifeng, China;Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture, 266101, Qingdao, China;Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture, 266101, Qingdao, China;Graduate School of Chinese Academy of Agricultural Sciences, 100081, Beijing, China;

关键词: Tobacco;    Nicotiana tabacum;    Drought-hardening;    Drought tolerance;    Varieties;    Antioxidant enzymes;    Gene expression;    SnRK2;    AREB;    DREB;   

DOI  :  10.1186/s12870-020-02688-7

来源: Springer

【 摘 要 】

BackgroundDrought stress is the most harmful one among other abiotic stresses with negative impacts on crop growth and development. Drought-hardening is a feasible and widely used method in tobacco seedlings cultivation. It has gained extensive interests due to its role in improving drought tolerance. This research aimed to investigate the role of drought-hardening and to unravel the multiple mechanisms underlying tobacco drought tolerance and adaptation.ResultsThis study was designed in which various drought-hardening treatments (CK (no drought-hardening), T1 (drought-hardening for 24 h), T2 (drought-hardening for 48 h), and T3 (drought-hardening for 72 h)) were applied to two tobacco varieties namely HongHuaDaJinYuan (H) and Yun Yan-100 (Y). The findings presented a complete framework of drought-hardening effect at physiological, biochemical, and gene expression levels of the two tobacco varieties under drought stress. The results showed that T2 and T3 significantly reduced the growth of the two varieties under drought stress. Similarly, among the various drought-hardening treatments, T3 improved both the enzymatic (POD, CAT, APX) and non-enzymatic (AsA) defense systems along with the elevated levels of proline and soluble sugar to mitigate the negative effects of oxidative damage and bringing osmoregulation in tobacco plants. Finally, the various drought-hardening treatments (T1, T2, and T3) showed differential regulation of genes expressed in the two varieties, while, particularly T3 drought-hardening treatment-induced drought tolerance via the expression of various stress-responsive genes by triggering the biosynthesis pathways of proline (P5CS1), polyamines (ADC2), ABA-dependent (SnRK2, AREB1), and independent pathways (DREB2B), and antioxidant defense-related genes (CAT, APX1, GR2) in response to drought stress.ConclusionsDrought-hardening made significant contributions to drought tolerance and adaptation in two tobacco variety seedlings by reducing its growth and, on the other hand, by activating various defense mechanisms at biochemical and molecular levels. The findings of the study pointed out that drought-hardening is a fruitful strategy for conferring drought tolerance and adaptations in tobacco. It will be served as a useful method in the future to understand the drought tolerance and adaptation mechanisms of other plant species.Graphical abstractDrought-hardening improved drought tolerance and adaptation of the two tobacco varieties. T1 indicates drought-hardening for 24 h, T2 indicates drought-hardening for 48 h, T3 indicates drought-hardening for 72 h

【 授权许可】

CC BY