Nefissi Ouertani Rim, Abid Ghassen, Karmous Chahine, Ben Chikha Mariem, Boudaya Oumaima, Mahmoudi Henda, Mejri Samiha, Jansen Robert K, Ghorbel Abdelwahed
Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj Cedria, BP 901, Hammam-Lif 2050, Tunisia.
Laboratory of Legumes and Sustainable Agrosystems, Centre of Biotechnology of Borj Cedria, BP 901, Hammam-Lif 2050, Tunisia.
AoB Plants. 2021 Jun 11;13(4):plab034. doi: 10.1093/aobpla/plab034. eCollection 2021 Aug.
Salt stress is considered one of the most devastating environmental stresses, affecting barley growth and leading to significant yield loss. Hence, there is considerable interest in investigating the most effective traits that determine barley growth under salt stress. The objective of this study was to elucidate the contribution of osmotic and oxidative stress components in leaves and roots growth under salt stress. Two distinct barley () salt-stress tolerant genotypes, Barrage Malleg (BM, tolerant) and Saouef (Sf, sensitive), were subjected to 200 mM NaCl at early vegetative stages. Stressed and control leaves and roots tissue were assessed for several growth traits, including fresh and dry weight and plant length, as well as the content of osmoprotectants proline and soluble sugars. In addition, malondialdehyde content and activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), as well as their corresponding gene expression patterns, were investigated. The results showed better performance of BM over Sf for leaf dry weight (LDW), root dry weight (RDW) and root length (RL). The salt-tolerant genotype (BM) had better osmoprotection against salt stress compared with the salt-sensitive genotype (Sf), with a higher accumulation of proline and soluble sugars in leaves and roots and a stronger antioxidant system as evidenced by higher activities of SOD, CAT and APX and more abundant transcripts, especially in roots. Stepwise regression analysis indicated that under salt stress the most predominant trait of barley growth was gene expression level, suggesting that alleviating oxidative stress and providing cell homeostasis is the first priority.
盐胁迫被认为是最具破坏性的环境胁迫之一，影响大麦生长并导致显著的产量损失。因此，人们对研究决定大麦在盐胁迫下生长的最有效性状有着浓厚兴趣。本研究的目的是阐明渗透胁迫和氧化胁迫成分对盐胁迫下叶片和根系生长的贡献。在营养生长早期，将两种不同的大麦耐盐基因型，即Barrage Malleg（BM，耐盐）和Saouef（Sf，敏感）置于200 mM NaCl处理下。对受胁迫和对照的叶片及根系组织进行了几种生长性状评估，包括鲜重、干重和株长，以及渗透保护剂脯氨酸和可溶性糖的含量。此外，还研究了丙二醛含量、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的活性，以及它们相应的基因表达模式。结果表明，在叶片干重（LDW）、根干重（RDW）和根长（RL）方面，BM比Sf表现更好。与盐敏感基因型（Sf）相比，耐盐基因型（BM）对盐胁迫具有更好的渗透保护作用，叶片和根系中脯氨酸和可溶性糖积累更多，抗氧化系统更强，表现为SOD、CAT和APX活性更高以及转录本更丰富，尤其是在根系中。逐步回归分析表明，在盐胁迫下，大麦生长的最主要性状是基因表达水平，这表明减轻氧化胁迫和维持细胞内稳态是首要任务。
