Water deficiency has become a serious ecological problem facing all mankind, and drought has become a key factor constraining the development of agricultural production. Gaining insights into drought response mechanisms is vital for crop adaptation. We present, here, a multifactorial study from germination to vegetative drought stages in the model plant Brachypodium hybridum. A total of 200 genotypes representing 10 natural populations (Fayedh, Enfidha, Jbel Zaghouan, Haouaria, Raouad, Sejnen, Ain Drahem, El Kef, Daouar El Hej Wniss and Djerba) which represent almost all the bioclimatic regions in Tunisia were used. High variation in germination capacity under drought stress was found between studied populations. It reaches 100% at 250 mV for Djerba population and decrease up to 40% at 100 mV. Drought caused significant increase in oxidative stress. Interestingly, genotype 8/14 originated from El Kef exhibited the highest leaf H₂O₂ content, resulting in higher leaf MDA accumulation. Consistently, no significant changes were observed in-SOD, CAT and GPX activities in both leaves and roots, relatively to unstressed state. Different profile was recorded in 6/9 originated from Raoued in which the most pronounced levels of H₂O₂ and MDA were observed in drought stressed roots. Concurrently, root CAT activity increased by 22-fold relatively to unstressed plants. Drought stress resulted in a decrease in H₂O₂ content, mitigation of lipid peroxidation in both leaves and roots of 6/5 genotype originated from Raoued, with a simultaneous increase in leaf and root SOD activity. This was associated with enhanced GPX activity where 75 and 40% of increase were recorded in genotype 6/5 in leaves and roots.

缺水已成为全人类面临的严重生态问题，干旱已成为制约农业生产发展的关键因素。深入了解干旱响应机制对于作物适应至关重要。我们在此提出了模型植物短柄草从发芽到营养干旱阶段的多因素研究。使用了代表突尼斯几乎所有生物气候区域的 10 个自然种群（Fayedh、Enfidha、Jbel Zaghouan、Haouaria、Raouad、Sejnen、Ain Drahem、El Kef、Daouar El Hej Wniss 和 Djerba）的总共 200 个基因型。研究发现，在干旱胁迫下，不同种群的发芽能力存在很大差异。对于杰尔巴族群，它在 250 mV 时达到 100%，在 100 mV 时下降最多 40%。干旱导致氧化应激显着增加。有趣的是，源自El Kef的基因型8/14表现出最高的叶片H ₂ O ₂含量，导致更高的叶片MDA积累。一致地，相对于未胁迫状态，叶和根中的 SOD、CAT 和 GPX 活性没有观察到显着变化。源自 Raoued 的 6/9 记录了不同的情况，其中在干旱胁迫的根中观察到最显着的 H ₂ O _{2和 MDA 水平。}同时，根部 CAT 活性相对于未受胁迫的植物增加了 22 倍。干旱胁迫导致Raoued 6/5基因型H ₂ O ₂含量下降，叶和根脂质过氧化减轻，同时叶和根SOD活性增加。这与 GPX 活性增强有关，其中叶和根中的基因型 6/5 记录了 75% 和 40% 的增加。