Arid and Oases Cropping Laboratory, Arid Lands Institute (IRA), 4119, Medenine, Tunisia.
Arid and Oases Cropping Laboratory, Arid Lands Institute (IRA), 4119, Medenine, Tunisia.
Plant Physiol Biochem. 2021 Oct;167:990-998. doi: 10.1016/j.plaphy.2021.09.025. Epub 2021 Sep 21.
Hydrogen peroxide (H2O2) priming was proved to be effective to boost salt and drought stress tolerance in Capsicum annuum L. Hither, hydrotime (HT) approach, a population-based threshold model-germination dependence on water availability, was introduced to account for the effects of reduced water potential on HO-primed seeds in progress toward germination. Pre-optimized HO concentrations (1 and 10 mM for 24 h at 25 °C) were applied. Subsequently, seeds were germinated over a range of water potential (Ψ) (0 to -1.2 MPa) induced by sodium chloride (NaCl) and polyethylene glycol (PEG-6000) at 25 °C. We suggest that HO-priming affects differently the three derived items of HT model; induced lower hydrotime constant (θ) thus, revealed more rapid germination particularly evident with PEG, shifted the threshold or base water potential for 50% germination (Ψ) towards a more negative value in NaCl culture, reflected a better salinity tolerance, though, the opposite effect was recorded with PEG, and reduced the standard deviation (σ), proved a better uniformity of the germination process for both cultures. Thus, HO-priming increased GR (1/t) at all Ψ>Ψ which is due to both a lower Ψ and a smaller θ in the primed seeds for NaCl culture and primarily owing to reducing θ with no positive effect on Ψ for PEG culture. A normalized time-scale, for comparing responses, was introduced and confirmed the aforementioned impact. Therefore, the crosstalk between HO molecule and different cell pathways generates a constructive response in accordance with imposed stress.
过氧化氢 (H2O2) 引发被证明可有效提高辣椒对盐和干旱胁迫的耐受性。在此，引入了基于群体的阈值模型-水分可用性对萌发的依赖关系的 hydrotime (HT) 方法，以解释降低水势对 HO 引发种子萌发过程的影响。优化了 HO 浓度（25°C 下 24 小时 1 和 10 mM）。随后，在 25°C 下，用氯化钠 (NaCl) 和聚乙二醇 (PEG-6000) 诱导的水势 (Ψ) （0 至-1.2 MPa）范围内对种子进行萌发。我们认为，HO 引发会以不同的方式影响 HT 模型的三个派生项；诱导更低的水时常数 (θ)，从而表现出更快的萌发，特别是在 PEG 中更为明显，在 NaCl 培养物中，将引发 50%萌发的阈值或基础水势 (Ψ) 移向更负的值，反映出更好的耐盐性，尽管在 PEG 中记录了相反的效果，以及降低标准偏差 (σ)，证明了两种培养物萌发过程的均匀性更好。因此，HO 引发在所有 Ψ>Ψ 时都增加了 GR（1/t），这是由于 NaCl 培养物中引发种子的 Ψ 更低和 θ 更小，而 PEG 培养物中则主要是由于 θ 降低而 Ψ 没有积极影响。引入了一个标准化时间尺度来比较响应，证实了上述影响。因此，HO 分子与不同细胞途径之间的串扰会根据施加的应激产生建设性的反应。
