Mamedi Arash, Sharifzadeh Farzad, Maali-Amiri Reza, Divargar Fatemeh, Rasoulnia Abdolrahman
Department of Agronomy and Plant Breeding, Faculty of Agriculture and Natural Resources, University of Tehran, P.O Box: 3158711167, Karaj, Iran.
Physiol Mol Biol Plants. 2022 Jan;28(1):251-274. doi: 10.1007/s12298-022-01125-3. Epub 2022 Jan 21.
Salinity restricts seed germination and seedling growth through induction of osmotic and oxidative stresses. Therefore, this study aimed to enhance salinity tolerance in quinoa seed by pre-optimized osmo-priming treatments of CaCl (10 mM, 10 °C, 10 h) and KNO (150 mM, 5 °C, 24 h). The results showed that these treatments developed the cellular defense mechanisms in seeds as 'priming memory' that could improve the physiological and biochemical responses to salinity in post-priming stages. The germination capacity and seedling growth decreased with increasing salinity that was accompanied with a higher content of MDA and HO. However, the improvement of primed seed vigor against high salinity was explained by increasing the biological defense mechanisms including antioxidant enzymes (CAT, APX, SOD, GPX and PPO) and antioxidant metabolites (DPPH antioxidant activity, phenolics, flavonoids, ascorbic acid), particularly in presence of salt stress. In addition, Ca and K priming acquired salinity tolerance in post-priming stages through a significant increase in the accumulation of proline, glycine-betaine, soluble carbohydrate. Improvement in homeostasis of K/Na ratio by promoting K maintenance and Na exclusion was also found in post-priming stages. These observations may be utilized as effective methods in improving salinity tolerance of quinoa seed germination in saline agriculture by improving the antioxidant system, osmolyte accumulation and mineral nutrient homeostasis.
盐分通过诱导渗透胁迫和氧化胁迫来限制种子萌发和幼苗生长。因此，本研究旨在通过对氯化钙（10 mM，10 °C，10小时）和硝酸钾（150 mM，5 °C，24小时）进行预优化的渗透引发处理，提高藜麦种子的耐盐性。结果表明，这些处理在种子中形成了细胞防御机制，即“引发记忆”，可以改善引发后阶段对盐分的生理和生化反应。随着盐度的增加，发芽能力和幼苗生长下降，同时丙二醛（MDA）和过氧化氢（H₂O₂）含量升高。然而，引发种子对高盐度的活力提高可以通过增强生物防御机制来解释，包括抗氧化酶（过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPX）和多酚氧化酶（PPO））和抗氧化代谢物（1,1-二苯基-2-苦基肼（DPPH）抗氧化活性、酚类、黄酮类、抗坏血酸），尤其是在盐胁迫存在的情况下。此外，钙和钾引发在引发后阶段通过脯氨酸、甘氨酸甜菜碱、可溶性碳水化合物积累的显著增加获得了耐盐性。在引发后阶段还发现通过促进钾的维持和钠的排除，钾/钠比的稳态得到改善。这些观察结果可作为有效方法，通过改善抗氧化系统、渗透调节物质积累和矿质营养稳态，提高盐碱农业中藜麦种子萌发的耐盐性。
