Chitosan nanoparticle and pyridoxine seed priming improves tolerance to salinity in milk thistle seedling

Abstract

Application of growth regulators plays important role under salt conditions. Perspectives to overcome these limitations by chitosan nanoparticle (CSNP: 0, 0.25, 0.5, and 1%) and pyridoxine (PN: 0, 0.03, 0.06, and 0.09%) seed priming was studied in both experiments with milk thistle seeds exposed to NaCl as salt stress (0, 50, 100, and 150 mM). Salinity threshold and EC50 (the salinity level that 50% of germination reduction) achieved 74.85 and 213.5 mM, respectively. A significant reduction in germination percentage (49.12%), seedling length (50.07%), and seedling vigor index (67.39%) while, a significant increase in superoxide dismutase activity (54.63%) were achieved at 150 mM NaCl in compared to the control treatment. The highest germination rate was resulted by 100 mM NaCl and 0.25% CSNP and the least (2.86 seed/day) by 150 mM NaCl and without CSNP. The salt stress significantly decreased photosynthetic pigments; however, the largest value of chlorophyll a, b, and total was related to without NaCl and 1% CSNP and the least value of traits (6.1, 1.67, and 7.77 µg/g FW) to non-application of CSNP under 150 mM NaCl. PN application was caused decrease in free proline content compared to the non-application treatment. The most pronounced effects of CSNP and PN were recorded in 0.25 and 0.09% concentrations, respectively. The finding of this study leads to the conclusion that seed priming with CSNP and PN by improving physiological mechanisms such as photosynthetic pigment synthesis, antioxidant enzyme activities, and free proline content increased salt tolerance in milk thistle seedling.

Chitosan, chitosan nanoparticles and modified chitosan biomaterials, a potential tool to combat salinity stress in plants

“…Soil salinity is one of the main problems in arid and semiarid areas that affect the growth and productivity by interfering with the nutritional status of plants through complex interaction mechanisms. The typical salt challenged plants to exhibit reduced nutrient absorption, poor transport of nutrients from roots to shoots, decreased dry leaf and stunted root growth, degradation of leaf pigments like chlorophyll and carotenoids affecting photosynthetic machinery, and causing a reduction in overall growth (Ashour, Esmail, & Kotb, 2020;Mosavikia, Mosavi, Seghatoleslami, & Baradaran, 2020;Safikhan, Khoshbakht, Chaichi, Amini, & Motesharezadeh, 2018;Sen, Chouhan, Das, Ghosh, & Mandal, 2020;Zayed, Elkafafi, Zedan, & Dawoud, 2017). Reactive oxygen species (ROS) are reactive molecules that cause oxidative stress, damage to proteins and nucleic acids, produce excess malondialdehyde (MDA) by inactivating antioxidant enzymes and ultimately causes cell death under salt stress (Sheikhalipour et al, 2021).…”

“…In fact, various applications of Cs-NPs have been found to increase salinity tolerance in plants (Sen et al, 2020;Sheikhalipour et al, 2021;Zayed et al, 2017). It is even more interesting to see the composition of CsBMs in mitigating the deleterious effect of salt stress on bitter melon (Sheikhalipour et al, 2021), maize (Oliveira et al, 2016), milk thistle (Mosavikia et al, 2020), and periwinkle (Hassan et al, 2021). Despite using CsBMs alone to improve the productivity and quality of several crops, the use of modified CsBMs gained more advantage.…”

Sugar beet (Beta vulgaris L.) germination indices and physiological properties affected by priming and genotype under salinity stress

“…Generally, Mosavikia et al (2020) concluded that limited stomatal conductance, diminished activities of carbon fixation enzymes, reduced quantities of photosynthetic pigments, and destruction of photosynthetic apparatus are among the key factors limiting the process of photosynthesis under salinity stress conditions.…”

“…Enzymatic and non-enzymatic antioxidants response are defensive mechanisms to overcome oxidative stress (Demidchik, 2015). Proline and sugar, non-enzymatic antioxidants response, are known to act as an osmolyte/osmoprotectant agent under drought or salinity stress (Mosavikia et al, 2020). The osmolyte has an important role in scavenging free radicals, osmotic pressure adjustment, stabilizing sub-cellular structures, and storing carbon and nitrogen (Gorzi et al, 2017).…”

“…In this process, one interesting approach to the question of the ameliorative effects of priming solutions on stress tolerance is that seed priming with nutrients or hormones can also result in alleviated oxidative stress (Subramanyam et al, 2019). Seed priming as a pre-sowing technique can improve radicle emergence, germination percentage (GP), germination rate (GR), SVI, seedling establishment, and yield by making changes in metabolic activities in the seeds of many crops (Mosavikia et al, 2020). The effectiveness of seed priming depends on the plant species, the type and concentration of priming solution, the priming duration, and temperature and storage conditions (Aghighi Shahverdi et al, 2017;Khaing et al, 2020).…”