Selenium seed priming enhanced the growth of salt-stressed Brassica rapa L. through improving plant nutrition and the antioxidant system.

Various abiotic stresses may affect the germination, growth, and yield of direct-seeded vegetable crops. Seed priming with effective antioxidant mediators may alleviate these environmental stresses by maintaining uniformity in seed germination and improving the subsequent health of developing seedlings. Salt-induced stress has become a limiting factor for the successful cultivation of Brassica rapa L., especially in Southeast Asian countries. The present study was performed to elucidate the efficacy of seed priming using selenium (Se) in mitigating salt-induced oxidative stress in turnip crops by reducing the uptake of Na+. In this study, we administered three different levels of Se (Se-1, 75 μmol L-1; Se-2, 100 μmol L-1; and Se-3, 125 μmol L-1) alone or in combination with NaCl (200 mM). Conspicuously, salinity and Se-2 modulated the expression levels of the antioxidant genes, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX). The upregulated expression of stress-responsive genes alleviated salt stress by scavenging the higher reactive oxygen species (ROS) level. The stress ameliorative potential of Se (Se-2 = 100 μmol L-1) enhanced the final seed germination percentage, photosynthetic content, and seedling biomass production up to 48%, 56%, and 51%, respectively, under stress. The advantageous effects of Se were attributed to the alleviation of salinity stress through the reduction of the levels of malondialdehyde (MDA), proline, and H2O2. Generally, treatment with Se-2 (100 μmo L-1) was more effective in enhancing the growth attributes of B. rapa compared to Se-1 (75 μmo L-1) and Se-3 (125 μmo L-1) under salt-stressed and non-stressed conditions. The findings of the current study advocate the application of the Se seed priming technique as an economical and eco-friendly approach for salt stress mitigation in crops grown under saline conditions.

Hussain S ，Ahmed S ，Akram W ，Li G ，Yasin NA ... -  《Frontiers in Plant Science》

Selenium-Priming mediated growth and yield improvement of turnip under saline conditions.

Hussain S ，Ahmed S ，Akram W ，Sardar R ，Abbas M ，Yasin NA ... -  《-》

Mitigation of the salinity stress in rapeseed (Brassica napus L.) productivity by exogenous applications of bio-selenium nanoparticles during the early seedling stage.

In recent years, much attention has been directed toward using nanoparticles (NPs) as one of the most effective strategies to improve plant growth, especially under salt stress conditions. Further research has been conducted to develop NPs using various chemical ways; accordingly, knowledge about the beneficial effect of bioSeNPs in rapeseed is obscure. Selenium (Se) is a vital micronutrient with a series of physiological and antioxidative properties. Seed priming is emerging as a low-cost, efficient, and environment-friendly seed treatment in nanotechnology. The current study was carried out to examine the promising effects of nanopriming via bioSeNPs on the expression level of aquaporin genes, seed microstructure, seed germination, growth traits, physiochemical attributes, and minerals uptake of two rapeseed cultivars under salinity stress conditions. Our investigation monitored the positive effects of bioSeNPs on the expression level of aquaporin genes (BnPIP1-1 and BnPIP2-1) and water uptake during the seed imbibition (4 and 8 h of priming), which indicated higher imbibition potential and germination promotion with bioSeNPs application (most effective at 150 μmol/L). The total performance index was significantly enhanced with nano-treatments in rapeseed seedlings. Collectively, nano-application improved seed microstructure, seed germination, and photosynthetic efficiency directly correlated with higher seedlings biomass, especially with a higher concentration of bioSeNPs. The enhancement in α-amylase and free amino acid contents in nanoprimed seeds resulted in rapid seed germination. Moreover, bioSeNPs increased the osmotic adjustment and enhanced the efficiency of the plant's defense system by improving the activity of enzymatic and non-enzymatic antioxidants, thus enhancing ROS scavenging under salt stress. The obtained results may indicate the strengthening of seed vigor, improving seedling growth and physiochemical attributes via bioSeNPs. Our findings displayed that bioSeNPs modulated the Na+ and K+ uptake, which improved the rapeseed growth and showed a close relationship with the low contents of toxic Na+ ion; thus, it prevented oxidative damage due to salt stress. This comprehensive data can add more knowledge to understand the mechanisms behind plant-bioSeNPs interaction and provide physiological evidence for the beneficial roles of nanopriming using bioSeNPs on rapeseed germination and seedling development under salinity stress conditions. Such studies can be used to develop simple prepackaged nano primer products, which can be used before sowing to boost seed germination and crop productivity under stress conditions.

El-Badri AM ，Batool M ，Mohamed IAA ，Wang Z ，Wang C ，Tabl KM ，Khatab A ，Kuai J ，Wang J ，Wang B ，Zhou G ... -  《-》

Seed priming by sodium nitroprusside improves salt tolerance in wheat (Triticum aestivum L.) by enhancing physiological and biochemical parameters.

The germination, seedling vigor, crop establishment and yield of agronomically important crops is negatively affected by soil salinity. The current study aimed to investigate the ability of exogenous fertigation by sodium nitroprusside (SNP) to induce salt tolerance in four high yielding wheat cultivars (Sahar-06, Punjab-11, Millat-11 and Galaxy-13) that differ in their response to salt stress in terms of biomass production, oxidative defense mechanisms and grain yield. Three levels of SNP (0, 0.1 and 0.2 mM) were used for seed soaking. During soaking the seeds were kept in the dark. After soaking for 12 h the seeds were air-dried for 5 h before sowing. Salinity caused a significant reduction in biomass and grain yield, while it increased proline (Pro), ascorbic acid (AsA), hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents. Cultivar Sahar-06 and Galaxy-13 were found more tolerant to salinity based on shoot length root fresh and dry wights, 100 grain weight, decreased MDA and H2O2 accumulation, phenolic and ascorbic acid (AsA) contents, accumulation of proline, activities of SOD, POD and CAT as compared to the other cultivars. Seed priming with SNP was effective in reducing the adverse effects of salt stress induced oxidative stress on plant biomass and grain yield in all the studied wheat cultivars, but maximum amelioration of salt stress tolerance by SNP treatment was found in cv. Sahar-06. The increased salt tolerance in wheat plants by SNP seed priming might be due to the role of NO in improving seed vigor and germination and early establishment of seedlings with better growth. 0.1 mM SNP was found the most effective in improving salt tolerance, as compared to other SNP concentations. Exogenous SNP fertigation increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and the contents of AsA, Pro and total phenolics content (TPC) in the salt stressed wheat plants. Our data indicate that SNP-priming induced salt tolerance by up-regulating the antioxidative defense mechanisms resulting in better biomass production and grain yield.

Ali Q ，Daud MK ，Haider MZ ，Ali S ，Rizwan M ，Aslam N ，Noman A ，Iqbal N ，Shahzad F ，Deeba F ，Ali I ，Zhu SJ ... -  《-》

Nitric oxide alleviates salt stress in seed germination and early seedling growth of pakchoi (Brassica chinensis L.) by enhancing physiological and biochemical parameters.

The germination and seedling vigor of crops is negatively affected by soil salinity. Nitric oxide (NO) has emerged as a key molecule involved in many physiological events in plants. The objective of present study was to evaluate the impact of exogenous sodium nitroprusside (SNP, a NO donor) at different concentrations on the seed germination and early seedling growth characteristics of pakchoi (Brassica chinensis L.) under NaCl stress. 100 mM NaCl stress markedly inhibited the seed germination potential, germination index, vitality index and growth of radicles and plumules. SNP pretreatment attenuated the salt stress effects in a dose-dependent manner, as indicated by enhancing the characteristics of seed germination and early seedling growth parameters, and the mitigating effect was most pronounced at 10 μM SNP. Efficient antioxidant systems were activated by SNP pre-treatment, and which effectively increased the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), and reduced contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) and the production rate of superoxide anion radical (O2·-) in radicles and plumules, thereby preventing oxidative damage from NaCl stress. SNP pre-treatment also increased the contents of proline and soluble sugar in radicles and plumules under NaCl stress. In addition, SNP pre-treatment significantly increased the K+ contents and decreased Na+ contents in radicles and plumules, resulting in the increased level of K+/Na+ ratio. Our results demonstrated that SNP application on pakchoi seeds may be a good option to improve seed germination and seedling growth under NaCl stress by modulating the physiological responses resulting in better seed germination and seedling growth.

Ren Y ，Wang W ，He J ，Zhang L ，Wei Y ，Yang M ... -  《-》