The Effects of Hydro-Priming and Colonization with Piriformospora indica and Azotobacter chroococcum on Physio-Biochemical Traits, Flavonolignans and Fatty Acids Composition of Milk Thistle (Silybum marianum) under Saline Conditions

Abstract

Salinity is an important challenge around the world, effecting all physiological and biochemical processes of plants. It seems that seed priming can diminish the negative impacts of salinity. To study the effects of hydro-priming and inoculation with Piriformospora indica (Pi) and Azotobacter chroococcum (Az) on physio-biochemical traits, flavonolignans and fatty acids composition of milk thistle under saline conditions, a greenhouse experiment was carried out. Our results indicated that under salinity, seed priming, especially Pi, improved physio-biochemical properties in milk thistle. Under 120 mM NaCl, inoculation with Pi increased membrane stability index (MSI) and relative water content (RWC) (by 21.86 and 33.43%, respectively). However, peroxidase (POX) (5.57- and 5.68-fold in roots and leaves, respectively), superoxide dismutase (SOD) (4.74- and 4.44-fold in roots and leaves, respectively), catalase (CAT) (6.90- and 8.50-fold in roots and leaves, respectively) and ascorbate peroxidase (APX) (5.61- and 5.68-fold in roots and leaves, respectively) activities increased with increasing salinity. Contrary to salinity, hydro-priming with Az and Pi positively altered all these traits. The highest content of the osmolytes, adenosine triphosphate (ATP) content and rubisco activity were recorded in Pi treatments under 120 mM NaCl. Stearic acid (20.24%), oleic acid (21.06%) and palmitic acid (10.48%) increased, but oil content (3.81%), linolenic and linoleic acid content (22.21 and 15.07%, respectively) decreased under saline conditions. Inoculations of Pi positively altered all these traits. The present study indicated that seed priming with Pi under 120 mM NaCl resulted in maximum silychristin, taxidolin, silydianin, isosilybin, silybin and silymarin of milk thistle seeds.

Metabolomics reveals the response of hydroprimed maize to mitigate the impact of soil salinization

“…Seed priming methods include invasive (hydro-, osmo-, halo-, solid matrix, bio- or nano-priming) and non-invasive (magneto, UV-irradiation, γ-radiation, cold plasma, electron and laser priming) processes ( Hernandez-Apaolaza, 2022 ). Among these, hydropriming offers a sustainable and low-cost means to improve seed germination and seedling emergence in salt affect soil ( Yan, 2016 ; Yaghoubian et al., 2022 ).…”

Cell-free supernatant of Devosia sp. (strain SL43) mitigates the adverse effects of salt stress on soybean (Glycine max L.) seed vigor index

“…Plants are generally very sensitive to salinity injury during the germination stage, and exposure to salt stress at early stages can retard seedling growth later, even in conditions otherwise suitable for growth. Soil salinity negatively affects the germination of seeds either by imposing osmotic stress that prevents water uptake or by hormonal imbalance ( Kumar et al., 2022 ; Shah et al., 2022 ; Yaghoubian et al., 2022a ). Our observations indicate that CFS treatment promoted soybean germination under salinity stress conditions ( Figure 4 ).…”

“…The situation with regard to soil salinization is worsening substantially faster than researchers had predicted less than a decade ago, putting the world on alert for the potential spread of salinity issues into currently unaffected regions ( Mukhopadhyay et al., 2021 ). Salinity impairs many plant functions, from the seed germination stage to final seed production; seedling emergence at the initiation phase of the lifecycle of plants is highly susceptible to salinity ( Naamala et al., 2022 ; Yaghoubian et al., 2022a ). However, once the plants are overcome the seedling stage, they are better able to cope with the adverse consequences of salinity stress ( Gholizadeh et al., 2021 ; Shah et al., 2022 ).…”

“…Therefore, optimizing germination such that it can largely overcome soil salinity effects is possible by utilizing PGPB, a promising tool for a more sustainable future. However, the crop colonization ability of most beneficial bacteria varies depending upon the host, bacterial species, and salt concentration ( Miljaković et al., 2022 ; Nigam et al., 2022 ; Sulastri et al., 2022 ; Yaghoubian et al., 2022a ). Moreover, bacterial trait–environment relationships can vary from farm to farm and from region to region, which may affect the efficacy of PGPB ( Goddard et al., 2001 ; Meena et al., 2015 ).…”

Effect of Salinity and Plant Growth Promoters on Secondary Metabolism and Growth of Milk Thistle Ecotypes

“…The achenes of the F1 generation obtained from three ecotypes were sown on 17th November (2017–2018) under control conditions. The salinity level (120 mM) [ 44 ] was applied on 11th December, and different plant growth promoters were applied via MS. Plant growth promoters, such as thiourea (250 µM) [ 45 ], moringa leaf extract (3%) [ 46 ], and ascorbic acid (500 µM) [ 47 ], were applied at predetermined levels after inducing SS during the seedling stage through irrigation (single time point). Flowering started on 10th, 20th, and 25th February in the Faisalabad, Gujranwala, and Quetta ecotypes, respectively, in 2017, while in 2018, the flowering dates were 12th and 20th January for the Faisalabad and Gujranwala ecotypes, respectively, and 30th January for the Quetta ecotype.…”