Search

Silybum marianum (L.) Gaertn (Asteraceae) is a well-known medicinal plant enriched with antioxidative properties beneficial for liver-related diseases. The experiment was conducted to explore the effect of different PGPs as soil-supplied mode to modulate the growth-related attributes, gas exchange parameters, and antioxidative efficiency of different milk thistle ecotypes such as Faisalabad (FSD), Gujranwala (GUJ), Quetta (QTA), and Kallar Kahar (KK) under saline stresses conditions (NaCl 120 mM/irrigation water). After salinity development, ascorbic acid (AsA), thiourea (TU), and moringa leaf extract (MLE) were soil supplied with 500 µM, 250 µM, and 3% concentrations, respectively. Data conferring the growth parameters elucidate significant reduction in all growth parameters and pigment contents under salinity stress. The effect of PGPs effectively upregulates the activity of these enzymatic antioxidants and improved salt tolerance to saline field conditions with numerous additional stresses, and the order of improvement was AsA, followed by MLE and TU. The percent increase with AsA treatment was noted as GR (34.78), DHAR (1.73), MDHAR (11.83), soluble sugar (8.78), amino acid (7.47), and free proline 15.75, while percent decrease in H2O2 content was 20.56 as compared to control plants. QTA and FSD ecotypes were observed as salt-tolerant ecotypes compared to GUJ and KK. [ABSTRACT FROM AUTHOR]

Cadmium (Cd+2) is a potential and widespread toxic environmental pollutant, mainly derived from a rapid industrial process that has inhibitory effects on growth, physiological, and biochemical attributes of various plant species, including medicinal plants such as Silybum marianum L. Gaertn commonly known as milk thistle. Plant signaling molecules, when applied exogenously, help to enhance/activate endogenous biosynthesis of potentially important signaling molecules and antioxidants that boost tolerance against various abiotic stresses, e.g., heavy metal stress. The present study documented the protective role of salicylic acid (SA;0.25 μM) and hydrogen peroxide (H2O2; 10 μM) priming, foliar spray, and combinational treatments in reducing Cd+2 toxicity (500 μM) in milk thistle grown at two diverse ecological zones of Balochistan Province of Pakistan i.e., Quetta (Qta) and Turbat (Tbt). The morpho-physiological and biochemical attributes of milk thistle were significantly affected by Cd+2 toxicity; however, priming and foliar spray of SA and H2O2 significantly improved the growth attributes (root/shoot length, leaf area, and root/shoot fresh and dry weight), photosynthetic pigments (Chl a , b , and carotenoids) and secondary metabolites (Anthocyanin, Soluble phenolics, and Tannins) at both altitudes by suppressing the negative impact of Cd+2. However, the oxidative damage parameters, i.e., MDA and H2O2, decreased astonishingly under the treatment of signaling molecules, thereby protecting membrane integrity under Cd+2 stress. The morphological variations were profound at the low altitude (Tbt) as compared to the high altitude (Qta). Interestingly, the physiological and biochemical attributes at both altitudes improved under SA and H2O2 treatments, thus hampered the toxic effect of Cd+2. These signaling compounds enhanced tolerance of plants under heavy metal stress conditions with the consideration of altitudinal, and ambient temperature variations remain to be the key concerns. [ABSTRACT FROM AUTHOR]

Silybum marianum (L.) Gaertn (Astraceae) is a well-reputed medicinal plant mostly utilized for silymarin (Sily) content and oil production, however, the information about Sily contents in achene part is still fragmented under different climatic conditions. In this study four milk thistle ecotypes from Faisalabad (FSD), Gujranwala (GUJ), Quetta (QTA), and Kallar kahar (KK) having an altered achene color were analyzed under salt stress. Application of plant growth promoters (PGPs) is one of the solution for ameliorating the effect of salinity and increasing the quantity and quality traits of milk thistle, so ascorbic acid (AsA), thiourea (TU), and moringa leaf extract (MLE) were soil supplied after developing salinity stress (120 mM with irrigation) at germination stage. Predetermined levels were selected for PGPs such as AsA (500 µM), MLE (3%), and TU (250 µM). Results revealed that all yield related attributes were significantly decreased, while secondary metabolites, pericarp epidermis, pericarp parenchyma, and pericarp seed integument increased under salinity stress. Data suggested that PGPs treatment was helpful to alleviate the deleterious effects of salinity stress and enhance the milk thistle quality and quantity parameters. The ecotypic variations with altered achene color patterns represent an advantage for QTA ecotypes for higher Sily extraction under salt stressed conditions. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the effect of different plant growth promoters (PGPs) such as ascorbic acid (500 μM), thiourea (250 μM) and moringa leaf extract (3%) to mitigate salinity stress (120 mM NaCl) in four different milk thistle [ Silybum marianum (L.) Gaertn.] ecotypes from Faisalabad (FSD), Gujranwala (GUJ), Kallar Kahar (KK), and Quetta (QTA) under field conditions for two years (2017–2018). In the present study, oxidative stress indicators such as malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2) and activities of different antioxidant enzymes and levels of non-enzymatic antioxidants were significantly differed among ecotypes, salinity, and PGPs. Supplementation with ascorbic acid and moringa leaf extract improved antioxidant defense machinery during the acclimation process against salinity, and milk thistle ecotypes represent their background of ecological zones and inherent tendency to face and confronting stress with improving antioxidant levels to a significant extent in varying ways. Ecotypic variations showed that QTA ecotype Followed by FSD, GUJ, and KK had more antioxidant capacity, with minimum reactive oxygen species production. Interestingly, the correlation data revealed that MDA and H 2 O 2 had a positive correlation with each other and showed a negative correlation with all the enzymatic and non-enzymatic antioxidants. • Salinity stress induced oxidative damage and hampered growth-related attributes. • PGPs application improves enzymatic antioxidants involved in Asada-Halliwell pathway. • Interrelationship exist between ROS and antioxidant machinery for confronting salt stress. • Milk thistle anti-oxidative system showed significant variations in different ecotypes. [ABSTRACT FROM AUTHOR]