Protective Effects of Nitric Oxide on Photosynthetic Stability and Performance of Silybum marianum under Water Deficit Conditions

Abstract

Core Ideas Milk thistle is a medicinal plant cultivating for production of silymarin and oil.The results our work showed that with the application of SNP photosynthesis, pigments content, and water status were improved in the drought stress condition and as a result significant increases in secondary metabolites production and grain yield was observed.Overall, this study suggest that application of 100 µM SNP and using Sari ecotype can be recommended for maximizing crop yield under drought stress in semiarid environment. Milk thistle is a medicinal plant cultivated for production of silymarin and oil. Nitric oxide as an active molecule, plays an important role in plant’s reaction to drought stress. In this study, we investigated the role of sodium nitroprusside (SNP) as a nitric oxide donor for tolerance enhancement of drought in two genotypes of milk thistle in a 2‐yr field experiment. With increasing drought severity, photosynthetic rate and stomatal conductance of milk thistle decreased significantly. The exogenous application of SNP significantly compensated for the negative effects of drought on photosynthetic rate by 40%, but also reduced stomatal conductance during 6 d after withholding irrigation. Drought stress significantly decreased pigments content and this affect was compensated by applying SNP in both genotypes. Among yield components, the number of heads per plant showed the highest sensitivity to drought stress followed by seed weight, while all yield components responded significantly to the application of SNP. Withholding irrigation significantly decreased seed yield in both genotypes and years. Averaged over 2 yr, application of 100 µM SNP in Sari ecotype at the stage of stem elongation and anthesis significantly improved seed yield by 38 and 33%, respectively, compared with the non‐application of SNP. However, in the Hungarian cultivar, SNP only led to a significant increase of 29% in seed yield during anthesis stress. Overall, this study suggest that application of SNP at a rate of 100 μM had potential to ameliorate the adverse effect of drought stress on photosynthetic rate and seed yield of milk thistle.

Effects of zinc-nano oxide, salicylic acid and sodium nitroprusside on physiological properties, antioxidant enzyme activities and secondary metabolites of Viola odorata under drought stress

“…In the present study, the foliar application of SNP on the sweet violets increased the shoot FW compared to the control. It can be due to the impact of SNP on plant tolerance improvement against stress, increasing the photosynthesis rate and water use efficiency, and increasing photosynthetic availability to sustain vegetative growth and subsequently increase the FW [Zangani et al 2018].…”

Reactive Oxygen, Nitrogen, and Sulfur Species (RONSS) as a Metabolic Cluster for Signaling and Biostimulation of Plants: An Overview

“…S. marianum contains silymarin, a mixture of flavonoid complexes with a protective component against drugs, including chemotherapy [ 178 ]. Field assays with two genotypes of S. marianum demonstrated that applying the SNP (100 µM) as a NO donor compensates for 40% of the adverse effects caused for drought stress, and all yield components responded significantly to treatment with SNP [ 179 ]. Applying 100 µM SNP also decreased malondialdehyde content and H 2 O 2 in S. marianum plants submitted to water deficit and prevented a silymarin yield reduction but increased taxifolin production, silychristin, silybin, and isosilybin B [ 180 ], compounds that have been associated with the treatment of diseases due to pharmacological properties as hepatoprotective drugs [ 181 , 182 ].…”

“…Applying 100 µM SNP also decreased malondialdehyde content and H 2 O 2 in S. marianum plants submitted to water deficit and prevented a silymarin yield reduction but increased taxifolin production, silychristin, silybin, and isosilybin B [ 180 ], compounds that have been associated with the treatment of diseases due to pharmacological properties as hepatoprotective drugs [ 181 , 182 ]. Under drought stress applying 100 µM SNP on S. marianum , the leaf photosynthesis rate increased between 80 and 100% compared with the non-treated plants [ 179 ].…”

Photosynthetic adaptation mechanisms of waterlogged wheat (Triticum aestivum) at flowering under exogenous nitric oxide donor application

“…Several hormones, such as abscisic acid (Kim et al, 2018), methyl jasmonate (Ghasem et al, 2022), salicylic acid (Koramutla et al, 2022), 6‐benzylaminopurine (Zhang et al, 2022a), ethylene (Iqbal et al, 2011), and ethephon (Wang et al, 2016) have been reported to promote grain yield in waterlogged wheat plants. In recent years, several investigations have focused on nitric oxide (NO) as a signalling molecule that plays a crucial role in enhancing waterlogging resistance in plants (Zangani et al, 2018; Zhang et al, 2021a). When wheat is subjected to flooding, its roots synthesize endogenous NO by upregulating the nitric reductase pathway (Aakanksha et al, 2017).…”