Effect of cadmium stress on seed germination, plant growth and hydrolyzing enzymes activities in mungbean seedlings

Abstract

Both protein and starch hydrolysis contribute to the effective mobilization of seed reserves to trigger seed germination. We studied the activities of hydrolytic enzymes in germinating seeds of mung bean (Vigna radiata) exposed to cadmium stress at 0, 25, 50, 75, 100 mg.L-1. Exposure to Cd stress decreased the seed germination rate and early seedling growth traits, including root and shoot length and plant fresh and dry biomass compared to control. The adverse effects of Cd were more prominent in terms of shoot length than root length. Seedling α-amylase and protease activities exhibited significant reductions with increasing Cd dose. We also recorded Cd-induced reduction in total soluble proteins and sugars while the concentration of free amino acids exhibited an increase. Above all, a decrease in the hydrolysis process of reserve carbohydrates, proteins and impaired reserve translocation contributed to the inhibition of seedlings’ germination and early growth traits.

Melatonin as a key regulator in seed germination under abiotic stress

“…170,171 Moreover, solute leakage from embryo, higher activity of lipoxygenase, elevated ROS production, reduction in cell elasticity, altered cell division are amongst other HMs induced negative effects during SG. [171][172][173] MEL confers HMs tolerance in plants especially during SG by regulating several key physiological processes 174 including enhanced GSH pool, 175 higher endogenous MEL levels, reestablishment of redox homeostasis, 176 and higher endogenous contents of reducing and soluble sugars in germinating seeds. 177,178 Furthermore, MEL application also upregulated the gene expression relating to MEL biosynthesis and phytochelatin synthesis 179 and increased proline accumulation under HMs stress.…”

“…Different HMs reduce SG by disrupting the activity of α‐amylase proteases and hydrolytic enzymes, 169 increasing the accumulation of HMs in newly developed tissues, inhibiting hydrolysis of carbohydrates and translocation of sugars to new developing cells 170,171 . Moreover, solute leakage from embryo, higher activity of lipoxygenase, elevated ROS production, reduction in cell elasticity, altered cell division are amongst other HMs induced negative effects during SG 171–173 …”

Effect of plant growth regulators on rice plants (Oryza sativa L.) growth under cadmium stress

“…______________________ *Corresponding author: agilan.b.r. @gmail.com Elevated Cd levels in plants' environment cause reductions in stem size, internode number, both wet and dry biomass, inflorescence size, as well as leaf size, leading to diminished photosynthesis and transpiration rates [6][7][8].…”

Nitric oxide promotes adventitious root formation in cucumber under cadmium stress through improving antioxidant system, regulating glycolysis pathway and polyamine homeostasis

“…Some studies have also shown that excessive accumulation of ROS under Cd stress can trigger protein post-translational modification ( Gzyl et al., 2015 ), enzyme inactivation and denaturation, DNA and RNA damage, resulting in cell damage and cell death ( Singh et al., 2016 ). These series of reactions may aggravate the degree of lipid peroxidation ( Heyno et al., 2008 ), disrupts metabolic activities and eventually affect plant growth and development ( Yu et al., 2015 ; Anwar et al., 2021 ; El Rasafi et al., 2022 ). It has been demonstrated that plants have a series of antioxidant defense system to mitigate the oxidative damage caused by ROS ( Gill and Tuteja, 2010 ).…”