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

Sumera Anwar,Zaib-un- Nisa,Naila Ali,Fahad Shafiq,Muhammad Yasin Ashraf,Uzma Usman

doi:10.1590/2317-1545v43256006

Abstract

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.

Highlights

In cereals, endosperm development and its physiological roles have been well documented
The embryo scutellum synthesizes and secrete gibberellin, a germination-promoting hormone, into the aleurone layer of the endosperm. It enhances the synthesis of hydrolytic enzymes in the aleurone layer (Yan et al, 2014). Hydrolytic enzymes such as α-amylase, protease, and acid phosphatases accelerate the process of seed germination and seedlings’ establishment
In this study, we investigated the effect of cadmium stress on seed germination, biomass, metabolites, and activities of some hydrolyzing enzymes such as α-amylase and protease were investigated

Summary

Introduction

Endosperm development and its physiological roles have been well documented. The embryo scutellum synthesizes and secrete gibberellin, a germination-promoting hormone, into the aleurone layer of the endosperm. It enhances the synthesis of hydrolytic enzymes in the aleurone layer (Yan et al, 2014). Hydrolytic enzymes such as α-amylase, protease, and acid phosphatases accelerate the process of seed germination and seedlings’ establishment. In Sorghum bicolor seeds, reduction in hydrolyzing enzyme activities such as in acid phosphatase, α-amylase, and protease has been reported under Cd stress which suggests a reduction in the storage mobilization process. A reduction of α-amylase activity has been observed, which reduced starch release from cotyledons (Kalai et al, 2016). The leakage of amino acids and soluble sugars due to loss of membrane integrity is another indication of alteration in the remobilization process observed in seeds of Vicia faba and Pisum sativum (Rahoui et al, 2010b; Basahi, 2021)

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Conclusion