Influence of Selenium on Growth, Physiology, and Antioxidant Responses in Maize Varies in a Dose-Dependent Manner

Munaza Naseem,Mohamed A El-Esawi,Adnan Mustafa,Hina Ahmed Malik,Jalil Ahmad,Hina Sattar,Muhammad Awais,Naila Farooq,Xiukang Wang,Muhammad Anwar-Ul-Haq,Daniel Cozzolino

doi:10.1155/2021/6642018

Abstract

There is a very narrow margin in selenium deficiency and toxicity although it is an important element for humans, animals, and plants. Effects of selenium (Se) on the growth and physiomorphological parameters in maize were studied grown in soil spiked with sodium selenate (Na2SeO4) in 5 different concentrations (i.e., 0. 2.5, 5.0, 10.0, and 20.0 mg kg−1). The growth of plants was affected by high Se concentration. However, maximum increases in plant height and root length were observed at low Se (2.5 mg kg−1) which were 17.89 and 23.17%, respectively. At higher Se concentrations (20 mg kg−1), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters. The dry matter of plants was also analyzed for nutrient (Fe and Zn) concentrations. Results indicated that Se stress inhibits plant growth. Gas exchange parameters were also found to be decreased under stress conditions, but at a lower Se level (2.5 mg kg−1), improvement in transpiration rate (63.46%), photosynthetic rate (47.47%), and stomatal conductance (54.55%) was observed. The reduction in growth attributes may be due to the high accumulation of Se in roots and the disturbance in gas exchange parameters. However, the principal component analysis revealed that higher Se levels were more hazardous for maize growth and physiological responses as compared to low Se levels.

Highlights

IntroductionAt higher Se concentrations (20 mg kg−1), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters
Munaza Naseem,1 Muhammad Anwar-ul-Haq,1 Xiukang Wang,2 Naila Farooq,3 Muhammad Awais,1 Hina Sattar,1 Hina Ahmed Malik,1 Adnan Mustafa,4 Jalil Ahmad,5 and Mohamed A
It was observed that the growth rate was faster at low selenium treatments and slowed down with increasing selenium concentration. e maximum increase in shoot length (17.89%) was noted where the Se was applied at the rate of 2.5 mg kg−1 as compared to control treatment

Summary

Introduction

At higher Se concentrations (20 mg kg−1), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters. Given the industrial revolution since the 19th century, there is an increased pressure on water resources and the overall environment that leads to soil pollution with heavy metals [3, 4]. Some of these metals are important for plant growth as micronutrients such as copper (Cu) [5]. Selenium enters the environment through natural and anthropogenic sources like weathering of rocks and volcanoes [11] while the anthropogenic sources and agricultural practices that raise selenium stacking in soil comprise irrigation and utilization of organic fertilizers like manures [12]

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Results

Conclusion