Combined Kinetin and Spermidine Treatments Ameliorate Growth and Photosynthetic Inhibition in Vigna angularis by Up-Regulating Antioxidant and Nitrogen Metabolism under Cadmium Stress.

Mohammad Abass Ahanger,Parvaiz Ahmad,Abdulaziz Alsahli,Usman Aziz,Mohammed Nasser Alyemeni

doi:10.3390/biom10010147

Mohammad Abass Ahanger, Parvaiz Ahmad + Show 3 more

Open Access

https://doi.org/10.3390/biom10010147

Copy DOI

Abstract

Pot experiments were conducted to investigate the probable beneficial role of the individual as well as combined application of kinetin (50 μM Kn) and spermidine (200 μM Spd) on Vigna angularis under cadmium (Cd) stress. Cd treatment reduced growth by declining the content of chlorophylls and carotenoids, photosynthesis, and gas exchange parameters. Exogenously, Kn and Spd application enhanced the photosynthetic parameters and up-regulated the antioxidant system by improving the activities of antioxidant enzymes and the content of non-enzymatic components. In addition, the application of Kn and Spd resulted in significant improvement in the content of sugars, proline, and glycine betaine, ameliorating the decline in relative water content. Oxidative stress parameters including hydrogen peroxide, superoxide, lipid peroxidation, lipoxygenase activity, and electrolyte leakage increased due to Cd stress; however, the application of Kn and Spd imparted a significant decline in all these parameters. Further, reduced Cd uptake was also observed due to Kn and Spd application. Total phenols and flavonoids also increased due to Kn and Spd treatments under normal as well as Cd stress conditions, which may have further helped with the elimination of reactive oxygen species. Reduction in the activity of nitrate reductase and the content of nitrogen was ameliorated due to the exogenous application of Kn and Spd. Therefore, the exogenous application of Kn and Spd benefited Vigna angularis counteracting the damaging effects of Cd stress by up-regulating the tolerance mechanisms, including antioxidant and osmolyte metabolism.

Highlights

Plants are sessile and continuously exposed to several environmental threats, resulting in a considerable reduction in growth and yield
The height and dry weight was reduced by 31% and 35% respectively due to Cd, while a maximal amelioration of 33% and 37% was observed due to Kn + Spd treatment over the Cd-stressed seedlings (Table 1)
Cd accumulation was reduced by 39%, 36%, and 61% in the shoots and by 20%, 27%, and 37% in the roots due to Kn, Spd, and Kn + Spd treatment respectively over the Cd-stressed plants (Table 1)

Summary

Introduction

Plants are sessile and continuously exposed to several environmental threats, resulting in a considerable reduction in growth and yield. Once entering into the food chain through the plant system, heavy metals can affect the human population by damaging different organs. Among the toxic heavy metals, cadmium (Cd) is added to soil from natural and anthropogenic sources, thereby affecting the existing flora [1]. Occurring tolerance mechanisms that include the antioxidant system, the accumulation of compatible osmolytes, and secondary metabolites are employed to counteract the damaging effects of stresses [6,8]. Efficient working of the antioxidant system, osmolyte, and secondary metabolite metabolism results in the quick elimination of ROS from different cellular components for better stress amelioration and growth maintenance [2,10]. The accumulation of Cd in edible plant parts degrades yield quality and results in serious health hazards to humans and other animals

Methods

Results

Discussion

Conclusion