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International Conference on

Recent Trends in Environmental Sustainability

ESCON22/ETERM/01
Growth and physiological response of maize (Zea mays L.) against combined toxicity of
arsenic and boron under salt stress and its amelioration by potassium

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Muhammad Mubashar Iqbal , Javaid Akhtar , Muhammad Ansar Farooq 2*
1 Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad
2 Institute of Environmental Sciences and Engineering (IESE), School of Civil and
Environmental Engineering (SCEE), National University of Sciences & Technology (NUST),
Sector H-12, Islamabad 44000, Pakistan
Correspondence: ansar_1264@yahoo.com; ansar@iese.nust.edu.pk
Abstract

Salinity and relatively high boron (B) often co-occur in agricultural environments limiting plant
growth severely. Use of arsenic (As) contaminated irrigation water and soils further decrease
the growth of cereal crops. While potassium (K) is known to enhance plant tolerance under
both stress and non-stress conditions. A hydroponic experiment was conducted to study the
interactive effect of B (1.5 and 3 mM) and As (20 and 40 µM) under saline conditions (60 mM)
and ameliorative role of K (6 and 12 mM) on maize crop. Toxicity of B and As either alone or
in combination, inhibited the plant growth which was further elevated by salt stress. However,
combined toxicity of salinity, B and As surprisingly did not decrease the growth and
physiological attributes of maize varieties. Exogenously applied K ameliorated the toxic effects
of As and salt stress by improving the growth and the physiological attributes of maize.
However, plants showed varied response to the ionic concentration under individual and
combined stresses. Increasing B and As stress increased the shoot Na and B, however, shoots
accumulated lesser B as compared to roots. 20 µM As in combination with 1.5 mM B decreased
shoot K while increasing exogenous K supply improved K uptake and accumulation in shoots.
Under combined stress of salinity, As and B, shoot B and Na continued to increase which was
significantly reduced by application of K (12 mM). It was concluded that As and B interaction
under salinity decreased the maize growth, however, this interaction was not as damaging as
compared to their individual levels and K has ameliorated the adverse effects of salinity and
As stress.
Keywords: Arsenic; Growth; Toxicity; Salt stress.

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

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