PJB-2024-1559
Ultraviolet induced endophytic Aspergillus tamari SK12 revealed faster growth and modulation of physiochemical attributes of okra under copper stress
Sufaid Khan, Muhammad Hamayun, Anwar Hussain, Sumera Afzal Khan, Sajid Ali, Shumaila Siraj, Abdulwahed Fahad Alrefaei, Zahid Ali Butt and Hamza Bacha
Abstract
In today’s world, the most serious environmental and biological problem is the contamination of agricultural lands by the heavy metals. Copper is an essential element for the normal growth of plants but its concentration can build up in soil to a level that can adversely affect plant growth. Endophytic fungi associate with plants and improve their fitness to tolerate environmental stresses. In this work, a plant growth promoting and copper tolerant endophytic fungus, Aspergillus tamari SK12, isolated from plants in contaminated areas was exposed to ultraviolet irradiation for various durations. The UV irradiated variant (UIV) showed superior growth in the absence and presence of Cu than the wild type strain. Higher biomass produced by the UIV was accompanied by greater quantities of IAA, SA, Phenols and flavonoids, enabling this strain to tolerate Cu more efficiently. Fungal capabilities to alleviate Cu stress in Abelmoschus esculentus. When okra seedlings were exposed to 750 ppm of Cu, root and shoot growth were reduced to 64% and 30.4% of the control. Both the wild type and UIV endophytes were beneficial for the growth of okra seedlings where growth remained higher than the control even in the presence of 750 ppm of Cu. The mutant strain effectively colonized roots of seedlings and absorption of copper from soil to root was also cut down to 50% of the wild SK12. The UIV colonized seedlings also kept ROS levels in normal range with the help of peroxidase enzyme and the non-enzymatic antioxidants i.e. Phenols and flavonoids. The UIV inoculated also accumulated up to higher levels of IAA and SA than control and wild strain. These Hormones increases ROS scavenging by increasing antioxidant activities and protect seedlings against Cu stress by reducing lipid peroxidation and the malondialdehyde levels. All these features enabled the endophyte (UIV) associated seedlings to grow normally even in the presence of 750ppm of Cu. We concluded that UIV strain had the ability to alleviate Cu stress in okra seedlings in multiple way; from reducing its uptake to improved ROS scavenging system through enhanced antioxidant activities and modulation of IAA and SA
To Cite this article:
Khan, S., M. Hamayun, A. Hussain, S.A. Khan, S. Ali, S. Siraj, A.F. Alrefaei, Z.A. Butt and H. Bacha. 2024. Ultraviolet induced endophytic Aspergillus tamari SK12 revealed faster growth and modulation of physiochemical attributes of okra under copper stress. Pak. J. Bot., 56(5): DOI: http://dx.doi.org/10.30848/PJB2024-5(37)
Download
