Micromorphological and Anatomical Responses of Native Dicots to Industrial Effluents Released From Contaminated Region of the Chenab River in Pakistan

Abstract

Faisalabad industrial units discharge effluents and associated toxic chemicals into the environment, deteriorating ecological conditions and ecosystem health. Morphoanatomical changes in some medicinally important native species (Calotropis procera, Eclipta alba, Phyla nodiflora, and Ranunculus sceleratus) exposed to heavy industrial pollution gained evaluation. These species of choice were due to their widespread distribution in the area. Ten sites selected in the River Chenab, Chiniot, had three near point source pollution of Faisalabad industries within the 500-m radius (polluted) at three drains and two sites inside the river after each drain point source with the control site at 14 km after from the first industrial drain point source. The general response of all plants to effluents was growth retardation. Plant height increased significantly in all species from river sites. An increase in tallness was more prominent in species like C. procera and P. nodiflora. An increase in stem sclerification in C. procera and E. alba from polluted sites occurred, which indicated a better ability to tolerate industrial pollution. Remarkable increases in stem and leaf epidermis, intensive stem sclerenchyma, and closely packed stem vascular bundles in C. procera appeared, which could increase resistance to industrial pollution. Most of the morphoanatomical parameters notably attained a decrease in E. alba, the most vulnerable species. Plant survival depends on particular structural changes in dermal, mechanical, parenchymatous, and vascular tissues. Overall, industrial pollution adversely impacts plant morphological and micromorphological features, although the reaction of specific species to industrial contamination varies. The study determined that stem and leaf anatomical features, such as, epidermis size and storage tissue thickness, are suitable morphoanatomical markers for industrial pollution biomonitoring. Internal modifications of plants vegetating different industrial contaminated sites played a significant role in high tolerance levels.