Pollution from heavy metals is a global problem that is very dangerous to the environment. Among the heavy metals, cadmium is receiving more and more attention because it is one of the most ecotoxic, making it very harmful for biological activity in soil, biodiversity, plant metabolism, and human and animal health. | Turkish Journal of Agriculture and Forestry Research Article Turk J Agric For (2015) 39: 272-276 © TÜBİTAK doi: Auxin-mediated growth of rice in cadmium-contaminated soil Hussna FAROOQ, Hafiz Naeem ASGHAR*, Muhammad Yahya KHAN, Muhammad SALEEM, Zahir Ahmad ZAHIR Institute of Soil & Environmental Sciences, University of Agriculture Faisalabad, Pakistan Received: Accepted: Published Online: Printed: Abstract: Pollution from heavy metals is a global problem that is very dangerous to the environment. Among the heavy metals, cadmium is receiving more and more attention because it is one of the most ecotoxic, making it very harmful for biological activity in soil, biodiversity, plant metabolism, and human and animal health. Phytohormones, produced by plants, control or regulate germination, growth, metabolism, or other physiological activities, and they can alleviate the toxic effects of heavy metals on plant growth. Auxin is the most abundant natural growth hormone, controlling apical dominance, tropism, elongation of shoots, and initiation of roots in plants. However, cadmium stress causes the degradation of indigenous auxin. To cope with this, auxin may be applied exogenously. To evaluate the role of auxin in cadmium -contaminated soil, different levels of the auxin precursor L-TRP were applied to plants growing in contaminated soil. Rice seedlings were dipped in a L-TRP solution for 2 h and transplanted into potted soil contaminated with 30 mg kg–1 cadmium. The results showed that the exogenous application of L-TRP improved the growth and yield of treated plants both in normal and contaminated soil. The data of different parameters showed that L-TRP enhanced plant height (), the number of tillers (), the number of panicles (), the 1000 grain weight (), and the paddy yield () in cadmiumcontaminated soil, as compared to plants
