Role of Paclobutrazol on Root Stem and Leaf Inner Structure of Arabidopsis Thaliana L.0 Grown Under Different Light Intensities

Abstract

Light is one of the most important environmental factors affecting plant growth and development. Paclobutrazol (PBZ) is one of the members of Triazole compounds that possess the qualities of growth regulators. The study aimed to investigate the possible changes in anatomical structures of the root, stem, and leaf of A. tha liana grown under different light intensities and the role of pbz in these circumstances. The anatomical characteristics of the root, stem, and leaves of A. tha liana col.0 were measured after treating its seedlings at two weeks of age with Hock land's solution at different light intensities (3000, 6000, 9000, 12000 Lux) for four weeks. The results showed changes in anatomical characteristics due to light stress represented by a significant moral decrease in the diameter of the root, vascular cylinder, and thickness of the epidermis and cortex. It also led to a reduction in the width of the stem, the thickness of the xylem, and an increase in the thickness of the epidermis and phloem. Light stress caused a significant decrease in leaf thickness and the ratio of palisade tissue thickness to spongy tissue thickness. They addition the growth regulator PBZ causes a substantial increase in all of the anatomical characteristics of the stem, root, and leaves.