In the present study, the protective effect of nitric oxide (NO) against Cd-induced structural disturbances in pea (Pisum sativum) leaves was investigated. Cadmium treatment resulted in a decreased leaf size and thickness of the lamina, reduced intercellular spaces in the mesophyll, small pavement cells, and a high density of stomata. | Turkish Journal of Botany Turk J Bot (2013) 37: 698-707 © TÜBİTAK doi: Research Article Cadmium-induced structural disturbances in Pisum sativum leaves are alleviated by nitric oxide 1 2 3 1, Tuan Anh TRAN , Valya VASSILEVA , Petar PETROV , Losanka Petrova POPOVA * Department of Photosynthesis, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria 2 Department of Plant Stress Molecular Biology, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria 3 Department of Mineral Nutrition and Water Relations, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria 1 Received: Accepted: Published Online: Printed: Abstract: In the present study, the protective effect of nitric oxide (NO) against Cd-induced structural disturbances in pea (Pisum sativum) leaves was investigated. Cadmium treatment resulted in a decreased leaf size and thickness of the lamina, reduced intercellular spaces in the mesophyll, small pavement cells, and a high density of stomata. These abnormalities were partially or fully reversed by a simultaneous application of Cd and the NO donor, sodium nitroprusside (SNP). The concentration of 1000 µM SNP was very effective in counteracting the adverse effects of Cd and resulted in leaf structural parameters close to those of the control leaves. These findings suggest that exogenous NO can effectively facilitate structural adjustments in pea leaves under Cd stress, which could improve stress tolerance at the whole-plant level. Key words: Cadmium, leaves, guard cells, nitric oxide, pavement cells, Pisum sativum 1. Introduction Cadmium (Cd) is a highly toxic trace element, which enters the environment mainly from industrial processes and phosphate fertilisers. It can reach high levels in agricultural soils and is easily assimilated by plants.
