The ultrastructural response of root cells to stressful conditions

• Published in: Environmental and experimental botany 1993, Vol.33 (1), p.11-26
• Main Authors: CIAMPOROVA, M, MISTRIK, I
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Plants and fungi
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/0098-8472(93)90052-H

Changes in the ultrastructure of root cells of Zea mays under non-lethal drought, salt, low and high temperature stresses, and of root cells of Valerianella locusta at freezing temperatures were investigated. The structural responses of cells of the same type and age, i.e. epidermis and cortex at 1.5 mm from the apex, were examined with the aim of comparing the specificity of stress effect in terms of cellular responses. Nuclei had condensed (in drought) or decondensed chromatin and highly sensitive nucleoli (in the cold, heat). ER became arranged into parallel complexes with drought and in the cold. The Golgi apparatus disintegrated only under water deficit. Mitochondrial internal structure was the most variable. However, the number of mitochondrial cristae was reduced by all types of stress indicating that reduction in energy production might contribute to the decreased growth which generally accompanies stress conditions. The reactions of ER and polyribosomes may be related to the induction of stress protein synthesis in root cells which occurs with all kinds of stresses. There is no one structural response which is unique to root cells, nor is the response of root cells uniform. The reason for such complex relationships may be that the primary effect of a stress is on cell membranes and possibly also on cell cytoskeleton or nucleus which then induced secondary or tertiary effects with similar or different structural manifestations.