ISHS Acta Horticulturae 280: I International Symposium on In Vitro Culture and Horticultural Breeding
CELLULAR MECHANISMS OF SALT AND WATER STRESS TOLERANCE IN PLANTS |
| Authors: | N. C. Carpita, Naim M. Iraki, N. K. Singh, Ray A. Bressan, Paul M. Hasegawa, M. Reuveni, M. Binzel, P. Christopher LaRosa, D. Nelson, R. Rietveld, Sherry R. Schnapp |
| DOI: | 10.17660/ActaHortic.1990.280.58 |
| Abstract:
We have investigated many of the underlying biochemical, physiological, and genetic determinants responsible for adaptation of plant cells to salt and desiccation stress. We have demonstrated that cell suspension cultures of tobacco (Nicotiana tabacum L. cv. W38) adapt osmotically to severe saline stress by absorbing considerable amounts of NaCl from the medium and by partitioning much of the salt in the vacuole. This partitioning function is accompanied both by changes in the degree to which NaCl is partitioned and in the ability of mitochondria to produce energy in the presence of high concentrations of NaCl. Cell volume in adapted cells is reduced to as little as 1/8 that of unadapted cells. Cells adapted to either NaCl or desiccation accumulate substantial amounts of sugars, proline, and other amino acids as additional osmolites, but do this at the expense of synthesis of cell wall polymers. This reduced cell volume which is associated with adaptation occurs despite maintenance of more than adequate turgor needed to drive cell expansion under normal conditions. We have deduced from our work that a lesion in xyloglucan metabolism is responsible for reduced cell expansion. We also uncovered several alterations in the expression of several vacuolar, cytoplasmic, and extracellular proteins by cells adapted to osmotic stress and are now characterizing their structural-functional relationships to the adaptation process. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
