Biochemical Changes of the Thai Glutinous Rice Cultivar MK1 in Response to Salinity Stress

Salinity constitutes one of the major abiotic constraints affecting rice productivity in many countries of the world. As salinity is known to interfere with physiological and biochemical processes, the present study was undertaken to assess the responses of physiological and biochemical characteristics of the Thai glutinous rice cultivar MK1 calli, subject to various concentrations of NaCl (0, 50, 100, 150, 200, 250, 300 and 350 mM). The changes in fresh weight, dry weight, survival percentage, proline content, total protein content, starch content, total soluble sugars and phenol content were investigated. When exposed to low salinity (50 mM NaCl), high survival percentage was observed. Fresh weight of calli was similar to non-saline control, whilst dry weight was slightly lower. Total protein content and starch content correlated with growth response. High salinity led to a significant increase in proline content, total soluble sugars and phenol content. Calli successfully developed into whole plantlets at salinities below 350 mM. The data reported herein suggest that salt-tolerant MK1 might be well adapted to areas of high (> 100 mM) salinity.