Abstract:

In order to explore the relationship between proline metabolism and cold resistance, the study focused on determination of proline content, proline dehydrogenase activity, the expression of ProDH, and analysis of dynamic changes of these indexes. The results indicated that change of proline accumulation, to a certain extent, reflect the strength of cold resistance of tomato, for that free proline accumulation showed overall an increasing trend in chill-endurance O-33-1, and which was declined in cold-sensitive ‘Naiyun 2000’ under low temperature stress; It explained the accumulation of proline depends on a common regulation of P5CS and ProDH to maintain the proline content in plants at an appropriate level, that ProDH activity increased in the O-33-1, and discreased in ‘Naiyun 2000’. The relative expression of ProDH gene of two varieties was significantly decreased under low temperature stress. Therefore, the expression of the gene is inhibited under low temperature stress, so that the degradation of proline is regulated at the transcriptional level.