Rate of seed imbibition and initiation of germination varies considerably with available water supply. Variation in germination determines seedling development and consequently uniformity of early crop establishment. This feature can strongly influence productivity of chickpea under dryland environments. Using a specific controlled environments potting system, variable soil water contents were simulated to compare germination five genotypes with equivalent seed size. To reveal the potential mechanism for differences in germination rate among tolerant (Rupali) and sensitive (KJ850) genotypes, a comprehensive proteomics approach was applied to identify water deficit responsive proteins. The results of 2D gel statistical analysis (P≤0.05) done by PDQuest and subsequent MALDI-TOF/TOF mass spectrometry revealed differential expression of a number of potentially important stress-related and novel proteins in the genotype with rapid germination. In addition, we found distinctly different dynamic patterns of storage proteins expression among genotypes, reflecting diverse post-translational modifications and variation in their mobilization. This study demonstrates that the rapid germination trait under severely limited water supply is associated with coordinated expression of proteins involved in cellular functions such as signal transduction, specific metabolism, cell defense and protection. The data will provide the basis for an understanding of the likely molecular mechanisms that permit more rapid germination of chickpea in soils where water supply is strictly limited.

Keywords