Comparative proteome analysis of drought-sensitive and drought-tolerant rapeseed roots and their hybrid Fl line under drought stress

摘要

Rapeseed (Brassica napus L.), which is the third leading source of vegetable oil, is sensitive to drought stress during the early vegetative growth stage. To investigate the initial response of rapeseed to drought stress, changes in the protein expression profiles of drought-sensitive (RGS-003) and drought-tolerant lines (SLM-003), and their Fl hybrid, were analyzed using a proteomics approach. Seven-day-old rapeseed seedlings were treated with drought stress by restricting water for 7 days, and proteins were extracted from roots and separated by two-dimensional polyacrylamide gel electrophoresis. In the sensitive rapeseed line, 35 protein spots were differentially expressed under drought stress, and proteins related to metabolism, energy, disease/defense, and transport were decreased. In the tolerant line, 32 protein spots were differentially expressed under drought stress, and proteins involved in metabolism, disease/defense, and transport were increased, while energy-related proteins were decreased. Six protein spots in Fl hybrid were common among expressed proteins in the drought-sensitive and -tolerant lines. Notably, tubulin beta-2 and heat shock protein 70 were decreased in the drought-sensitive line and hybrid Fl plants, while jasmonate-inducible protein and 20S protea-some subunit PAF1 were increased in the Fl hybrids and drought-tolerant line. These results indicate that (1) V-type H~+ ATPase, plasma-membrane associated cation-binding protein, HSP 90, and elongation factor EF-2 have a role in the drought tolerance of rapeseed; (2) The decreased levels of heat shock protein 70 and tubulin beta-2 in the drought-sensitive and hybrid Fl lines might explain the reduced growth of these lines in drought conditions.