Oil body membrane proteins as sensors of salt stress in sunflower seedlings: a proteomic insight

Sunflower, an important oil-yielding crop of tremendous economic importance worldwide, is sensitive to salt stress like many other agriculturally important crops. Different varieties of sunflower exhibit notable variations in their sensitivity/tolerance to salt-stress. Sensing of salt stress in sunflower is evident as early as at the seedling stage. Oil bodies, the major storehouse of fatty acids, are encased in a phospholipid monolayer containing intrinsic and extrinsic proteins. Any changes expected in the fatty acid composition of oil bodies as a response to salt stress are first perceived through alterations in the expression of oil body membrane proteins (OBMPs). The present investigations provide an in-depth proteomic analysis of OBMPs in the seedling cotyledons of three sunflower varieties exhibiting variations in their salt sensitivity. The exhaustive data from the LC‒MS/MS analysis of OBMPs highlight the differences in the levels of expression of a number of intrinsic and transiently expressed protein constituents of oil body membranes. The present proteomic analysis, thus, provides an insight into proteins capable of sensing salt stress as an early signaling response in sunflower seedlings.