The proteome of the imbibition spillage in Cicer arietinum L.

Abstract

Being a preparative step for germination, seed imbibition is a hydration process that involves the release of seed molecules into the environment, an essential ecological aspect of this phase. On one side this leakage leads to unlocking the seed dormancy by removing abscisic acid and other pro-dormancy molecules, on the other side, it releases small molecules such as vitamins, amino acids, flavonoids, and proteins contributing to supporting germination by attracting symbionts, contrasting pathogens, and facilitating nutrients uptake. Here the proteome associated with the imbibition spillage of chickpea seeds emerges as a probe to understand the early events during germination and (pre-) symbiosis, providing a proxy to disclose the influence that the seed applies to the environment for optimal achievement of its eco-physiological needs. This proteome is clustered into two main groups that differ in chemical-physical properties and function. Most proteome entries belong to biochemical pathways that directly influence germination by enhancing nutrient uptake, protecting against stresses of various origins, and promoting symbiosis. A fraction of this proteome was found to be associated with accidental pathways due to the loss of proteins from teguments and fractured tissues. Here, germination, protection, and symbiosis emerge as a balanced proteomic triad aimed at enhancing and sustaining seedling emergence and plant growth.