can the differences in the protein sequence be ranked according to their relevance to a certain stimuli, using a statistical method when the protein sequence is already available

Question

[lochanamp]

I'm trying to find the relevance of certain drought induced proteins in different plant families such as rice, sorghum and zea mays. since there could be many differences between the same protein in different families is there any statistical method where we can eliminate certain options(differences) and obtain the optimal result (a result of differences in proteins which attribute to drought stress well)?