At the end of kaliyuga ,The Lord will assume kalki avatar ,when adharma,would have grown out of proportion,with little or no value for morality. The Lord would then be born at chap pals in a poor family. He will come riding on a horse with a garland of tulsi around his neck and a sword in his hand to put an end to the evil deeds of Kalipurusha.When he appears in such form ,those using TULSI and worshipping it for its sanctity ,will be saved , according to the Puranas,