Process for increasing plants resistance to an abiotic stress

A process for adapting plants to an abiotic stress, in particular to cold or to a hydric stress, in particular drought, humidity or salinity, wherein said process comprises at least a step of treatment of the plants by foliar field spraying with a composition comprising at least one xyloglucan derivative at a concentration of 0.01 mg to 2 g/ha of said xyloglucan derivative, advantageously from 0.1 mg to 0.5 g/ha, said spraying step being realized between 1 and 72 hours before the stress arrived, advantageously between 5 and 48 hours before said stress.