With the stress degree stronger and the stress time longer, the protein in xylemsap changed among 14.4~31KD for all alternative split-root osmotic stress.
Similar trend was showed with the xylemSAP ABA, but no difference was observed in xylem ABA in response to soil drying between different nitrogen treatments.
Roads, railways, water and gas mains, sewage pipes and electricity cables all move things around. So do the blood vessels of animals and the sap-carrying xylem and phloem of plants.