It seems that different plant growth-promoting bacteria affect plants differently under (salt) stress conditions. Rhizospheric binding bacteria (such as P. putida UW4) allow the salt to accumulate and presumably partition into the vacuole (away from the cytosolic metabolism so that it cannot affect plant growth) but facilitate plant growth by keeping the stress ethylene level low with ACC deaminase activity. On the otherhand, plant growth-promoting bacterial endophytes limit the concentration of sodium in plant shoots