P. putida UW4 significantly released the inhibition of hypoxic stresses on cucumber plants biomass. The protein profiles of the roots of cucumber seedlings in response to the plantgrowth-
promoting bacterium P. putida UW4 and hypoxia have suggested how the protein and metabolism pathways are regulated. Fig. 5 shows a model of this PGPB and the hypoxic stress response. P. putida UW4 and hypoxic stress stimulated gene expression, the mRNA was processed and translated, the proteins involved in carbohydrate metabolism, nitrogen metabolism, defense stress, antioxidant, binding and others were induced, these proteins might be work cooperatively to
resist stress and keep plant growth on a more or less even keel. This study also provided strategies to identify enzymes potentially involved in the interaction between plants and
PGPB and to develop a better understanding of the overall response of plants to PGPB in hypoxic conditions.