Some rhizobacteria contain the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase that degrades the ethylene precursor ACC and promotes plant growth, particularly under unfavorable environmental conditions. Pot experiments were performed to determine the effect of two ACC-utilizing strains Variovorax paradoxus 5C-2 and Achromobacter xylosoxidans Cm4 on vegetative growth, yield and water relations of potato cultivated with optimal and deficit irrigation. Generally, bacteria accelerated early vegetative development and plant flowering. Inoculation also increased tuber yield and number with the most pronounced growth-promoting effect apparent in deficit irrigated plants inoculated with A. xylosoxidans Cm4. Both strains improved water use efficiency independently of irrigation treatment. Generally, bacterial inoculation had limited impacts on leaf water relations as assessed by thermocouple psychrometry. Estimates of root bacterial colonization indicated that V. paradoxus 5C-2 actively colonised the plant roots under both watering regimes. Application of plant growth promoting rhizobacteria containing ACC deaminase offers promise for attenuating the growth inhibition of potatoes caused by water deficit.

crop yield, enzymes, flowering, inoculation, plant waterrelations, pot experimentation, potatoes, rhizosphere bacteria, stress,stress response, water stress, water use efficiency, Achromobacterxylosoxidans, Solanum tuberosum, Variovorax paradoxus, Achromobacter,Alcaligenaceae, Burkholderiales, Betaproteobacteria, Proteobacteria,Bacteria, prokaryotes, Solanum, Solanaceae, Solanales, dicotyledons,angiosperms, Spermatophyta, plants, eukaryotes, Variovorax,Comamonadaceae, 1-aminocyclopropane-1-carboxylate deaminase, anthesis,bacterium, Field Crops (FF005) (New March 2000), Plant Water Relations(FF062), Plant Production (FF100), Soil Biology (JJ100)

• Journal Article

• Drought