The Effect of Plant Growth-Promoting Bacteria IB-22 on the Hydraulic Conductivity and Abundance of PIP2 Aquaporins in the Roots of an Abscisic Acid-Deficient Barley Mutant.

Little information is available on how rhizosphere bacteria affect abscisic acid (ABA) levels in plants and whether these bacterial effects are associated with improved plant water status. In this study, we tested the hypothesis that the stimulation of plant growth may be associated with the ability of ABA to increase the hydraulic conductivity of roots through the up-regulation of aquaporin. To do this, we studied the effect of bacteria capable of producing ABA on a barley mutant deficient in this hormone.

Influence of Plant Growth-Promoting Rhizobacteria on the Formation of Apoplastic Barriers and Uptake of Water and Potassium by Wheat Plants.

The formation of apoplastic barriers is important for controlling the uptake of water and ions by plants, thereby influencing plant growth. However, the effects of plant growth-promoting bacteria on the formation of apoplastic barriers, and the relationship between these effects and the ability of bacteria to influence the content of hormones in plants, have not been sufficiently studied. The content of cytokinins, auxins and potassium, characteristics of water relations, deposition of lignin and suberin and the formation of Casparian bands in the root endodermis of durum wheat ( Desf.

Effects of Phytohormone-Producing Rhizobacteria on Casparian Band Formation, Ion Homeostasis and Salt Tolerance of Durum Wheat.

Inoculation with plant growth-promoting rhizobacteria can increase plant salt resistance. We aimed to reveal bacterial effects on the formation of apoplastic barriers and hormone concentration in relation to maintaining ion homeostasis and growth of salt-stressed plants. The rhizosphere of a durum wheat variety was inoculated with cytokinin-producing and auxin-producing strains.

Growth-Promoting Effect of Rhizobacterium ( IB22) in Salt-Stressed Barley Depends on Abscisic Acid Accumulation in the Roots.

An ABA-deficient barley mutant (Az34) and its parental cultivar (Steptoe) were compared. Plants of salt-stressed Az34 (100 mmol m NaCl for 10 days) grown in sand were 40% smaller than those of "Steptoe", exhibited a lower leaf relative water content and lower ABA concentrations. Rhizosphere inoculation with IB22 increased plant growth of both genotypes.

Effects of Phosphate Shortage on Root Growth and Hormone Content of Barley Depend on Capacity of the Roots to Accumulate ABA.

Although changes in root architecture in response to the environment can optimize mineral and water nutrient uptake, mechanisms regulating these changes are not well-understood. We investigated whether P deprivation effects on root development are mediated by abscisic acid (ABA) and its interactions with other hormones. The ABA-deficient barley mutant and its wild-type (WT) were grown in P-deprived and P-replete conditions, and hormones were measured in whole roots and root tips.

Rhizobacteria Inoculation Effects on Phytohormone Status of Potato Microclones Cultivated In Vitro under Osmotic Stress.

Water deficits inhibit plant growth and decrease crop productivity. Remedies are needed to counter this increasingly urgent problem in practical farming. One possible approach is to utilize rhizobacteria known to increase plant resistance to abiotic and other stresses.