Response to saline stress and aquaporin expression in Azospirillum-inoculated barley seedlings

ZAWOZNIK M.; AMENEIROS M.; BENAVIDES P.; VAZQUEZ SC; GROPPA MD

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

SPRINGER

Año: 2011 vol. 90 p. 1389 - 1397

0175-7598

The ability of two strains of Azospirillum brasilenseto mitigate NaCl stress in barley plants was evaluated.Barley seedlings were inoculated and subjected to 200 mMNaCl for 18 days. Several days after NaCl treatment, asignificant decline in biomass as well as in height wasobserved in uninoculated plants. However, smaller reductionsin biomass and height were detected in plantsinoculated with strain Az39. All the stressed plants showedsignificantly higher Na+ but lower K+ contents in theirshoots. The growth rate of uninoculated plants was adverselyaffected by saline treatment, which was associated with higherputrescine content and lower levels of HvPIP2;1 transcripts inthe roots. Azospirillum inoculation triggered the transcriptionof this gene. Our results suggest that barley plants inoculatedwith A. brasilense may be better prepared to thrive undersaline conditions. To our knowledge, this is the first reportshowing an effect of Azospirillum inoculation on theexpression of PIP2;1, a gene involved in the synthesis ofroot water channels.