Record ID No. |
2909 |
Author(s) |
Gamalero E., Berta G., Massa N., Glick B. R., Lingua G. , 2010 |
Affiliation |
Universita del Piemonte Orientale 'Amedeo Avogadro', Dipartimento di Scienze dell'Ambiente e della Vita, Viale Teresa Michel 11, 15121 Alessandria, Italy. graziella.berta@mfn.unipmn.it |
Title |
Interactions between Pseudomonas putida UW4 and Gigaspora rosea BEG9 and their consequences for the growth of cucumber under salt-stress conditions |
Source. Vol.(no):Page |
Journal of Applied Microbiology. 108(1): 236-245p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Soil plant relations |
Sub-subjects |
Difficult sites |
Host |
Cucumis sativus |
Organism |
Pseudomonas putida , Gigaspora rosea |
Country |
UK., Europe |
Abstracts |
Aims: After the determination of the toxic but nonlethal concentration of NaCl for cucumber, we examined the interaction between an ACC (1-aminocyclopropane-1-carboxylate) deaminase producing bacterial strain and an arbuscular mycorrhizal fungus (AMF) and their effects on cucumber growth under salinity. Methods and Results: In the first experiment, cucumber seedlings were exposed to 0.1, 50, 100 or 200 mmol l-1 NaCl, and plant biomass and leaf area were measured. While seeds exposed to 200 mmol l-1 NaCl did not germinate, plant growth and leaf size were reduced by 50 or 100 mmol l-1 salt. The latter salt concentration caused plant death in 1 month. In the second experiment, seeds were inoculated with the ACC deaminase-producing strain Pseudomonas putida UW4 (AcdS+), its mutant unable to produce the enzyme (AcdS-), or the AMF Gigaspora rosea BEG9, individually or in combination and exposed to 75 mmol l-1 salt. Plant morphometric and root architectural parameters, mycorrhizal and bacterial colonization and the influence of each micro-organism on the photosynthetic efficiency were evaluated. The AcdS+ strain or the AMF, inoculated alone, increased plant growth, affected root architecture and improved photosynthetic activity. Mycorrhizal colonization was inhibited by each bacterial strain. Conclusions: Salinity negatively affects cucumber growth and health, but root colonization by ACC deaminase-producing bacteria or arbuscular mycorrhizal fungi can improve plant tolerance to such stressful condition. Significance and Impact of the Study: Arbuscular mycorrhizal fungus and bacterial ACC deaminase may ameliorate plant growth under stressful conditions. It was previously shown that, under optimal growth conditions, Ps. putida UW4 AcdS+ increases root colonization by Gi. rosea resulting in synergistic effects on cucumber growth. These results suggest that while in optimal conditions ACC deaminase is mainly involved in the bacteria/fungus interactions, while under stressful conditions this enzyme plays a role in plant/bacterium interactions. This finding is relevant from an ecological and an applicative point of view. |