Modulation of endogenous indole-3-acetic acid biosynthesis in bacteroids within Medicago sativa nodules.

To evaluate the dose-response effects of endogenous indole-3-acetic acid (IAA) on Medicago plant growth and dry weight production, we increased the synthesis of IAA in both free-living and symbiosis-stage rhizobial bacteroids during Rhizobium-legume symbiosis. For this purpose, site-directed mutagenesis was applied to modify an 85-bp promoter sequence, driving the expression of iaaM and tms2 genes for IAA biosynthesis. A positive correlation was found between the higher expression of IAA biosynthetic genes in free-living bacteria and the increased production of IAA under both free-living and symbiotic conditions.

Development of novel pea protein-based nanoemulsions for delivery of nutraceuticals.

A novel pea protein-based emulsifier was used in the production of oil in water (O/W) nanoemulsions. The regions of kinetically stabilized O/W emulsions were individuated in a pseudoternary diagram containing different pea protein, sunflower oil, and water fractions. The stable O/W emulsion region was widened by the addition of NaCl to the aqueous phase or, to a more significant extent, by high pressure homogenization (HPH) processing.

Introduction of a novel pathway for IAA biosynthesis to rhizobia alters vetch root nodule development.

We introduced into Rhizobium leguminosarum bv. viciae LPR1105 a new pathway for the biosynthesis of the auxin, indole-3-acetic acid (IAA), under the control of a stationary phase-activated promoter active both in free-living bacteria and bacteroids. The newly introduced genes are the iaaM gene from Pseudomonas savastanoi and the tms2 gene from Agrobacterium tumefaciens.

Indole-3-acetic acid regulates the central metabolic pathways in Escherichia coli.

The physiological changes induced by indoleacetic acid (IAA) treatment were investigated in the totally sequenced Escherichia coli K-12 MG1655. DNA macroarrays were used to measure the mRNA levels for all the 4290 E. coli protein-coding genes; 50 genes (1.

Indole-3-acetic acid improves Escherichia coli's defences to stress.

Indole-3-acetic acid (IAA) is a ubiquitous molecule playing regulatory roles in many living organisms. To elucidate the physiological changes induced by IAA treatment, we used Escherichia coli K-12 as a model system. By microarray analysis we found that 16 genes showed an altered expression level in IAA-treated cells.

Characterisation of Phaseolus symbionts isolated from Mediterranean soils and analysis of genetic factors related to pH tolerance.

The ultimate objective of PhIMED, in which two European (Germany, Italy) and two Mediterranean (Morocco, Egypt) countries collaborate, is to improve the cultivation of French bean (Phaseolus vulgaris) under arid and semi-arid conditions by analysing and enhancing stress tolerance of the nitrogen fixing rhizobial microsymbionts. Rhizobial strains nodulating P. vulgaris (RP strains) isolated from areas in Morocco frequently subjected to drought were analysed for their salt and pH tolerance and their phylogenetic relationship.

A variety of RNA polymerases II and III-dependent promoter classes is repressed by factors containing the Krüppel-associated/finger preceding box of zinc finger proteins.

KRAB/FPB (Krüppel-associated/finger preceding box) domains are small, portable transcriptional repression motifs, encoded by hundreds of vertebrates C2-H2-type zinc finger genes. We report that KRAB/FPB domains feature an unprecedented, highly promiscuous DNA-binding dependent transcriptional repressing activity. Indeed, template bound chimeric factors containing KRAB/FPB modules actively repress in vivo the transcription of distinct promoter classes that depend on different core elements, recruit distinct basal transcriptional apparatuses and are transcribed either by RNA polymerase II or III.