PHOSPHOROUS MOVILIZATION IN
STRAWBERRY PLANTS BY A STRAIN OF
MESORHIZOBIUM MEDITERRANEUM
WHICH NODULATES CICER ARIETINUM
Alvaro Peix1, Laura Martín-Martín1, Eustoquio Martínez-Molina1, Pedro F.
Mateos1, Claudino Rodríguez-Barrueco2, Encarna Velázquez1
Departamento de Microbiología y Genética. Universidad de Salamanca
Phosphorous is, after nitrogen, the second
most important element in plant nutrition
In many plants of agronomic interest,
phosphorous is a key a key factor in fruit
properties and precocity, which is very
important under a commercial point of view
only 0.1% of the total phosphorous from
soil is available to plants
Among Plant Growth-Promoting Rhizobacteria,
there are some strains which mode of action is
based on solubilization of insoluble phosphates
and mobilization of P in soil-plant interface
Among Phosphate Solubilizing Bacteria, the most
powerful strains are included in diverse taxonomic
groups,
as
Gram
negative
Proteobacteria
(pseudomonads and rhizobia) and Gram positive
bacteria of low G+C content (Bacillus).
Some strains of rhizobia and other related
genera, besides their potential to nodulate
legumes and fix atmospheric nitrogen, can
solubilize phosphates and mobilize P to plants
The strain PECA21 is able to nodulate, fix nitrogen and
movilize phosphorous to Cicer arietinum
Phosphate solubilization halos of strain
PECA21 grown in YED+ 0.3% tricalcium
phosphate medium
Identification
Stable Low Molecular Weight (LMW) RNA profiles obtained
by Staircase Electrophoresis
LMW RNA profiles
LMW
RNA
profiles
of
Mesorhizobium nodulating
PECA21:
type
Cicer
strains
from
arietinum and
Carril (1) M. ciceri USDA 3383T
Carril (2) M. mediterraneum USDA 3392T
Carril (3) PECA21
Phosphorous mobilization in strawberry plants
View of fruits
yielded by plants
from different
treatments
View of strawberry
plants growing in
growth chamber
Treatment
Dry weight
(g)
P (%)
N(%)
Production
(g/plant)
Controls
5.83a
0.195a
1.595a
8.927a
PECA21
5.46a
0.242a
1.625a
3.714a
PECA21-P
5.50a
0.309b
1.670a
18.046b
values followed by the same letter are not significantly different from each other at
p=0.05 according to Fisher's Protected LSD
Phosphorous mobilization in strawberry plants
Treatment
Dry
weight(g)
P (%)
N(%)
Production(
g/plant)
Control
5.83a
0.195a
1.595a
8.927a
PECA21
5.46a
0.242a
1.625a
3.714a
PECA21-P
5.50a
0.309b
1.670a
18.046b
values followed by the same letter are not significantly different from each
other at p=0.05 according to Fisher's Protected LSD
Bar charts of parameters measured in the experiment
PECA21-P
PECA21
CONTROL
0,309
PECA21-P
1,670
%P
0,242
1,625
0,195
1,595
PECA21
%N
CONTROL
18,046
5,50
producción
3,714
5,46
peso seco
8,927
5,83
CONCLUSIONS
LMW RNA profiles obtained by Staircase electrophoresis allow
the identification of phosphate solubilizing bacteria belonging to
very diverse taxonomic groups. In our case strain PECA21
isolated from chickpea was identified as Mesorhizobium
mediterraneum
In strawberry plants inoculated with strain Mesorhizobium
mediterraneum PECA21 added with phosphate, phosphorous
mobilization in plant-soil interface was observed, increasing
significantly their P content.
Strawberry plants inoculated with strain Mesorhizobium
mediterraneum PECA21 added with phosphate yielded fruit
production higher than twice the quantity compared to control
plants, and therefore this strains behaves as a good PGPR,
showing potential as microbial inoculant for strawberry in the
future.