INVESTIGADORES
MUSCHIETTI jorge Prometeo
congresos y reuniones científicas
Título:
Molecular mechanisms of pollenpistil interactions in tomato and Arabidopsis plants
Autor/es:
MUSCHIETTI, JORGE; WENGIER, DIEGO; SOTO, GABRIELA; SALEM, TAMARA; BARBERINI, MARIA LAURA; MAZZELLA, AGUSTINA
Lugar:
Ciudad de Tucumán, Argentina
Reunión:
Conferencia; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009
Institución organizadora:
SAIB
Resumen:
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After
pollen grains germinate on the stigma,
pollen tubes elongate within the pistil to transport sperms to female
gametophytes for fertilization. During
pollination, pollen tubes perceive style signals triggering cytoplasmic events
required for tip growth.
We
characterized two pollen-specific receptor-like kinases, LePRK1 and LePRK2,
from tomato pollen involved in transducing style signals. We showed
over-expression of LePRK2-eGFP significantly decreased pollen tube length and
increased tube tip width, relative to eGFP tubes. Site-directed mutagenesis in two putative phosphorylation
motifs in the cytoplasmic juxtamembrane (JM) domain and overexpression in
tobacco pollen showed that both motifs have opposite effects in regulating
pollen tube length. We also used pollen tubes as a single cell system
to study the mechanistic of polarized and oscillatory growth. Tomato pollen
tubes showed a non-continuous growth rate and Ca2+ oscillated with
the same period but out of phase.
We
also study the participation of aquaporins mediating water and solutes
transport during pollen tube elongation. We found AtTIP5;1 and AtTIP1;3 are the
only aquaporins selectively and highly expressed in Arabidopsis thaliana pollen. They both showed urea and water
transport. We found that in tip1;3
and tip5;1 homozygous double mutant
plants, pollen tube length was significantly reduced under nitrogen starvation.