Solanum lycopersicum (tomato) pollen tubes as a cellular model to study polarized and oscillatory growth.

BARBERINI ML, MUSCHIETTI JP

San Miguel de Tucumán

Congreso; Sociedad Argentina de Investigación Bioquímica; 2009

Sociedad Argentina de Investigación Bioquímica

Growing pollen tubes provide an excellent single cell system to study the mechanistic of polarized and oscillatory growth. Here, we show experimental basis for using tomato as a working model to study pollen tube growth regulation through tomato pollen receptor kinase LePRK2. Wild type (WT) pollen tubes show a non-continuous growth rate typical of pollen tubes. We found that Ca2+ oscillates with the same period as growth but out of phase as indicated by Fluo-4 AM. To evaluate the participation of the actin cytoskeleton in pollen tube growth, we applied actin-cytoskeleton interfering agents. Promotion of actin depolymerization by 20 nM Latrunculin B (Lat B) resulted in an inhibition of pollen germination and a reduction in growth, abolishing the oscillatory growth behavior. Stabilization of microfilaments and actin-polymerization stimulation by 2 mM Jasplakinolide (Jas), caused depolarized growth in WT pollen tubes. Antisense-LePRK2 pollen tubes show abnormal growth maybe by an impairment in transduction through Ca2+-dependent pathways. In order to understand the role of LePRK2 in pollen tube, we will study its oscillatory tube growth compared to WT pollen. Oscillation and cytoskeleton studies in WT and these transgenic plants may constitute an appropriate tool to study the mechanisms that control pollen tube growth.