Microinjection of Guanine NucleotideAnalogues into Lily Pollen Tubes Results in Isodiametric TipExpansion

Abstract

Heterotrimeric and small G-proteins aresupposed to participate in tip growth of plant cells. Quantitative changes intip growth rate after introduction of non-hydrolysable guanine nucleotideanalogues (NA) into lily pollen tubes have been interpreted as support for thehypothesis that heterotrimeric G-proteins regulate tube elongation (Ma et al.,1999[11]). Here, we report that microinjection of guanineNA into lily pollen tubes causes loss of growth polarity, resulting inisodiametric tip swelling. Our results are compatible with current modelssuggesting an involvement of plant Rho-related small G-proteins (Rop) in themaintenance of pollen tube polarity and in tip morphogenesis.

Abbreviations

ADP-β-S: adenosine5′-O-(2-thiodiphosphate)

ATP-γ-S: adenosine5′-O-(3-thiotriphosphate)

GDP-β-S: guanosine5′-O-(2-thiodiphosphate)

GTP-γ-S: guanosine5′-O-(3-thiotriphosphate)

NA: nucleotideanalogues

Key words

Tip growth - Liliumlongiflorum - microinjection - pollentube - G-proteins - cell polarity

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Section Editor: A. M. C. Emons