Pulsatory growth of pollen tubes: investigation of a possible relationship with the periodic distribution of cell wall components

Time-lapse video microscopy has revealed that pollen tubes may show pulsatory growth and transient irregularities in the shape of their tip. The question has been addressed whether the earlier reported periodic, band-like distribution of certain cell wall components could be correlated to fluctuations in the growth rate. Pollen tubes of Nicotiana tabacum, Petunia hybrida and Gasteria verrucosa, known to show regular bands in their cell wall, displayed pulsatory growth, whereas pollen tubes of Campanula sarmatica and Lilium longiflorum, which have a rather homogeneous cell wall pattern, showed a steady growth. These findings are consistent with the hypothesis that pulsatory growth and band-like cell formation are coupled. However, the idea was not further supported by the observations made on Canna indica and Zea mays, which showed band-like distribution of pectin but a very steady growth.