ISSN:
1432-2048
Keywords:
Key words:Nicotiana (pollen germination) – Phytosulfokine-α– Sulfated peptide – Peptide growth factor – Pollen germination – Pollen population effect
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. Density-dependent pollen germination and tube growth in vitro is a well-documented phenomenon, termed the pollen population effect, but far less is known about its molecular basis. We present evidence to support phytosulfokine-α [Y(SO3H)IY(SO3H)TQ; PSK-α] as a native bioactive factor contributing to this effect. Mature pollen grains of Nicotiana tabacum L. var.macrophylla were incubated in liquid medium for 2 h. Pollen germination frequency increased in a density-dependent manner from 625 to 46,000 grains/ml. Conditioned medium, obtained from the medium of pollen cultured at a density of 10,000 pollen grains/ml for 12 h, promoted the germination of pollen cultured at a low density (625 grains/ml). A rabbit antiserum against PSK-α specifically inhibited the promotive effect of conditioned medium. Quantification by enzyme-linked immunosorbent assay showed that the conditioned medium contained 0.4 nM of PSK-α. Exogenous PSK-α also stimulated pollen germination in the low-density culture. These results indicate that PSK-α is an important regulator involved in the pollen population effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250000370
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