Signaling in pollination.

The past year has seen considerable advances in our understanding of signaling in pollen tubes. Evidence suggesting that lipids are involved in pollen tube guidance has opened up new avenues. Major advances have been made in understanding the roles of Rho-like GTPases and protein kinases in regulating pollen tube growth. Light is being shed on how signals may be integrated. It is becoming clear that the role of Ca(2+) in pollen tube growth is perhaps more complex than originally anticipated.