Cyclic nucleotide-gated channel 18 is an essential Ca2+ channel in pollen tube tips for pollen tube guidance to ovules in Arabidopsis.
Gao QF, Gu LL, Wang HQ, Fei CF, Fang X, Hussain J, Sun SJ, Dong JY, Liu H, Wang YF. Proc Natl Acad Sci U S A. 2016 Mar 15; 113(11):3096-101. Epub 2016 Feb 29.