Sporophytic control of pollen tube growth and guidance in maize

摘要: Pollen tube germination, growth, and guidance (progamic phase) culminating in sperm discharge is a multi-stage process including complex interactions between the male gametophyte as well sporophytic tissues female (embryo sac), respectively. Inter- intra-specific crossing barriers maize Tripsacum have been studied precise description of progamic pollen development reported here. It was found that germination initial growth are rather unspecific, but an early, first barrier detected before arrival at transmitting tract. Pollination silks with incompatible pollination Ga1s/Ga1s-maize ga1-maize revealed another two incompatibility barriers, namely tract mistargeting insufficient support. Attraction support by seem to play key roles for growth. After leaving tracts, tubes navigate across ovule ovular cavity. embryo sac-less RNAi-line allowed role be determined maize. controlled restricted small region around micropyle, approximately 50‐100 mm diameter. This area comparable influence previously described ZmEA1-based short-range signalling. In conclusion, phase almost completely under control