Early F-actin disorganization may be signaling vacuole disruption in incompatible pollen tubes of Nicotiana alata

ARIEL GOLDRAIJ; JUAN A ROLDÁN; HERNÁN ROJAS

Plant Signaling & Behaviour

Landes Biosciences

Lugar: Austin, TX; Año: 2012 vol. 7 p. 1 - 1

1559-2316

p style="margin: 0in; font-family: Calibri; font-size: 17pt;">Self-incompatibility (SI) systems appeared early in plant evolution as an effective mechanism to promote outcrossing and avoid inbreeding depression. These systems prevent self-fertilization by the recognition and rejection of self-pollen and pollen from closely related individuals. The most widespread SI system is based on the action of a pistil ribonuclease, the S-RNase, which recognizes and rejects incompatible pollen. S-RNases are endocyted by pollen tubes and stored into vacuoles. By a mechanism that is still unknown, these vacuoles are selectively disrupted in incompatible pollen, releasing S-RNases into the cytoplasm and allowing degradation of pollen RNA. Recently, we have studied the timing of in vivo alterations of pollen F-actin cytoskeleton after incompatible pollinations. Besides being essential for pollen growth, F-actin cytoskeleton is a very dynamic cellular component. Changes in  F-actin or