Molecular mechanisms controlling plant organ abscission

抄録

Plants shed organs by abscission, removing leaves, flowers or fruits when the organs are senescent, damaged, diseased or mature. Abscission also affects agriculture; for example, abscission of fruits or cereal grains can significantly reduce crop yield. Abscission of organs typically occurs in a predetermined tissue region, the abscission zone (AZ). Organ abscission can be disturbed in two ways, inhibition of AZ differentiation in the organ or suppression of abscission processes in AZ cells. Recent studies, mainly in Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), and tomato (Solanum lycopersicum), have identified many genes involved in regulation of AZ differentiation and activation of abscission of flowers or floral organs, seeds, and fruits. In this review, we discuss the functions of these genes, the developmental regulation of AZ tissues, and the signaling pathways that induce abscission. We also discuss the emerging concept that the regulation of abscission involves many of the same regulators that function in determination of shoot apical meristem cell fate.