Lauter Nick, Kampani Archana, Carlson Shawn, Goebel Mark, Moose Stephen P
Department of Crop Sciences, University of Illinois, 1201 West Gregory Drive, Urbana, IL 61801, USA.
Proc Natl Acad Sci U S A. 2005 Jun 28;102(26):9412-7. doi: 10.1073/pnas.0503927102. Epub 2005 Jun 15.
Shoot development in many higher plant species is characterized by phase change, where meristems and organs transition from one set of identities to another. The transition from a juvenile to adult leaf identity in maize is regulated by the APETALA2-like gene glossy15 (gl15). We demonstrate here that increasing gl15 activity in transgenic maize not only increases the number of leaves expressing juvenile traits, but also delays the onset of reproductive development, indicating that gl15 plays a primary role in the maintenance of the juvenile phase. We also show that the accumulation of a maize microRNA homologous to miR172 increases during shoot development and mediates gl15 mRNA degradation. These data indicate that vegetative phase change in maize is regulated by the opposing actions of gl15 and miR172, with gl15 maintaining the juvenile phase and miR172 promoting the transition to the adult phase by down-regulation of gl15. Our results also suggest that the balance of activities between APETALA2-like genes and miR172 may be a general mechanism for regulating vegetative phase change in higher plants.
许多高等植物物种的茎尖发育具有阶段变化的特征，即分生组织和器官从一种身份状态转变为另一种身份状态。玉米中从幼叶身份向成熟叶身份的转变受APETALA2类基因glossy15（gl15）调控。我们在此证明，在转基因玉米中增加gl15的活性不仅会增加表达幼叶性状的叶片数量，还会延迟生殖发育的开始，这表明gl15在幼年期的维持中起主要作用。我们还表明，与miR17
2同源的一种玉米微小RNA在茎尖发育过程中积累，并介导gl15 mRNA的降解。这些数据表明，玉米的营养阶段变化受gl15和miR172的相反作用调控，gl15维持幼年期，而miR172通过下调gl15促进向成年期的转变。我们的结果还表明，APETALA2类基因和miR172之间的活性平衡可能是调控高等植物营养阶段变化的普遍机制。
