摘要
In contrast to higher animals,plants maintain the capacity of generating new organs throughout their lifespan.Stem cells in shoot meristem provide the source of all above-ground organs.\nArabidopsis,shoot stem cell homeostasis is maintained by homeodomain(HD)transcription factors in two main regulatory pathways.The WUSCHEL(WUS)gene is transcribed in the organizing center(OC)below the stem cells.WUS protein moves into the stem cells where it directly activates CLAVATA3(CLV3)expression and thus specifies the stem cell identity.SHOOTMERISTEMLESS(STM)is expressed throughout the shoot meristem and represses stem cell differentiation(Aichinger et al.,2012)(Figure 1A).Whether and how these two pathways interact to regulate shoot stem cell homeostasis were not clear until now.
