The 30th International Conference on Arabidopsis Research (ICAR 2019)

482 / 2019-02-28 03:10:28

Functional Analysis of WIP-mediated Repression of Organ Growth

WIP, melon, flower, carpel, sex determination

Growth and Development > Growth and Development

Although most angiosperms develop hermaphrodite flowers, 10% of the species process different sexual morphs with male and female flowers on the same plant or with separate male and female plants. Sex determination is a process that leads to the physical separation of male (stamens) and female (carpels) reproductive organs on different flowers or individual plants. In Cucumis melo (melon), floral primordia are initially bisexual with the sex determination occurring by the selective developmental arrest of either the stamen or the carpel primordia, resulting in unisexual flowers. The expression of CmWIP1, encodes a zinc finger transcription factor, in melon carpel primordia inhibits their further development, leading to the formation of male flowers. To unravel the genetic networks of CmWIP1-mediated repression of carpel development, we exploited the model species Arabidopsis. The growth of Arabidopsis plants and carpels is inhibited by the over-expression of either CmWIP1 or Arabidopsis WIP homologues (AtWIPs) and the ectopic induction of AtWIPs in the carpel primordia respectively, suggesting that AtWIPs are functionally conserved with CmWIP1 in arresting plant/organ growth. Based on this, we used a dexamethasone (DEX) inducible system to over-express AtWIPs, and carried RNA-Seq, ChIP-Seq and EMS mutagenesis to find possible regulators that are involved in WIP-mediated organ development in Arabidopsis and eventually sex determination in melon.