Regulation of plant development in Arabidopsis

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The development of a complex organism, such as a plant, requires the function of multiple pathways that regulate various aspects of the developmental process. Here pathways that regulate various aspects of plant development are investigated. A regulatory module consisting of a NAC-domain transcription factor, CUC2, in which targeting by the miRNA family, miRNA164, is disrupted, was investigated. This disruption resulted in an overaccumulation of the CUC2 transcript. This disruption uncovers roles for this regulatory module in controlling lateral organ enlargement and patterning. This regulatory module is proposed to act as a global regulator of lateral organ patterning and enlargement as well as meristem maintenance. A novel function for a Mitogen-Activated Protein Kinase (MAPK) cascade in floral organ abscission is uncovered. Many plants use abscission as a means to shed unwanted organs or to release fruit and seeds at maturity. This process requires tight coordination through regulatory pathways, including the MKK4/MKK5 MAPK cascade. The DEVIL (DVL) family encodes predicted small proteins that all carry a conserved C-terminal motif. While it remains unclear if these small proteins play a role in signaling pathways, several other small protein families in plants have been shown to play such a role. Here investigations into the active gene product and possible genetic interactors are discussed.