Novel functional roles for PERIANTHIA and SEUSS during floral organ identity specification, floral meristem termination, and gynoecial development

Abstract

The gynoecium is the female reproductive structure of angiosperm flowers. In Arabidopsis thaliana the gynoecium is composed of two carpels that are fused into a tube-like structure. As the gynoecial primordium arises from the floral meristem, a specialized meristematic structure, the carpel margin meristem (CMM), develops from portions of the medial gynoecial domain. The CMM is critical for reproductive competence because it gives rise to the ovules, the precursors of the seeds. Here we report a functional role for the transcription factor PERIANTHIA (PAN) in the development of the gynoecial medial domain and the formation of ovule primordia. This function of PAN is revealed in pan aintegumenta (ant) as well as seuss (seu) pan double mutants that form reduced numbers of ovules. Previously, PAN was identified as a regulator of perianth organ number and as a direct activator of AGAMOUS (AG) expression in floral whorl four. However, the seu pan double mutants display enhanced ectopic AG expression in developing sepals and the partial transformation of sepals to petals indicating a novel role for PAN in the repression of AG in floral whorl one. These results indicate that PAN functions as an activator or repressor of AG expression in a whorl-specific fashion. The seu pan double mutants also display enhanced floral indeterminacy, resulting in the formation of “fifth whorl” structures and disruption of WUSCHEL (WUS) expression patterns revealing a novel role for SEU in floral meristem termination.

Predicting gene regulatory networks by combining spatial and temporal gene expression data inArabidopsisroot stem cells

“…S6A). Since PAN was previously shown to be involved in a feed-forward loop with AGAMOUS (AG) and WUSCHEL (WUS) in the shoot apical meristem (35,36) we hypothesized that PAN could have a role in regulating the root stem cells.…”

“…Expression levels were calculated relative to UBQ10 (At4g05320) using the 2-ΔΔct method. Primers used were either previously published (36,52), or designed using Primer 3 Plus, and are listed in SI Appendix, Table S5.…”

Altered expression of the bZIP transcription factor DRINK ME affects growth and reproductive development in Arabidopsis thaliana

“…In plants, members of the basic‐leucine zipper (bZIP) family have been shown to play important roles in organ and tissue differentiation, photomorphogenesis, cell elongation, nitrogen/carbon balance control, energy metabolism, hormone and sugar signaling, flower maturation, seed development, and pathogen defense (Jakoby et al ., ; Cluis et al ., ; Guedes Corrêa et al ., ; Weltmeier et al ., ; Dietrich et al ., ; Alves et al ., ). In Arabidopsis, two bZIP genes have been reported to have a role in female reproductive development: UNFERTILIZED EMBRYO SAC 4 ( UNE4 ) (Pagnussat et al ., ) and PERIANTHIA ( PAN ) (Running and Meyerowitz, ; Wynn et al ., ), and one bZIP gene, bZIP34 , is involved in male reproductive development (Gibalová et al ., ).…”

Co-expression network analyses identify functional modules associated with development and stress response in Gossypium arboreum

“…In addition, the co-expression network shows that in the sub-network of Cotton_A_07061 ( REVOLUTA ), the positively co-expressed genes are generally highly expressed in vegetative tissues, whereas the negatively co-expressed genes are generally highly expressed in the reproductive tissues. For example, Cotton_A_07124, an orthologue of VND4 in Arabidopsis , is expressed in the developing xylem and regulates SCW growth14; whereas the MADS-box family Cotton_A_40148, the orthologue of AGAMOUS , is specifically expressed in mature parts such as the floral meristem, carpel and stamen15. The genes positively and negatively co-expressed with Cotton_A_28415 ( KNAT7 ) display the reverse tendency.…”