Oral Presentation International Plant Molecular Biology Conference 2024

Signaling Processes in Plant Reproduction (#398)

Ueli Grossniklaus 1 , Nicholas Desnoyer 1 , Andrea Zupunski 1 , Stefano Bencivenga 1 , Martin A Mecchia 1 , Alejandro Giraldo-Fonseca 1
  1. University of Zürich, Zurich, Switzerland

Research in our laboratory focuses on the developmental genetics of plant reproduction, with an emphasis on cell-cell communication during double fertilization. Fertilization depends on the proper reception of the pollen tube by the synergid cells involving a complex interplay mediated by calcium signaling [1]. We have shown that receptor kinases of the CrRLK1L subfamily play an important role in reproduction, with the FERONIA (FER) receptor kinase acting in the synergids and the two redundant ANXUR (ANX1/2) receptor kinases in the pollen tube [2,3]. Since its discovery as a key player in plant reproduction, FER has been shown to play a role in a multitude of physiological and developmental processes, including cell expansion, hormone signaling, and innate immunity. The extracellular domain of CrRLK1Ls has similarities with malectin and can bind to pectin, but it was also reported to bind secreted peptides of the RAPID ALKALINIZATION FACTOR (RALF) and the POLLEN COAT PROTEIN B-class peptides (PCP-B) families [4-7]. Thus, the functions of CrRLK1Ls are diverse and complex. Using the evolutionary distant models Arabidopsis thaliana and Marchantia polymorpha, we aim at deciphering the mechanisms underlying this important, plant-specific signaling pathway. We will report on our recent advances in identifying downstream signaling components and in characterizing interactions between related pathways.

  1. Ngo QA, Vogler H, Lituiev DS, Nestorova A, Grossniklaus U (2014). A calcium dialog mediated by FERONIA signal transduction controls plant sperm delivery. Dev Cell 29, 491-500.
  2. Escobar-Restrepo JM, Huck N, Kessler S, Gagliardini V, Gheyselinck J, Yang WC, Grossniklaus U (2007). The FERONIA receptor-like kinase mediates male-female interactions during pollen tube reception. Science 317:656-660.
  3. Boisson-Dernier AJ, Roy S, Kritsas K, Grobei MS, Jaciubek M, Schroeder JI, Grossniklaus U (2009). Disruption of the pollen-expressed FERONIA homologs ANXUR1 and ANXUR2 triggers pollen tube discharge. Development 136, 3279-3288.
  4. Haruta M, Sabat G, Stecker K, Minkoff BB, Sussman MR (2014). A peptide homone and its receptor protein kinase regulate plant cell expansion. Science 343, 408-411.
  5. Mecchia M, Santos-Fernandez G, Duss NN, Somoza SC, Boisson-Dernier A, Gagliardini V, Martínez-Bernardini A, Ndinyanka Fabrice T, Ringli C, Muschietti JP, Grossniklaus U (2017) RALF4/19 peptides interact with LRX proteins to control pollen tube growth in Arabidopsis. Science 358, 1600-1603.
  6. Moussu S, Broyart C, Santos-Fernandez G, Augustin S, Wehrle S, Grossniklaus U, Santiago J (2020) Structural basis for recognition of RALF peptides by LRX proteins during pollen tube growth. Proc Natl Acad Sci USA 117, 7494-7503.
  7. Liu C, Shen L, Xiao Y, Vyshedsky D, Peng C, Sun X, Liu Z, Cheng L, Zhang H, Han Z, Chai J, Wu HM, Cheung AY, Li C (2021). Pollen PCP-B peptides unlock a stigma peptide-receptor kinase gating mechanism for pollination. Science 372, 171-175.