@unpublished{21994,
  abstract     = {Adaptive plant development is orchestrated, among others, by directional, intercellular transport of the phytohormone auxin. Self-organizing development, such as flexible vasculature formation, depends on so-called auxin canalization, manifested by the gradual formation of auxin transport channels through feedback between auxin signalling and transport. Herein, we identify MAKR6 as an important, novel component in this feedback. MAKR6 expression accumulates strongly in vascular cells and is tightly regulated by auxin via the Aux/IAA-ARF-WRKY23 transcriptional network. MAKR6 is required for auxin canalization-dependent processes, including leaf venation, vasculature regeneration, and de novo auxin channel formation from local auxin sources. Mechanistically, MAKR6 interacts with the PIN1 auxin transporter, modulating its trafficking and polarization. MAKR6 also associates with and integrates two key receptor-like kinase complexes involved in canalization, TMK1/4 and the CAMEL-CANAR. Together, our study establishes MAKR6 as a multifaceted regulator that couples transcriptional auxin signalling to PIN1 repolarization and coordinates multiple RLK-mediated signalling pathways during canalization. This provides mechanistic insights into auxin canalization and exemplifies a framework for exploring similar regulatory nodes in other developmental contexts.},
  author       = {Ge, Zengxiang and Koczka, Lilla and Mazur, Ewa and Molnar, Gergely and Vladimirtsev, Dmitrii and Kassem, Nada and Ait Ikene, Sara and Fiedler, Lukas and Friml, Jiří},
  booktitle    = {bioRxiv},
  title        = {{MAKR6 integrates TMK and CAMEL/CANAR signalling for auxin canalization in Arabidopsis}},
  doi          = {10.1101/2025.10.07.680881},
  year         = {2026},
}

@article{14726,
  abstract     = {Autocrine signaling pathways regulated by RAPID ALKALINIZATION FACTORs (RALFs) control cell wall integrity during pollen tube germination and growth in Arabidopsis (Arabidopsis thaliana). To investigate the role of pollen-specific RALFs in another plant species, we combined gene expression data with phylogenetic and biochemical studies to identify candidate orthologs in maize (Zea mays). We show that Clade IB ZmRALF2/3 mutations, but not Clade III ZmRALF1/5 mutations, cause cell wall instability in the sub-apical region of the growing pollen tube. ZmRALF2/3 are mainly located in the cell wall and are partially able to complement the pollen germination defect of their Arabidopsis orthologs AtRALF4/19. Mutations in ZmRALF2/3 compromise pectin distribution patterns leading to altered cell wall organization and thickness culminating in pollen tube burst. Clade IB, but not Clade III ZmRALFs, strongly interact as ligands with the pollen-specific Catharanthus roseus RLK1-like (CrRLK1L) receptor kinases Zea mays FERONIA-like (ZmFERL) 4/7/9, LORELEI-like glycosylphosphatidylinositol-anchor (LLG) proteins Zea mays LLG 1 and 2 (ZmLLG1/2) and Zea mays pollen extension-like (PEX) cell wall proteins ZmPEX2/4. Notably, ZmFERL4 outcompetes ZmLLG2 and ZmPEX2 outcompetes ZmFERL4 for ZmRALF2 binding. Based on these data, we suggest that Clade IB RALFs act in a dual role as cell wall components and extracellular sensors to regulate cell wall integrity and thickness during pollen tube growth in maize and probably other plants.},
  author       = {Zhou, Liang-Zi and Wang, Lele and Chen, Xia and Ge, Zengxiang and Mergner, Julia and Li, Xingli and Küster, Bernhard and Längst, Gernot and Qu, Li-Jia and Dresselhaus, Thomas},
  issn         = {1532-298X},
  journal      = {The Plant Cell},
  keywords     = {Cell Biology, Plant Science},
  number       = {5},
  publisher    = {Oxford University Press},
  title        = {{The RALF signaling pathway regulates cell wall integrity during pollen tube growth in maize}},
  doi          = {10.1093/plcell/koad324},
  volume       = {36},
  year         = {2024},
}

@article{18596,
  abstract     = {Hormone perception and signaling pathways have a fundamental regulatory function in the physiological processes of plants. Cytokinins, a class of plant hormones, regulate cell division and meristem maintenance. The cytokinin signaling pathway is well established in the model plant Arabidopsis thaliana. Several negative feedback mechanisms, tightly controlling cytokinin signaling output, have been described previously. In this study, we identified a new feedback mechanism executed through alternative splicing of the cytokinin receptor AHK4/CRE1. A novel splicing variant named CRE1int7 results from seventh intron retention, introducing a premature termination codon in the transcript. We showed that CRE1int7 is translated in planta into a truncated receptor lacking the C-terminal receiver domain essential for signal transduction. CRE1int7 can bind cytokinin but cannot activate the downstream cascade. We present a novel negative feedback mechanism of the cytokinin signaling pathway, facilitated by a decoy receptor that can inactivate canonical cytokinin receptors via dimerization and compete with them for ligand binding. Ensuring proper plant growth and development requires precise control of the cytokinin signaling pathway at several levels. CRE1int7 represents a so-far unknown mechanism for fine-tuning the cytokinin signaling pathway in Arabidopsis.},
  author       = {Králová, Michaela and Kubalová, Ivona and Hajný, Jakub and Kubiasova, Karolina and Vagaská, Karolína and Ge, Zengxiang and Gallei, Michelle C and Semerádová, Hana and Kuchařová, Anna and Hönig, Martin and Monzer, Aline and Kovačik, Martin and Friml, Jiří and Novák, Ondřej and Benková, Eva and Ikeda, Yoshihisa and Zalabák, David},
  issn         = {1674-2052},
  journal      = {Molecular Plant},
  number       = {12},
  pages        = {1850--1865},
  publisher    = {Elsevier},
  title        = {{A decoy receptor derived from alternative splicing fine-tunes cytokinin signaling in Arabidopsis}},
  doi          = {10.1016/j.molp.2024.11.001},
  volume       = {17},
  year         = {2024},
}

@article{17069,
  abstract     = {Fertilization of an egg by multiple sperm (polyspermy) leads to lethal genome imbalance and chromosome segregation defects. In Arabidopsis thaliana, the block to polyspermy is facilitated by a mechanism that prevents polytubey (the arrival of multiple pollen tubes to one ovule). We show here that FERONIA, ANJEA, and HERCULES RECEPTOR KINASE 1 receptor-like kinases located at the septum interact with pollen tube–specific RALF6, 7, 16, 36, and 37 peptide ligands to establish this polytubey block. The same combination of RALF (rapid alkalinization factor) peptides and receptor complexes controls pollen tube reception and rupture inside the targeted ovule. Pollen tube rupture releases the polytubey block at the septum, which allows the emergence of secondary pollen tubes upon fertilization failure. Thus, orchestrated steps in the fertilization process in Arabidopsis are coordinated by the same signaling components to guarantee and optimize reproductive success.},
  author       = {Zhong, Sheng and Li, Ling and Wang, Zhijuan and Ge, Zengxiang and Li, Qiyun and Bleckmann, Andrea and Wang, Jizong and Song, Zihan and Shi, Yihao and Liu, Tianxu and Li, Luhan and Zhou, Huabin and Wang, Yanyan and Zhang, Li and Wu, Hen-Ming and Lai, Luhua and Gu, Hongya and Dong, Juan and Cheung, Alice Y. and Dresselhaus, Thomas and Qu, Li-Jia},
  issn         = {1095-9203},
  journal      = {Science},
  number       = {6578},
  pages        = {290--296},
  publisher    = {American Association for the Advancement of Science},
  title        = {{RALF peptide signaling controls the polytubey block in Arabidopsis}},
  doi          = {10.1126/science.abl4683},
  volume       = {375},
  year         = {2022},
}