Allsman, L. A. | bioRxiv Science

bioRxiv2025

KATANIN promotes cell elongation and division to generate proper cell numbers in maize organs

Microtubule severing is essential for proper eukaryotic cell elongation and division. Here we show that the microtubule severing protein, KATANIN, is encoded by two genes in Zea mays (maize) called Discordia3a (Dcd3a) and Dcd3b. Loss of function allele combinations contribute to reduced microtubule severing and decreased cell elongation. The latter results in reduced cell number by slowing entry into mitosis. KATANIN is important for preprophase band (PPB) formation and positioning, and nuclear positioning in symmetric cell divisions. A combination of these defects contributes to generating mutant plants with small size and aberrant shape.

plant biology↗

bioRxiv2024

De Novo TANGLED1 Recruitment to Aberrant Cell Plate Fusion Sites in Maize

Division plane positioning is critical for proper growth and development in many organisms. In plants, the division plane is established before mitosis, by accumulation of a cytoskeletal structure called the preprophase band (PPB). The PPB is thought to be essential for recruitment of division site localized proteins, which remain at the division site after the PPB disassembles. Here, we show that a division site localized protein, TANGLED1 (TAN1), is recruited independently of the PPB to the cell cortex at sites, by the plant cytokinetic machinery, the phragmoplast. TAN1 recruitment to de novo sites on the cortex is partially dependent on intact actin filaments and the myosin XI motor protein OPAQUE1 (O1). These data imply a yet unknown role for TAN1 and possibly other division site localized proteins during the last stages of cell division when the phragmoplast touches the cell cortex to complete cytokinesis. Summary StatementThe plant division site protein TANGLED1 is recruited to de novo cell plate insertion sites independently of the preprophase band.

plant biology↗