Hechtian Strands Transmit Cell Wall Integrity Signals in Plant Cells

Abstract

Hechtian strands are thread-like structures in plasmolyzed plant cells that connect the cell wall to the plasma membrane. Although these strands were first observed more than 100 years ago, their physiological roles are largely unknown. Here, we used intracellular laser microdissection to examine the effects of disrupting Hechtian strands on plasmolyzed tobacco BY-2 cells. When we focused femtosecond laser pulses on Hechtian strands, targeted disruptions were induced, but no visible changes in cell morphology were detected. However, the calcofluor white signals from β-glucans was detected in plasmolyzed cells with disrupted Hechtian strands, whereas no signals were detected in untreated plasmolyzed cells. These results suggest that Hechtian strands play roles in sensing cell wall integrity.

DEAP1 encodes a fasciclin‐like arabinogalactan protein required for male fertility in rice

“…Hechtian strands connect the cell wall to the PM and are implicated in cell adhesion, cell–cell signaling, and cell wall integrity (Yoneda et al, 2020). Several AGPs, including FLAs, are localized on the PM and Hechtian strands and have been proposed to play a role in connecting the PM and the cell wall (Seifert and Roberts, 2007; Seifert et al, 2014; Seifert, 2018; Yoneda et al, 2020). Based on similar protein distributions, we speculated that DEAP1 might play a role in mediating the association between the PM and the cell wall.…”

“…This finding is reminiscent of the Hechtian strands, the stretched PM extensions presented in the adhesion zones. Hechtian strands connect the cell wall to the PM and are implicated in cell adhesion, cell–cell signaling, and cell wall integrity (Yoneda et al, 2020). Several AGPs, including FLAs, are localized on the PM and Hechtian strands and have been proposed to play a role in connecting the PM and the cell wall (Seifert and Roberts, 2007; Seifert et al, 2014; Seifert, 2018; Yoneda et al, 2020).…”

FLA14 is required for pollen development and preventing premature pollen germination under high humidity in Arabidopsis

“…S2). Hechtian strands in the adhesion zones connect the cell wall to the plasma membrane, mechanically transduce cell wall stress signals to receptors located in the plasma membrane and are suggested to be implicated in signal transduction, cell–cell communication events and sensing cell wall integrity [ 68 , 69 ]. Several members of the AGP family, such as LeAGP1 in tomato and FLA4, AtAGP17 and AtAGP18 in Arabidopsis, have been found to be distributed on the plasma membrane and in Hechtian strands and are proposed to be a kind of medium connecting the plasma membrane and cell wall [ 14 , 68 , 70 – 73 ].…”

Mechanosensing, from forces to structures

“…Whereas the importance of cell wall and PM in mechano-sensing is obvious, more and more evidence supports the rational existence of a physical continuum from cell wall to PM, cytoskeletons, and even internal organelles ( Lang et al, 2004 ; Fal et al., 2017 ; Hamant et al., 2019 ; Lee et al., 2019 ; Yoneda et al, 2020 ; Goswami et al., 2020a ; Goswami et al., 2020b ; Fal et al., 2021 ; Schneider et al., 2021 ; Codjoe et al., 2022 ; Radin et al., 2022 ). Once the force transmission chain is a continuum at the cellular level, where are the hotspots for the connection among different compartments is still an open question.…”