A Sequential Three-Phase Pathway Constitutes Tracheary Element Connection in the Arabidopsis/ Nicotiana Interfamilial Grafts

Zhuying Deng; Huiyan Wu; Tianlin Jin; Tingting Cai; Mengting Jiang; Mi Wang; Dacheng Liang

doi:10.3389/fpls.2021.664342

A Sequential Three-Phase Pathway Constitutes Tracheary Element Connection in the Arabidopsis/ Nicotiana Interfamilial Grafts

Front Plant Sci. 2021 Jul 5:12:664342. doi: 10.3389/fpls.2021.664342. eCollection 2021.

Authors

Zhuying Deng^{1

2}, Huiyan Wu^{1

2}, Tianlin Jin^{1

2}, Tingting Cai^{1

2}, Mengting Jiang^{1

2}, Mi Wang^{1

2}, Dacheng Liang^{1

2}

Affiliations

¹ Hubei Collaborative Innovation Center for Grain Industry, School of Agriculture, Yangtze University, Jingzhou, China.
² Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, China.

Abstract

Scion-rootstock union formation is a critical step toward the functional assemblage of heterogeneous plants. Interfamilial scion-rootstock interaction often results in graft incompatibility during the assemblage process, and the underlying mechanisms are largely unknown. In this study, we reported that tracheary element (TE) remodeling, including TE segmentation and deformation, rather than de novo formation from callus or adjacent tissues, took place at the early stage of grafting interface between Arabidopsis thaliana and Nicotiana benthamiana (At/Nb). Following cellular deposits, the short TEs from both partners were overlapping, dependent on the homogeneity of contacting TEs, with each other. Without overlapping, the TEs at the interface would grow laterally, and the TEs above and below the interface would undergo self-fusion to form insulating spiraling bundles. Finally, the overlapping TEs constituted a continuous network through alignment. Our results provide a definitive framework for the critical process of TE behavior in the At/Nb distant grafts, including (1) segmentation and/or deformation, (2) matching, overlapping, and cellular deposits, and (3) aligning or spiraling. These insights might guide us in the future into constructing more compatible distant grafts from the perspective of TE homogeneity.

Keywords: TE segmentation; aligning; cellular deposits; compatibility; heterograft; incompatibility; short TEs; spiraling tracheary elements.