Does suberin accumulation in plant roots contribute to waterlogging tolerance?

Abstract

Plants that are adapted to waterlogged conditions develop aerenchyma in roots for ventilation. Some wetland plant species also form an apoplastic barrier at the outer cell layers of roots that reduces radial oxygen loss (ROL) from the aerenchyma and prevents toxic compounds from entering the root. The composition of the apoplastic barrier is not well understood. One potential component is suberin, which accumulates at the hypodermal/exodermal cell layers of the roots under waterlogged soil conditions or in response to other environmental stimuli. However, differences in suberin content and composition between plant species make it difficult to evaluate whether suberin has a role in preventing ROL. In this article, we summarize recent advances in understanding apoplastic barrier formation in roots and, between various plant species, compare the chemical compositions of the apoplastic barriers in relation to their permeability to oxygen. Moreover, the relationship between suberin accumulation and the barrier to ROL is discussed.

A major locus involved in the formation of the radial oxygen loss barrier in adventitious roots of teosinte Zea nicaraguensis is located on the short‐arm of chromosome 3

“…Suberin and lignin have been proposed as components of the root ROL barrier (reviewed by Watanabe et al . ), with circumstantial evidence for involvement of suberin but not lignin in roots of rice (cv. Nipponbare) (Shiono et al .…”

Rice acclimation to soil flooding: Low concentrations of organic acids can trigger a barrier to radial oxygen loss in roots

“…However, the signalling network involved is unknown (Colmer et al, ; Yamauchi et al, ). The increased resistance to radial movement of O 2 is associated with deposition of suberin and/or lignin in the hypodermal or exodermal cell walls in roots of rice (Kotula et al, ; Watanabe, Nishiuchi, Kulichikhin, & Nakazono, ) and other species (Kotula, Schreiber, Colmer, & Nakazono, ; Soukup, Armstrong, Schreiber, Franke, & Votrubová, ; Watanabe et al, ; Yamauchi et al, ), although induction of a ROL barrier can occur within 2 days and the changes involved are more subtle than those detectable using histochemical stains (Shiono et al, ). Similar to the lack of any clear histochemical difference for roots of rice with a functional ROL barrier induced by 2 days in stagnant agar medium as compared with aerated controls (Shiono et al, ), in the present study, the staining for suberin of root cross sections at 50 mm behind the root apex, a position with ROL barrier induction (Figure ), also did not show any marked differences for suberin in the hypodermal or exodermal layer (Figure ).…”

DNA Marker-Assisted Selection Approach for Developing Flooding-Tolerant Maize

“…The ROL barrier is also important for flooding tolerance because it facilitates oxygen diffusion to root apices by preventing radial loss of oxygen from the roots (Colmer 2003, Watanabe et al 2013). Most recently, our collaborators at Nagoya University have succeeded in identifying the chromosome location of a QTL for ROL barrier (Nakazono et al 2015).…”