Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

Abstract

The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens.

Downregulation of p‐COUMAROYL ESTER 3‐HYDROXYLASE in rice leads to altered cell wall structures and improves biomass saccharification

“…First, as mentioned above, the reductions in wall‐cross‐linking FAs should positively affect the saccharification of C3′H ‐KD rice cell walls, logically by reducing interactions between polysaccharides and lignins. In fact, previous studies with artificial cell wall models (Grabber et al ., ,b, ) and with plants harboring various levels of FA (Lam et al ., ; Piston et al ., ; Buanafina et al ., ; Reem et al ., ; de Souza et al ., ) have shown negative correlations between the abundance of wall‐bound FAs and the degradability of grass cell walls. On the other hand, enriched H lignins themselves might also affect cell wall recalcitrance.…”

Re‐targeting of a plant defense protease by a cyst nematode effector

“…Examination of callose deposition and ROS visualization were performed as described (Pogorelko et al ., ; Reem et al ., ).…”

Diverse lignocellulosic feedstocks can achieve high field‐scale ethanol yields while providing flexibility for the biorefinery and landscape‐level environmental benefits

“…This would be expected to have a positive effect on fermentation performance by reducing the concentration of hydroxycinnamates in the biomass and resulting hydrolyzate, but may come at the expense of feedstock viability. Higher hydroxycinnamate contents have been shown to increase plant resistance to herbivory and pathogen infestation, and reductions in these levels can lead to losses in crop yields (Barros-Rios, Santiago, Jung, & Malvar, 2015;Buanafina & Fescemyer, 2012;Reem et al, 2016;Santiago, Barros-Rios, Alvarez, & Malvar, 2016). Alternatively, bioethanol producers could utilize Z. mobilis or other tolerant microbial ethanologens, or reengineer yeast with greater tolerance to hydroxycinnamates and other lignocellulose derived inhibitors, such as has been done with E. coli (Sariaslani, 2007).…”