Identification of novel factors that increase enzymatic saccharification efficiency in Arabidopsis wood cells

Abstract

Developing methods to efficiently convert lignocellulosic polymers, i.e. cellulose, hemicellulose, and lignin into user-friendly carbon resources, such as fermentable sugars, is critical for improving plant biomass utilization. Here, we report the identification of genes that increase enzymatic saccharification efficiency in cultured Arabidopsis wood cells. We overexpressed a set of genes that were upregulated during the early stages of in vitro xylem vessel cell differentiation, including transcription factor and CAZYme genes, in Arabidopsis and tested their effects on enzymatic saccharification efficiency. Of the 96 transgenic seedlings sampled, 37 and 17 lines showed significant increases and decreases in glucose yields, respectively. Further analysis of 20 overexpression lines with high glucose yields in seedling samples indicated that compared to wild type, the glucose and xylose yields from inflorescence stem samples were higher in lines overexpressing genes encoding BETA-XYLOSIDASE 2, UDP-GLUCOSYL TRANSFERASE 88A1, AT3G15350 (a class GT14 glycosyltransferase protein), and the Dof-type transcription factor Dof4.6, whose detailed molecular functions have not yet been characterized. No apparent defect in growth or inflorescence stem structure was detected in these overexpression lines. Therefore, these four genes might represent novel factors that can be used to increase saccharification efficiency in wood tissues without negatively affecting total biomass production. Furthermore, our results confirm the validity of our screening strategy for isolating factors related to the saccharification efficiency of lignocellulosic biomass.

QTL Identification for Stem Fiber, Strength and Rot Resistance in a DH Population from an Alien Introgression of Brassica napus

“…In this region, BnaA07g26180 corresponding to AT1G02640 was identified as candidate gene, encoding a protein similar to a beta-xylosidase. It was reported that overexpressing this gene could increase enzymatic saccharification efficiency in cultured Arabidopsis wood cells [ 46 ].…”

Identifying transcription factors that reduce wood recalcitrance and improve enzymatic degradation of xylem cell wall in Populus

“…Overall, our results suggested that only approximately 10% of the selected TF up-regulated during wood formation increased enzymatic saccharification, therefore, the first seedling screening method in this study was effective to find transgenic lines with the improve enzymatic digestibility. In Arabidopsis , a similar approach successfully identified several cell-wall-related TF genes that increase cell wall saccharification efficiency 49 .…”

Enhancement of Secondary Cell Wall Formation in Poplar Xylem Using a Self-Reinforced System of Secondary Cell Wall-Related Transcription Factors

“…The powdered stem samples were treated with a mixture of cellulase from Trichoderma reesei ATCC 26921 (Sigma-Aldrich, Merck KgaA, Darmstadt, Germany) and cellobiase from Aspergillus niger (Sigma-Aldrich, Merck KgaA) for 24 h, according to the methods of Okubo-Kurihara et al (2016) and Ohtani et al (2017b) . The supernatant was collected after centrifugation, after which 0.1 M NaOH solution was added to stop the reaction.…”