MAIZEWALL. Database and Developmental Gene Expression Profiling of Cell Wall Biosynthesis and Assembly in Maize

Abstract

An extensive search for maize (Zea mays) genes involved in cell wall biosynthesis and assembly has been performed and 735 sequences have been centralized in a database, MAIZEWALL (http://www.polebio.scsv.ups-tlse.fr/MAIZEWALL). MAIZE-WALL contains a bioinformatic analysis for each entry and gene expression data that are accessible via a user-friendly interface. A maize cell wall macroarray composed of a gene-specific tag for each entry was also constructed to monitor global cell wall-related gene expression in different organs and during internode development. By using this macroarray, we identified sets of genes that exhibit organ and internode-stage preferential expression profiles. These data provide a comprehensive fingerprint of cell wall-related gene expression throughout the maize plant. Moreover, an in-depth examination of genes involved in lignin biosynthesis coupled to biochemical and cytological data from different organs and stages of internode development has also been undertaken. These results allow us to trace spatially and developmentally regulated, putative preferential routes of monolignol biosynthesis involving specific gene family members and suggest that, although all of the gene families of the currently accepted monolignol biosynthetic pathway are conserved in maize, there are subtle differences in family size and a high degree of complexity in spatial expression patterns. These differences are in keeping with the diversity of lignified cell types throughout the maize plant.

Silencing CHALCONE SYNTHASE in Maize Impedes the Incorporation of Tricin into Lignin and Increases Lignin Content

“…The relation between TAL and PAL activity has been reported by Rö sler et al (1997) for maize and by Cass et al (2015) for brachypodium. Enzymes involved in the general phenylpropanoid (PAL, TAL, C4H, 4CL, HCT, C3H, and CCoAOMT) and monolignol-specific (CCR, F5H, COMT, and CAD) pathways are described by Guillaumie et al (2007). Homologs for the Arabidopsis HCALDH (Nair et al, 2004) are present in maize (Koncitíková et al, 2015;Missihoun et al, 2016).…”

Genetic and physical fine mapping of the novel brown midrib gene bm6 in maize (Zea mays L.) to a 180 kb region on chromosome 2

“…Most of the monolignol biosynthesis genes, except F5H, are regulated by transcription factors MYB58/ 63/85 through AC elements or more degenerate AC elements (Zhou et al 2009;Zhao et al 2010). Investigating the differential gene expression by bm1-4 isogenic lines, Guillaumie et al (2007aGuillaumie et al ( , 2007b identified other transcription factors and regulatory genes besides MYB factors showing differential expression between regular and mutant isogenic lines. Among them were three zinc finger like protein coding genes.…”

“…bm1 was associated with reduced activity of cinnamyl alcohol dehydrogenase 2 (CAD2) gene (Halpin et al 1998). CAD is responsible for converting hydroxycinnamylaldehydes into alcohols in monolignol biosynthesis (Guillaumie et al 2007b). Thus reduced CAD activity resulted in accumulated aldehyde and reduced monlignol units in the lignin (Barrière et al 2004b).…”

Cell wall modifications triggered by the down-regulation of Coumarate 3-hydroxylase-1 in maize

“…Although the maize genome contains two C3H genes, ZmC3H1 (GRMZM2G138074) and ZmC3H2 (GRMZM2G140817), it was initially thought that ZmC3H was encoded by a single gene whose expression pattern is compatible with a possible involvement in lignification [32] and association studies of the maize genetic variation in the phenylpropanoid pathway and forage 6 quality identified a non-synonymous SNP in the terminal exon of C3H1 associated with the in vitro digestibility of organic matter (IVDOM) [33].…”

“…Total diferulates were calculated as the sum of Only one sequence corresponding to a putative C3H (here defined as ZmC3H1) was initially found in maize [32,33]. The ZmC3H1 gene exhibited relatively low levels of expression in all organs studied (roots, young stem, leaves, basal and ear internodes), with slightly higher levels in the ear internode, where a striking switch of gene expression toward phenylpropanoid metabolism occurs, suggesting a high metabolic demand for lignin precursors [32]. In addition, gene expression analyses from microarray databases [63] show that ZmC3H1 is mainly expressed in the aerial parts of the maize plants and is undetectable in non-lignifying tissues ( Supplementary Fig.…”