Format

Send to

Choose Destination
Plant Sci. 2015 Jul;236:272-82. doi: 10.1016/j.plantsci.2015.04.007. Epub 2015 Apr 28.

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

Author information

1
Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193 Cerdanyola del Valles, Barcelona, Spain. Electronic address: silvia.fornale@cragenomica.es.
2
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain. Electronic address: jrencoret@irnase.csic.es.
3
Área de Fisiología Vegetal, Universidad de León, 24071 León, Spain. Electronic address: lgarc@unileon.es.
4
Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193 Cerdanyola del Valles, Barcelona, Spain. Electronic address: montse.capellades@cragenomica.es.
5
Área de Fisiología Vegetal, Universidad de León, 24071 León, Spain. Electronic address: a.encina@unileon.es.
6
Agrobiología Ambiental, Calidad de Suelos y Plantas (UVIGO) (unidad asociada a la Misión Biológica de Galicia, CSIC), Dpto. Biología Vegetal y Ciencias del Suelo, Facultad de Biología, Universidad de Vigo, Campus As Lagoas Marcosende, 36310, Vigo, Spain. Electronic address: rsantiago@mbg.csic.es.
7
Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193 Cerdanyola del Valles, Barcelona, Spain. Electronic address: joan.rigau@cragenomica.es.
8
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain. Electronic address: anagu@irnase.csic.es.
9
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain. Electronic address: delrio@irnase.csic.es.
10
Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193 Cerdanyola del Valles, Barcelona, Spain. Electronic address: david.caparros@cragenomica.es.

Abstract

Coumarate 3-hydroxylase (C3H) catalyzes a key step of the synthesis of the two main lignin subunits, guaiacyl (G) and syringyl (S) in dicotyledonous species. As no functional data are available in regards to this enzyme in monocotyledonous species, we generated C3H1 knock-down maize plants. The results obtained indicate that C3H1 participates in lignin biosynthesis as its down-regulation redirects the phenylpropanoid flux: as a result, increased amounts of p-hydroxyphenyl (H) units, lignin-associated ferulates and the flavone tricin were detected in transgenic stems cell walls. Altogether, these changes make stem cell walls more degradable in the most C3H1-repressed plants, despite their unaltered polysaccharide content. The increase in H monomers is moderate compared to C3H deficient Arabidopsis and alfalfa plants. This could be due to the existence of a second maize C3H protein (C3H2) that can compensate the reduced levels of C3H1 in these C3H1-RNAi maize plants. The reduced expression of C3H1 alters the macroscopic phenotype of the plants, whose growth is inhibited proportionally to the extent of C3H1 repression. Finally, the down-regulation of C3H1 also increases the synthesis of flavonoids, leading to the accumulation of anthocyanins in transgenic leaves.

KEYWORDS:

Cell wall polysaccharides; Degradability; Flavonoids; Lignin; Maize

PMID:
26025540
DOI:
10.1016/j.plantsci.2015.04.007
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center