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Article
Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis
Journal of Visual Experiments (2014)
  • Sang-Hyuck Park, University of Arizona
  • Rebecca G. Ong
  • Chuansheng Mei, The Institute for Advanced Learning and Research
Abstract
To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is needed to open up the structure of the plant cell wall, increasing the accessibility of the cell wall carbohydrates. Lignin, a polyphenolic material present in many cell wall types, is known to be a significant hindrance to enzyme access. Reduction in lignin content to a level that does not interfere with the structural integrity and defense system of the plant might be a valuable step to reduce the costs of bioethanol production. In this study, we have genetically down-regulated one of the lignin biosynthesis-related genes, cinnamoyl-CoA reductase (ZmCCR1) via a double stranded RNA interference technique. The ZmCCR1_RNAi construct was integrated into the maize genome using the particle bombardment method. Transgenic maize plants grew normally as compared to the wild-type control plants without interfering with biomass growth or defense mechanisms, with the exception of displaying of brown-coloration in transgenic plants leaf mid-ribs, husks, and stems. The microscopic analyses, in conjunction with the histological assay, revealed that the leaf sclerenchyma fibers were thinned but the structure and size of other major vascular system components was not altered. The lignin content in the transgenic maize was reduced by 7-8.7%, the crystalline cellulose content was increased in response to lignin reduction, and hemicelluloses remained unchanged. The analyses may indicate that carbon flow might have been shifted from lignin biosynthesis to cellulose biosynthesis. This article delineates the procedures used to down-regulate the lignin content in maize via RNAi technology, and the cell wall compositional analyses used to verify the effect of the modifications on the cell wall structure.
Disciplines
Publication Date
2014
DOI
10.3791/51340
Citation Information
Sang-Hyuck Park, Rebecca G. Ong and Chuansheng Mei. "Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis" Journal of Visual Experiments (2014)
Available at: http://works.bepress.com/rebecca-ong/4/