Comparative feedstock analysis in Setaria viridis L. as a model for C4 bioenergy grasses and Panicoid crop species

Abstract

Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize), Sorghum bicolor (L.) Moench (sorghum), and Saccharum officinarum L. (sugar cane) as well as promising second generation perennial feedstocks including Miscanthus×giganteus and Panicum virgatum L. (switchgrass). The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet) is a rapid cycling C4 panicoid grass with a relatively small and sequenced diploid genome and abundant seed production. Stable, transient, and protoplast transformation technologies have also been developed for Setaria viridis making it a potentially excellent model for other C4 bioenergy grasses. Here, the lignocellulosic feedstock composition, cellulose biosynthesis inhibitor response and saccharification dynamics of Setaria viridis are compared with the annual sorghum and maize and the perennial switchgrass bioenergy crops as a baseline study into the applicability for translational research. A genome-wide systematic investigation of the cellulose synthase-A genes was performed identifying eight candidate sequences. Two developmental stages; (a) metabolically active young tissue and (b) metabolically plateaued (mature) material are examined to compare biomass performance metrics.

Mapping of a Cellulose-Deficient Mutant Named dwarf1-1 in Sorghum bicolor to the Green Revolution Gene gibberellin20-oxidase Reveals a Positive Regulatory Association between Gibberellin and Cellulose Biosynthesis

“…(Petti et al, 2013). Based on bioinformatic data available, we annotated a total of eight Sorghum sp.…”

“…To standardize the comparison, tissue was staged (Petti et al, 2013) and used for biological and technical replicates. Whole stems were used, and leaves of identical position and age were collected from the mutant and the wild type.…”

Cultura de células em suspensão como ferramenta para estudos em parede celular secundária em gramí­neas C4

“…1A, B) (Li and Brutnell, 2011b;Petti et al, 2013b). S. viridis originou-se na Ásia, sendo domesticada há cerca de 8000 anos atrás no norte da China (Hunt et al, 2008), e desde então espalhou-se em uma extensa gama de habitats em regiões tropicais, subtropicais e temperadas (Dekker, 2003).…”

“…Por outro lado, B. distachyon emergiu como um potencial modelo genético pelo menor tempo de geração, pequeno porte, menor requerimento para cultivo, genoma relativamente pequeno e sequenciado e protocolos de transformação eficientes (Brkljacic et al, 2011;Brutnell et al, 2015). Entretanto, mesmo dentro de gramíneas existem diferenças fisiológicas importantes, sendo a principal e mais notável os diferentes mecanismos fotossintéticos (Petti et al, 2013b). Enquanto B. distachyon é uma gramínea de clima temperado e com fotossíntese C3, a maior parte das gramíneas de interesse econômico apresentam fotossíntese C4, ocorrendo em ambientes tropicais e semi-tropicais (Brutnell et al, 2015 (Petti et al, 2013b).…”

“…Entretanto, mesmo dentro de gramíneas existem diferenças fisiológicas importantes, sendo a principal e mais notável os diferentes mecanismos fotossintéticos (Petti et al, 2013b). Enquanto B. distachyon é uma gramínea de clima temperado e com fotossíntese C3, a maior parte das gramíneas de interesse econômico apresentam fotossíntese C4, ocorrendo em ambientes tropicais e semi-tropicais (Brutnell et al, 2015 (Petti et al, 2013b).…”