Ferreira Savio Siqueira, Hotta Carlos Takeshi, Poelking Viviane Guzzo de Carli, Leite Debora Chaves Coelho, Buckeridge Marcos Silveira, Loureiro Marcelo Ehlers, Barbosa Marcio Henrique Pereira, Carneiro Monalisa Sampaio, Souza Glaucia Mendes
Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil.
Plant Mol Biol. 2016 May;91(1-2):15-35. doi: 10.1007/s11103-016-0434-2. Epub 2016 Jan 28.
Sugarcane is a hybrid of Saccharum officinarum and Saccharum spontaneum, with minor contributions from other species in Saccharum and other genera. Understanding the molecular basis of cell wall metabolism in sugarcane may allow for rational changes in fiber quality and content when designing new energy crops. This work describes a comparative expression profiling of sugarcane ancestral genotypes: S. officinarum, S. spontaneum and S. robustum and a commercial hybrid: RB867515, linking gene expression to phenotypes to identify genes for sugarcane improvement. Oligoarray experiments of leaves, immature and intermediate internodes, detected 12,621 sense and 995 antisense transcripts. Amino acid metabolism was particularly evident among pathways showing natural antisense transcripts expression. For all tissues sampled, expression analysis revealed 831, 674 and 648 differentially expressed genes in S. officinarum, S. robustum and S. spontaneum, respectively, using RB867515 as reference. Expression of sugar transporters might explain sucrose differences among genotypes, but an unexpected differential expression of histones were also identified between high and low Brix° genotypes. Lignin biosynthetic genes and bioenergetics-related genes were up-regulated in the high lignin genotype, suggesting that these genes are important for S. spontaneum to allocate carbon to lignin, while S. officinarum allocates it to sucrose storage. Co-expression network analysis identified 18 transcription factors possibly related to cell wall biosynthesis while in silico analysis detected cis-elements involved in cell wall biosynthesis in their promoters. Our results provide information to elucidate regulatory networks underlying traits of interest that will allow the improvement of sugarcane for biofuel and chemicals production.
甘蔗是热带种（Saccharum officinarum）和割手密（Saccharum spontaneum）的杂交种，甘蔗属的其他物种和其他属也有少量贡献。了解甘蔗细胞壁代谢的分子基础，可能有助于在设计新能源作物时合理改变纤维质量和含量。这项工作描述了甘蔗原始基因型（热带种、割手密和大茎野生种）以及一个商业杂交种（RB867515）的比较表达谱，将基因表达与表型联系起来，以鉴定用于改良甘蔗的基因。对叶片、未成熟和中间节间进行的寡核苷酸芯片实验，检测到12,621条正义转录本和995条反义转录本。在显示天然反义转录本表达的途径中，氨基酸代谢尤为明显。对于所有采样组织，以RB867515为参照，表达分析分别在热带种、大茎野生种和割手密中揭示了831、674和648个差异表达基因。糖转运蛋白的表达可能解释了不同基因型之间蔗糖的差异，但在高糖度和低糖度基因型之间还发现了组蛋白的意外差异表达。木质素生物合成基因和生物能量相关基因在高木质素基因型中上调，这表明这些基因对于割手密将碳分配到木质素中很重要，而热带种则将碳分配到蔗糖储存中。共表达网络分析确定了18个可能与细胞壁生物合成相关的转录因子，而在计算机分析中检测到其启动子中涉及细胞壁生物合成的顺式元件。我们的结果提供了信息，以阐明感兴趣性状的调控网络，这将有助于改良甘蔗用于生物燃料和化学品生产。
