ABSTRACT

The rate of improvement of sugar content in sugarcane remains low for decades worldwide. Our previous transcriptome studies provided an atlas of sucrose accumulation-related gene expression, but little is known about the proteins involved. Here, we conducted a proteomic analysis of experimentally altered sucrose accumulation in sugarcane. Analysis of stem proteomes of sugarcane ripener ethephon treated high- and low-sugar genotypes had identified 2983 proteins of which 139 were significantly differentially expressed (DEPs). These DEPs were found to be associated with sugar metabolism-related processes with 25 of them may have a regulatory role in sucrose accumulation. The key proteins identified include UDP-glucose 6-dehydrogenase associated with amino sugar and nucleotide sugar metabolism; those involved in carbon fixation; and fructokinase, β-D-glucosidase, and α-glucan phosphorylase involved in starch and sucrose metabolism. Distinct genotype- and ethephon-dependent DEP expression was evident providing new insights into one of the most intractable sugarcane traits to breeding.

摘要

全世界数十年来，甘蔗中糖含量的提高率一直很低。我们以前的转录组研究提供了蔗糖积累相关基因表达图集，但对涉及的蛋白质知之甚少。在这里，我们对甘蔗中蔗糖积累的实验改变进行了蛋白质组学分析。分析甘蔗成熟乙烯利处理过的高糖和低糖基因型的茎蛋白质组，已鉴定出2983个蛋白质，其中139个被显着差异表达（DEPs）。发现这些DEP与糖代谢相关过程有关，其中25种可能在蔗糖积累中起调节作用。鉴定出的关键蛋白包括与氨基糖和核苷酸糖代谢相关的UDP-葡萄糖6-脱氢酶；那些参与碳固定的人；和果糖激酶 β-D-葡萄糖苷酶和α-葡聚糖磷酸化酶参与淀粉和蔗糖的代谢。明显的基因型和乙烯利依赖性DEP表达明显，为育种中最难处理的甘蔗性状之一提供了新见识。