Calderan-Rodrigues Maria Juliana, de Barros Dantas Luíza Lane, Cheavegatti Gianotto Adriana, Caldana Camila
Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany.
Centro de Tecnologia Canavieira, Piracicaba, Brazil.
Front Plant Sci. 2021 Feb 19;12:637166. doi: 10.3389/fpls.2021.637166. eCollection 2021.
Sugarcane ( spp.), a C grass, has a peculiar feature: it accumulates, gradient-wise, large amounts of carbon (C) as sucrose in its culms through a complex pathway. Apart from being a sustainable crop concerning C efficiency and bioenergetic yield per hectare, sugarcane is used as feedstock for producing ethanol, sugar, high-value compounds, and products (e.g., polymers and succinate), and bioelectricity, earning the title of the world's leading biomass crop. Commercial cultivars, hybrids bearing high levels of polyploidy, and aneuploidy, are selected from a large number of crosses among suitable parental genotypes followed by the cloning of superior individuals among the progeny. Traditionally, these classical breeding strategies have been favoring the selection of cultivars with high sucrose content and resistance to environmental stresses. A current paradigm change in sugarcane breeding programs aims to alter the balance of C partitioning as a means to provide more plasticity in the sustainable use of this biomass for metabolic engineering and green chemistry. The recently available sugarcane genetic assemblies powered by data science provide exciting perspectives to increase biomass, as the current sugarcane yield is roughly 20% of its predicted potential. Nowadays, several molecular phenotyping tools can be applied to meet the predicted sugarcane C potential, mainly targeting two competing pathways: sucrose production/storage and biomass accumulation. Here we discuss how molecular phenotyping can be a powerful tool to assist breeding programs and which strategies could be adopted depending on the desired final products. We also tackle the advances in genetic markers and mapping as well as how functional genomics and genetic transformation might be able to improve yield and saccharification rates. Finally, we review how "omics" advances are promising to speed up plant breeding and reach the unexplored potential of sugarcane in terms of sucrose and biomass production.
甘蔗（甘蔗属）是一种C4植物，具有一个独特的特征：它通过一条复杂的途径，在其茎中以蔗糖的形式梯度累积大量的碳（C）。除了在碳效率和每公顷生物能源产量方面是一种可持续作物外，甘蔗还被用作生产乙醇、糖、高价值化合物和产品（如聚合物和琥珀酸）以及生物电的原料，因而获得了世界领先生物质作物的称号。商业品种，即具有高倍性和非整倍性的杂交种，是从合适的亲本基因型之间的大量杂交中筛选出来的，然后在后代中克隆优良个体。传统上，这些经典育种策略一直倾向于选择蔗糖含量高且抗环境胁迫的品种。甘蔗育种计划目前的一个范式转变旨在改变碳分配的平衡，以此作为一种手段，在将这种生物质用于代谢工程和绿色化学的可持续利用中提供更大的可塑性。最近由数据科学驱动的甘蔗遗传组装提供了令人兴奋的前景，可提高生物量，因为目前甘蔗产量大约仅为其预测潜力的20%。如今，可以应用几种分子表型分析工具来实现预测的甘蔗碳潜力，主要针对两条相互竞争的途径：蔗糖生产/储存和生物量积累。在这里，我们讨论分子表型分析如何能够成为协助育种计划的有力工具，以及根据所需的最终产品可以采用哪些策略。我们还探讨了遗传标记和图谱绘制方面的进展，以及功能基因组学和遗传转化如何能够提高产量和糖化率。最后，我们回顾了“组学”进展如何有望加速植物育种，并挖掘甘蔗在蔗糖和生物量生产方面尚未开发的潜力。
