Prospects of ‘Omic’ Approaches towards Accelerating Sugarcane Improvement: Recent Advancements and Challenges

Sugarcane is an economically important crop and is cultivated throughout the world for its sugar and ethanol. Present sugarcane varieties are derived from inter-specific hybridization between Saccharum officinarum and Saccharum spontaneum, resulting in highly polyploid and aneuploid plants with chromosomes ranging from 80 to 120. This complex nature has hindered advances in marker assisted breeding of this crop. Though an array of methodologies have been adopted by different research groups from all over the world who have well established protocols for developing genetically modified (GM) sugarcane. Several genes of economic interest have been transformed in sugarcane, despite variable success in transgene integration and expression. Recently, genome editing approaches (the zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and CRISPR/Cas9 system) have opened new and unique opportunities for researchers to enhance crop production. However, as far as sugarcane is considered, there are still several challenges/constraints (large genome size, polyploidy, low transformation efficiency, transgene silencing and lack of high throughput screening techniques) ahead that deter sugarcane improvement through genetic engineering and need to be resolved to achieve a complete exploitation of the crop through these biotechnological tools. This review is an attempt to unravel the various sugarcane genomic approaches and their applications towards accelerating sugarcane improvement.