Multifarious Activity of Silicon in Sugarcane Productivity Escalation: Regulatory Mechanisms and Future Outlook

Abstract

In the current scenario, biotic and abiotic pressures driven by climate change pose serious obstacles to sugarcane cultivation and highly risk for global production. Silicon (Si), a quasi-essential element has been shown to significantly increase sugarcane productivity and related attributes under stressful conditions. Si-transporters such as LSi1, LSi2, and LSi6 are found in the sugarcane roots that essential for intake, transport, and accumulation of Si within the plants. Since, Si deposition creates a barrier against pests and diseases in sugarcane tissues, this movement is crucial for reducing stressors, consequently rate of photosynthesis, LAI, DMP, shoot count and biomass output was enhanced. In seedling and tillering stages of sugarcane, Si application increased the activity of enzymes hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and superoxide dismutase (SOD), while peroxidase activity (POD) was decreased. This led to buildup of reactive oxygen species (ROS), which in turn prompted defence response. But at the jointing stage, MDA and H₂O₂ levels dropped while, SOD and POD activity increased all of which helped to remove excessive ROS. Si may regulate chitinase, β-1,3 glucanase, polyphenoloxidase (PPO), and phenylalanine ammonia-lyase (PAL); additionally, phenol and lignin amounts of sugarcane leaves were noticeably higher. Si improved the bacterial network in the rhizosphere soil, which might have facilitated the growth at critical stage of sugarcane. Si enhanced antimicrobial activity resulted in a twofold impact for suppression of bacteria Leuconostoc spp in post-harvest deterioration losses and also regulated the sucrose inversion process. At the molecular level, Si is essential for reducing metal phytotoxicity through the transcriptional alteration of phytochelatin genes and metal transporters. It also offers insightful information about the ways in which Si functions through an in-depth assessment of sugarcane and it helps researchers, agronomists, and policymakers develop sustainable strategies that will ensure the productivity and resilience of sugarcane in a context of changing environmental hardships.