Structural properties of mixed-linked betaglucan and callose in the formation of aerenchyma in sugarcane

• Grant number: 24/21116-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Marcos Silveira Buckeridge
• Grantee: Grayce Hellen Romim Silva
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Sugarcane is studied for biotechnological potential, particularly in bioethanol production. Understanding the structure of the cell wall constitutes a strategy for generating knowledge on how to access these sugars. The aerenchyma formation in sugarcane roots has proven to be a promising model for understanding how the plant modifies its cell walls, revealing the polysaccharides and enzymes involved. Some studies on this process in sugarcane have shown that modification of a mixed-linkage betaglucan facilitates access to other polysaccharides in the cell wall. The identification of a transcription factor called ScRAV1 revealed that it plays a role in controlling hormonal balance by acting negatively on an endopolygalacturonase. However, the mechanisms of this signaling are not yet fully understood. Another identified polysaccharide was callose, a regulator of intercellular flow, which is degraded during aerenchyma formation, a process mediated by the glycosyl hydrolase GH17. In OXScRAV1 plants, the overexpression of the ScRAV1 gene increased the presence of callose and mixed-linkage betaglucan, delaying aerenchyma formation but without preventing the process, raising questions about the actual role of these polysaccharides throughout the process. Given this, the project aims to investigate the relationship between these two polysaccharides in aerenchyma formation in OXScRAV1 plants, seeking to understand their structural properties and how they may impact cell trafficking and cell wall properties during aerenchyma formation in sugarcane.