Irreversibility of the cell wall modification acts as a limiting factor in desiccation tolerance of Oryza sativa ssp. Indica cv MR303

Abstract

Desiccation tolerance has emerged as a potential strategy for crop improvement. However, the application of desiccation tolerance in crops, particularly rice, has been challenging and limited. Studies in angiosperms suggest that desiccation in vegetative tissues shares a common set of genes, developed convergently by modifying shared pathways associated with seed desiccation. The drought-tolerant Oryza sativa ssp. indica cv MR303 has demonstrated the capability to withstand desiccation state for a short period of time. Using this variety, we aim to investigate the factors that limit rice plants from achieving desiccation tolerance. The irreversibility of the cell wall emerges as a primary factor hindering rice plants from acquiring desiccation tolerance. Analysis of cell wall composition and transcriptomic data reveals an accumulation of secondary cell wall components and the expression of cell wall-related genes involved in secondary wall formation and modification, suggesting that these factors could be underlying causes for the irreversibility of the cell wall. Such factors contribute to the rigidity and stiffness of the cell wall, leading to its irreversibility during the rehydration process. This, in turn, impedes the recovery of rice after dehydration.

Keywords

• Desiccation tolerance
• Abiotic stress
• Drought tolerance
• RNA sequencing
• Cell wall