A Review of the Roles of Non- Coding RNAs Associated with Drought Stress Response in Cassava (Manihot esculenta Crantz)

Cassava is a tuberous root crop that offers food and nutrition security for vulnerable populations, especially in the developing world. The crop is climate-resilient, widely adaptable to varied environments, and tolerant to most abiotic stresses such as drought. It is easy to propagate and can produce significant yield under low input levels compared to other major crops. Cassava’s inherent tolerance to drought stress has been linked with various morpho-physiological and molecular mechanisms. Although major molecular pathways and genes activated under drought stress have been described, cassava drought stress tolerance mediated by non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have not been exhaustively elucidated. This review, therefore, consolidates recent progress that has been made towards the discovery and characterization of miRNAs and lncRNAs in cassava response to drought stress. The review details the omics approaches used in various studies to discover miRNAs and lncRNAs and their over-arching functions in several physiological and molecular mechanisms in cassava under drought.