Revitalizing miRNAs mediated agronomical advantageous traits improvement in rice.

One of the key enigmas in conventional and modern crop improvement programmes is how to introduce beneficial traits without any penalty impairment. Rice (Oryza sativa L.), among the essential staple food crops grown and utilized worldwide, needs to improve genotypes in multifaceted ways. With the global view to feed ten billion under the climatic perturbation, only a potent functional master regulator can withstand with hope for the next green revolution and food security. miRNAs are such, miniature, fine tuners for crop improvement and provide a value addition in emerging technologies, namely large-scale genotyping, phenotyping, genome editing, marker-assisted selection, and genomic selection, to make rice production feasible. There has been surplus research output generated since the last decade on miRNAs in rice, however, recent functional knowledge is limited to reaping the benefits for conventional and modern improvements in rice to avoid ambiguity and redundancy in the generated data. Here, we present the latest functional understanding of miRNAs in rice. In addition, their biogenesis, intra- and inter-kingdom signaling and communication, implication of amiRNAs, and consequences upon integration with CRISPR-Cas9. Further, highlights refer to the application of miRNAs for rice agronomical trait improvements, broadly classified into three functional domains. The majority of functionally established miRNAs are responsible for growth and development, followed by biotic and abiotic stresses. Tabular cataloguing reveals and highlights two multifaceted modules that were extensively studied. These belong to miRNA families 156 and 396, orchestrate multifarious aspects of advantageous agronomical traits. Moreover, updated and exhaustive functional aspects of different supplemental miRNA modules that would strengthen rice improvement are also being discussed. The frequency distribution of functionally studied miRNAs in rice is broadly classified to regulate growth and development processes, provide adaptation to sustain themselves under various abiotic stresses, and protect them from a large repertoire of disease-causing agents. [Display omitted] • Yield potential for staple crops, viz. rice, must be enhanced to keep pace with the burgeoning population. • miRNAs are the vital regulators that regulate a plethora of advantageous agronomical traits. • We highlighted and discussed the current update on the functional miRNA module discovery in rice. • Among others, miRNAs 156 and 396 families have been extensively studied to a functional extent. • Such studies will be supportive of the new research design by finding appropriate research gaps. [ABSTRACT FROM AUTHOR]