Role of miRNAs in Seed Development

Abstract

The formation of seed is initiated after fertilization. Seed development starts with differentiation of tissues at relatively early stages, during which the basic body plan of a future plant is already determined. Later, maturation programs are induced to prepare for seed desiccation, dispersal, and germination. Many transcription factors are involved in the developmental and maturation programs in developing seeds, and these programs are subject to transcriptional, posttranscriptional, and posttranslational regulation. miRNAs are essential for normal seed development. Loss of function in miRNA biogenesis-, processing-, and loading-associated genes results in embryo lethality, severe embryo defects, or abnormal seedling formation after germination. The timing of expression of individual miRNAs also appears to be important. A specific subset of miRNAs and their targets are involved in embryogenesis, while a different subset of miRNAs may be responsible for seed maturation. miRNAs also play a critical role in the separation of these two distinct programs in seeds.