ABSTRACT
Non-coding RNAs (ncRNAs) have appeared as important components of the gene regulatory system across a plethora of plant ecosystems. In particular, the 20–30 nucleotide small ncRNAs (sRNAs) play important roles in gene expression during plant growth, mediating developmental processes and responses to biotic stresses. MicroRNAs (miRNAs) are a class of 20 - 24 nucleotide endogenous small RNAs that play an important role in gene expression during plant growth, mediating developmental processes and responses to biotic stresses. The past decade has witnessed an explosion in our knowledge of the role of miRNAs in various biological processes in plants. miRNAs in plants control the expression of gene encoding transcription factors, stress response proteins, and other proteins that influence the growth, development, and physiology of plants. The regulation of gene expression is an important aspect of various biological phenomena that take place in plant physiology and, thus, creates our beautiful fauna. Generally, functional protein-coding genes are controlled by many different types of tans-acting factors, such as transcription factors. Thus, there is no doubt that there is much evidence indicating that these transcription factors play a critical role in plant growth and development, stress response, and the crosstalk in different signal transduction pathways. This chapter provides an overview of the studies involving detailed elaboration related to the current progress of miRNA-controlled plant development, growth, leaf and root system regulation, and plant floral transition and pleiotropic developmental defects to specific developmental processes, such as SAM regulation in plant physiology. In addition, this chapter also summarizes miRNAs that are experimentally proven to affect crop quality and productivity. Current reports also show that a single miRNA usually displays multiple regulatory roles, such as phase transition and the development of organ and stresses responses. The focus of this chapter serves as a brief introduction related to the role of miRNAs on plant physiology.
