Micrornas In Plant Development And Stress Responses

Precise regulation of gene expression in both time and space is vital to plant growth, development and adaptation to biotic and abiotic stress conditions. This is achieved by multiple mechanisms, with perhaps the most important control being exerted at the level of transcription. However, with the recent discovery of microRNAs another ubiquitous mode of gene regulation that occurs at the post-transcriptional level has been identified. MicroRNAs can silence gene expression by targeting complementary or partially complementary mRNAs for degradation or translational inhibition. Recent studies have revealed that microRNAs play fundamental roles in plant growth and development, as well as in adaptation to biotic and abiotic stresses. This book highlights the roles of individual miRNAs that control and regulate diverse aspects of plant processes.

MicroRNAs (miRNAs) are small (20–24 nt), single stranded, regulatory RNA molecules or gene regulators of critical transcriptional or post-transcriptional gene regulation in plants in sequence-specific order that respond to numerous abiotic stresses and animals, non-coding, highly evolutionarily conserved and widely distributed throughout the plant kingdom. MiRNAs are master regulators of plant growth and development, development attenuation under various environmental stresses by stress-responsive miRNAs and plant stress responses and tolerance. Drought, salinity, heat, cold, UV radiation, heavy metal, pathogens, pests and other microbial infections affect survival, growth, development, quality, yield, and production of plants. Stress induced miRNAs down regulate their target miRNAs. This down regulation leads to the accumulation and function of positive regulators, highlighting their roles in stress responses and tolerance. Plant miRNA mediated modifications include overexpression or repression of stress-responsive miRNAs and/or their target complementary or partially complementary gene products, miRNA-resistant target genes, target-mimics and artificial miRNAs. Thus, miRNAs may serve as "genomic gold mines", novel, potent and potential targets in plant genetic manipulations and miRNA-based biotechnology will aid plant improvement and crop-plant tolerance to different environmental stresses. This book reviews our recent understanding of plant microRNAs, biogenesis and functions, computational tools and bioinformatics, regulation of plant growth and development, expression studies, and the role of plant miRNAs in various biotic and abiotic stress-response regulation in plants.

This book summarizes the latest findings on the functions of microRNAs in the regulation of plant development and responses to the surrounding environment. MicroRNAs are an important class of molecules that can be found in diverse groups of organisms, including plants and animals, and the investigation of their roles is a highly dynamic and “hot” research topic. The respective chapters address four main aspects, namely: microRNA investigation and annotation, the regulatory roles of microRNAs in various developmental processes, in response to abiotic factors, and in the context of biotic stress response regulation. Systematically reviewing the most important findings in this field, the book offers an essential guide for undergraduate and graduate students, teachers, and plant science researchers. Due to the potential applications of microRNAs in crop breeding and plant protection, it also represents a valuable resource for scientists in academia and the private sector alike.

This book summarizes the latest findings on the functions of microRNAs in the regulation of plant development and responses to the surrounding environment. MicroRNAs are an important class of molecules that can be found in diverse groups of organisms, including plants and animals, and the investigation of their roles is a highly dynamic and "hot" research topic. The respective chapters address four main aspects, namely: microRNA investigation and annotation, the regulatory roles of microRNAs in various developmental processes, in response to abiotic factors, and in the context of biotic stress response regulation. Systematically reviewing the most important findings in this field, the book offers an essential guide for undergraduate and graduate students, teachers, and plant science researchers. Due to the potential applications of microRNAs in crop breeding and plant protection, it also represents a valuable resource for scientists in academia and the private sector alike.

Discovered in plants at the turn of the century, microRNAs (miRNAs) have been found to be fundamental to many aspects of plant biology. These small (20–24 nt) regulatory RNAs are derived via processing from longer imperfect double-stranded RNAs. They are then incorporated into silencing complexes, which they guide to (m)RNAs of high sequence complementarity, resulting in gene silencing outcomes, either via RNA degradation and/or translational inhibition. Some miRNAs are ancient, being present in all species of land plants and controlling fundamental processes such as phase change, organ polarity, flowering, and leaf and root development. However, there are many more miRNAs that are much less conserved and with less understood functions. This Special Issue contains seven research papers that span from understanding the function of a single miRNA family to examining how the miRNA profiles alter during abiotic stress or nutrient deficiency. The possibility of circular RNAs in plants acting as miRNA decoys to inhibit miRNA function is investigated, as was the hierarchical roles of miRNA biogenesis factors in the maintenance of phosphate homeostasis. Three reviews cover the potential of miRNAs for agronomic improvement of maize, the role of miRNA-triggered secondary small RNAs in plants, and the potential function of an ancient plant miRNA.

Plants have to manage a series of environmental stresses throughout their entire lifespan. Among these, abiotic stress is the most detrimental; one that is responsible for nearly 50% of crop yield reduction and appears to be a potential threat to global food security in coming decades. Plant growth and development reduces drastically due to adverse effects of abiotic stresses. It has been estimated that crop can exhibit only 30% of their genetic potentiality under abiotic stress condition. So, this is a fundamental need to understand the stress responses to facilitate breeders to develop stress resistant and stress tolerant cultivars along with good management practices to withstand abiotic stresses. Also, a holistic approach to understanding the molecular and biochemical interactions of plants is important to implement the knowledge of resistance mechanisms under abiotic stresses. Agronomic practices like selecting cultivars that is tolerant to wide range of climatic condition, planting date, irrigation scheduling, fertilizer management could be some of the effective short-term adaptive tools to fight against abiotic stresses. In addition, “system biology” and “omics approaches” in recent studies offer a long-term opportunity at the molecular level in dealing with abiotic stresses. The genetic approach, for example, selection and identification of major conditioning genes by linkage mapping and quantitative trait loci (QTL), production of mutant genes and transgenic introduction of novel genes, has imparted some tolerant characteristics in crop varieties from their wild ancestors. Recently research has revealed the interactions between micro-RNAs (miRNAs) and plant stress responses exposed to salinity, freezing stress and dehydration. Accordingly transgenic approaches to generate stress-tolerant plant are one of the most interesting researches to date. This book presents the recent development of agronomic and molecular approaches in conferring plant abiotic stress tolerance in an organized way. The present volume will be of great interest among research students and teaching community, and can also be used as reference material by professional researchers.

This detailed volume provides a collection of protocols for the study of miRNA functions in plants. Beginning with coverage of miRNA function, biogenesis, activity, and evolution in plants, the book continues by guiding readers through methods on the identification and detection of plant miRNAs, bioinformatic analyses, and strategies for functional analyses of miRNAs. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and cutting-edge, Plant MicroRNAs: Method and Protocols aims to ensure successful results in the further study of this vital area of plant science.