Discovery of small RNAs in wheat: a survey

Abstract

Several studies related to plant-environment interactions have persistently conveyed the detrimental effects of changing environment on crop productivity. Additionally, alarming rise in population growth has necessitated substantial increase in food production to ensure global food security. World-wide, wheat is a staple dietary crop for humans. Like other crop systems, productivity of wheat is largely dependent on its growth and development, which in turn, is regulated by environmental conditions, including abiotic and biotic stress factors. Under natural conditions, plants are exposed to a multitude of abiotic stresses, either simultaneously or sequentially, which exacerbates their adverse effects. It is therefore necessary to understand the mechanism of stress response in wheat, so that suitable strategies are devised for enhancement of stress tolerance. In this context, concerted research efforts involving breeding programs as well as transgenic development are needed for developing improved and locally adapted wheat varieties. In the recent years, small RNAs, 21–24 nucleotides (nt) long non-coding RNAs, have emerged as crucial regulators of gene expression changes that modulate physiological responses against environmental challenges. In this review, an attempt has been made to present the progress done in the field of wheat small RNAs genomics. An anecdote of small RNA discoveries, their function and regulation during various biotic, abiotic stresses and distinct stages of wheat development is compiled. This information would benefit wheat researchers in devising appropriate strategies for engineering plants with enhanced tolerance to different stress conditions.