Small RNAs, big impacts: How microRNAs help plant survive under adverse environmental conditions
Shuangrong Yuan, Zhigang Li, Dayong Li, Qian Hu &Hong Luo
Genetics (College of Agriculture, Forestry and Life Sciences)
Environmental and nutritional stresses are limiting factors in plant growth and development, especially for the agricultural productivity. Due to the sessile nature of plants, these stresses are unavoidable. To enhance stress resistance of plant, numerous stress responsive genes encoding for particular functional proteins have been identified. However, the comprehensive understanding of plant response to these stresses remains unclear due to the complexity of the stress responsive network. The discovery of plant microRNAs, a class of endogenous small RNAs, sheds light on this question for the reasons that 1) they coordinately regulate multiple genes; 2) they control diverse biological processes, including plant responses to environmental and nutritional stresses. To determine how microRNAs help plant survive under adverse environmental conditions, we generated the transgenic turfgrass with constitutively expressing of a miRNA gene and evaluated its performance under conditions of soil salinity and nitrogen deficiency at morphological, physiological and molecular levels, respectively. Our data demonstrate that transgenic plants exhibit improved tolerance to salt stress and nitrogen starvation. To understand the underlying molecular mechanisms, five abiotic stress responsive genes have been identified as targets of the miRNA. The results indicate the potential of manipulating plant miRNA in improving plant resistance to environmental stresses.