MicroRNA169 integrates multiple factors to modulate plant growth and abiotic stress responses

Non-coding RNAs in plant stress responses: molecular insights and agricultural applications

Non-coding RNAs (ncRNAs) have emerged as crucial regulators in plant responses to environmental stress, orchestrating complex networks that finetune gene expression under both abiotic and biotic challenges. To elucidate this intricate ncRNA crosstalk, this review comprehensively summarizes recent advances in understanding the mechanisms of key regulatory ncRNAs including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), tRNA derived fragments (tRFs) and small interfering RNAs (siRNAs) in mediating plant adaptations to stress conditions. We discuss molecular insights into how these ncRNAs modulate stress signalling pathways, control hormonal responses and interact through elaborate crosstalk mechanisms. We also emphasize emerging biotechnological strategies that leverage both innate and artificial ncRNAs as well as potential approaches for finetuning ncRNA levels to engineer stress-resilient crops. Collectively, continued advances in high-throughput sequencing, functional genomics and computational modelling will deepen our understanding of ncRNA network mediated stress responses, ultimately guiding the design of robust climate-resilient crops.

Unravelling the interplay between plant miRNAs and plant secondary metabolites: A new frontier in cross- kingdom regulatory mechanisms

MicroRNAs (miRNAs) are also known as single-stranded RNAs with 18-24 nucleotides and exhibit substantial conservation. They represent a class of innate RNAs that are essential for plant cell development, division, differentiation, proliferation, and death. The reported pharmacological effects of plant-derived secondary metabolites contribute to their therapeutic potential. Plant-derived miRNAs have drawn considerable interest as a result of their active involvement in these plant secondary metabolites (PSM). PSMs can be absorbed via diet, and exert a wide range of their therapeutic potential, via exogenous and endogenous interactions. The recent identification of plant miRNAs in controlling the expression of certain genes in mammals has attracted a lot of attention and created new opportunities for studying cross-kingdom regulatory mechanisms in biological research. This review discusses the role of miRNAs in plants, with focus on PSMs via cross-kingdom. The aim is to provide a conceptual theoretical framework based on the involvement of plant miRNA with secondary metabolites and being used as a transfer molecule for cross-kingdom gene regulation. Plant miRNAs' diverse expression patterns and ability to affect several physiological and developmental processes make them promising candidates for advancing preclinical research.

Silencing of miR169a improves drought stress by enhancing vascular architecture, ROS scavenging, and photosynthesis of Solanum tuberosum L

Vascular bundles regulate water balance, nutrient uptake and transport, and stress responses, ultimately influencing the yield and quality of crops. However, our understanding of the genetic functions of microRNAs (miRNAs) during vascular development remains limited. In this research, the role of miR169a in potatoes was studied. Silencing StmiR169a in potatoes promoted vascular bundle formation, resulting in not only upright and robust stems but also longer roots and more extensive root systems. Histological analysis revealed a significant increase in the number of xylem vessels in the vascular bundles of stems and roots of RNAi-mediated miR169a lines (STTM169). Silencing miR169a led to higher water use efficiency, enhanced photosynthesis rates, elevated enzymatic antioxidant activity, and reduced levels of reactive oxygen species (ROS), thereby enhancing the drought resistance of potatoes. However, overexpression of miR169a lines (OE169a) showed the opposite effects. The nuclear factor Y subunit NF-YA3 was identified as a target gene of StmiR169a. The miR169a/NF-YA3 module may be involved in the regulation of potato vascular bundle development and the response to drought stress.

miRNAs: Primary modulators of plant drought tolerance

Drought is a principal environmental factor that affects the growth and development of plants. Accordingly, plants have evolved adaptive mechanisms to cope with adverse environmental conditions. One of the mechanisms is gene regulation mediated by microRNAs (miRNAs). miRNAs are regarded as primary modulators of gene expression at the post-transcriptional level and have been shown to participate in drought stress response, including ABA response, auxin signaling, antioxidant defense, and osmotic regulation through downregulating the corresponding targets. miRNA-based genetic reconstructions have the potential to improve the tolerance of plants to drought. However, there are few precise classification and discussion of miRNAs in specific response behaviors to drought stress and their applications. This review summarized and discussed the specific response behaviors of miRNAs under drought stress and the role of miRNAs as regulators in the response of plants to drought and highlighted that the modification of miRNAs might effectively improve the tolerance of plants to drought.