Regulatory roles of noncoding RNAs in callus induction and plant cell dedifferentiation.

Plant regulatory noncoding RNAs (ncRNAs) have emerged as key modulators of gene expression during callus induction. Their further study may promote the design of innovative plant tissue culture protocols. The use of plants by humans has recently taken on a new and expanding insight due to the advent of genetic engineering technologies. In this context, callus cultures have shown remarkable potential for synthesizing valuable biomolecules, crop improvement, plant micropropagation, and biodiversity preservation. A crucial stage in callus production is the conversion of somatic cells into totipotent cells; compelling evidence indicates that stress factors, transcriptional regulators, and plant hormones can trigger this biological event. Besides, posttranscriptional regulators of gene expression might be essential participants in callus induction. However, research related to the analysis of noncoding RNAs (ncRNAs) that modulate callogenesis and plant cell dedifferentiation in vitro is still at an early stage. During the last decade, some relevant studies have enlightened the fact that different classes of ncRNAs, such as microRNAs (miRNAs), small interfering RNAs (siRNAs), and long noncoding RNAs (lncRNAs) are implicated in plant cell dedifferentiation through regulating the expression levels of diverse gene targets. Hence, understanding the molecular relevance of these ncRNAs in the aforesaid biological processes might represent a promising source of new biotechnological approaches for callus culture and plant improvement. In this current work, we review the experimental evidence regarding the prospective roles of ncRNAs in callus induction and plant cell dedifferentiation to promote this field of study.