Dynamics of miRNA mediated regulation of legume symbiosis. (13th January 2021)

• Record Type: Journal Article
• Authors: Tiwari, Manish; Pandey, Vimal; Singh, Baljinder; Bhatia, Sabhyata
• Is Part Of: Plant, cell and environment. Volume 44:Number 5(2021)
• Page Start: 1279
• Page End: 1291
• Publication Date: 2021-01-13
• Subjects: auxin -- cytokinin -- microarray -- NGS -- rhizobia; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13983
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Symbiotic nitrogen fixation in legume nodules is important in soils with low nitrogen availability. The initiation and sustainability of symbiosis require cellular reprogramming that involves the miRNA‐mediated inhibition or activation of specific nodulation genes. The high‐throughput sequencing of small RNA libraries has identified miRNAs and their targets, which are the major players in the post‐transcriptional gene regulation (PTGS) of the different stages of legume–rhizobia symbiosis ranging from bacterial colonization and organogenesis to symbiotic nitrogen fixation. Here, we present an overview of information obtained from the miRNA libraries from nodulating tissues that have been sequenced to date. The functional analysis of miRNAs has revealed roles in phytohormone homeostasis and spatio‐temporal regulation, as well as the mobility of miRNAs and their functions in shoot to root signalling that affects diverse functions, including bacterial entry, meristem division and differentiation, nitrogen fixation and senescence. Furthermore, small RNA fragments of rhizobial origin repress complementary plant mRNAs. We also consider the roles of miRNAs in determinate or indeterminate nodules. Taken together, this overview confirms that miRNAs are master regulators of the legume–rhizobia symbiosis. Abstract : The present review documents the regulation of legume–rhizobia symbiosis by miRNAs enumerating all the small RNA libraries sequenced till date and the miRNAs characterized for their functional role during this complex process which ranges from bacterial invasion, colonization, cellular reprogramming, nitrogen fixation and senescence. An exhaustive report of miRNA established for the regulation of phytohormone levels, type of nodules, that is, determinate or indeterminate and mobility from shoot to root during symbiosis has been provided. Additionally, rhizobial encoded tRNA derived small RNAs that regulate cross‐kingdom host machinery have also been discussed. This work will allow researchers to address the diversity and specificity of miRNA‐mediated regulation of legume–rhizobia symbiosis.