miRNAs as key regulators via targeting the phytohormone signaling pathways during somatic embryogenesis of plants

Abstract

Somatic embryogenesis is the regeneration of embryos from the somatic cell via dedifferentiation and redifferentiation without the occurrence of fertilization. A complex network of genes regulates the somatic embryogenesis process. Especially, microRNAs (miRNAs) have emerged as key regulators by affecting phytohormone biosynthesis, transport and signal transduction pathways. miRNAs are small, non-coding small RNA regulatory molecules involved in various developmental processes including somatic embryogenesis. Several types of miRNAs such as miR156, miR157, miR 159, miR 160, miR165, miR166, miR167, miR390, miR393 and miR396 have been reported to intricate in regulating somatic embryogenesis via targeting the phytohormone signaling pathways. Here we review current research progress on the miRNA-mediated regulation involved in somatic embryogenesis via regulating auxin, ethylene, abscisic acid and cytokinin signaling pathways. Further, we also discussed the possible role of other phytohormone signaling pathways such as gibberellins, jasmonates, nitric oxide, polyamines and brassinosteroids. Finally, we conclude by discussing the expression of miRNAs and their targets involved in somatic embryogenesis and possible regulatory mechanisms cross talk with phytohormones during somatic embryogenesis.

The Chemical Environment at Maturation Stage in Pinus spp. Somatic Embryogenesis: Implications in the Polyamine Profile of Somatic Embryos and Morphological Characteristics of the Developed Plantlets

“…Polyamines are considered to be a class of compounds related to cellular proliferation (Bais and Ravishankar, 2002;Jimenez, 2005) and play an important role in the regulation of SE (Silveira et al, 2004;Jin et al, 2020;Sundararajan et al, 2021). Moreover, polyamines (PAs) could be associated with the stress caused in plant cells, protecting them and upregulating stress-related genes (Alcazar et al, 2020;Kielkowska and Adamus, 2021).…”

Small RNAs, Degradome, and Transcriptome Sequencing Provide Insights into Papaya Fruit Ripening Regulated by 1-MCP

“…It was found that miR390 stimulates the production of tasiARFs, which repress the expression of their targets ARF3 and ARF4. There was also positive and negative feedback between ARF2/ARF3/ARF4 and miR390 to regulate lateral root growth [ 54 ]. Two highly expressed miRNAs were selected from the ethylene and auxin pathways, and their target genes were verified.…”

Somatyczna embriogeneza: od odkrycia przez badania do praktycznego wykorzystania.

“…Przeprowadzone analizy polegają głównie na porównaniu zmian w akumulacji miRNA oraz ekspresji genów w kalusie embriogenicznym i nieembriogenicznym lub na różnych etapach SE. Wykorzystując sekwencjonowanie nowej generacji, hybrydyzację northern, analizę bibliotek małych RNA czy mikromacierze, zidentyfikowano aktywność wielu konserwowanych ewolucyjnie rodzin genów MIRNA, charakteryzujących się zmiennym, tkankowo-specyficznym poziomem ekspresji na różnych etapach rozwoju zarodka i wykazano, że miRNA mają wpływ na indukcję SE [109]. Ich kluczową rolę potwierdzono wykorzystując mutanty w genie DICER-LIKE 1, kodującym enzym odpowiedzialny za biosyntezę większości roślinnych miRNA, które to okazały się być niezdolne do formowania somatycznych zarodków na zarodkach zygotycznych standardowo używanych w tym celu u rzodkiewnika [110].…”