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Effects of cold and methyl jasmonate on the expression of miRNAs and target genes in response to vernalization in two wheat cultivars (Triticum aestivum L.)

Nooshin Ashoori, Reza Fotovat, Ehsan Mohsenifard

Abstract

Wheat undergoes significant physiological changes during winter, driven by processes such as cold acclimation and vernalization, which are regulated by gene expression and phytohormones. This study investigates the effects of methyl jasmonate (MeJA) and cold treatments on the expression of three specific miRNAs and their target genes in Baz spring wheat and Norstar winter wheat, using qRT-PCR analysis. The objective of this study is to examine the impact of MeJA on vernalization and cold adaptation in these genotypes. Results show that MeJA has no significant impact on vernalization and acclimation in Baz, while it decreases these traits in Norstar. Additionally, the expression of miRNAs in Norstar was significantly reduced after a 2-day cold treatment, particularly for miR156, and further reduced after 14 days for miR172 and miR319. In contrast, Baz showed varied gene expression responses, with an increase in miRNA levels after the 14-day cold treatment. MeJA combined with a 2-day cold treatment suppressed the expression of SPL, AP2, and MYB3 target genes, with the most pronounced suppression seen in SPL. However, AP2 was induced after 14-day cold treatment in both cultivars. The study highlights an inverse relationship between miRNAs and their target genes under vernalization conditions, underscoring the complex regulatory interactions between genotype, miRNAs, and their target genes. Therefore, these findings provide new insights into how MeJA and cold treatments modulate miRNA and gene expression, enhancing our understanding of wheat's adaptive response mechanisms.

FP24130  Accepted 18 February 2025

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