Profiling of MicroRNAs Involved in Mepiquat Chloride-Mediated Inhibition of Internode Elongation in Cotton (Gossypium hirsutum L.) Seedlings

Abstract

Mepiquat chloride (MC) is the most important plant growth retardant that is widely used in cotton (Gossypium hirsutum L.) production to suppress excessive vegetative growth and improve plant architecture. MicroRNAs (miRNAs) are important gene expression regulators that control plant growth and development. However, miRNA-mediated post-transcriptional regulation in MC-induced growth inhibition remains unclear. In this study, the dynamic expression profiles of miRNAs responsive to MC in cotton internodes were investigated. A total of 508 known miRNAs belonging to 197 families and five novel miRNAs were identified. Among them, 104 miRNAs were differentially expressed at 48, 72, or 96 h post MC treatment compared with the control (0 h); majority of them were highly conserved miRNAs. The number of differentially expressed miRNAs increased with time after treatment. The expression of 14 known miRNAs was continuously suppressed, whereas 12 known miRNAs and one novel miRNA were continuously induced by MC. The expression patterns of the nine differentially expressed miRNAs were verified using qRT-PCR. The targets of the known and novel miRNAs were predicted. Four conserved and six novel targets were validated using the RLM-5′ RACE assay. This study revealed that miRNAs play crucial regulatory roles in the MC-induced inhibition of internode elongation. It can improve our understanding of post-transcriptional gene regulation in MC-mediated growth inhibition and could potentially facilitate the breeding of dwarf cotton.

Enhance Growth and Flower Quality of Chrysanthemum indicum L. with Application of Plant Growth Retardants

“…Altogether it can be concluded that PD treatment has the highest effect on internodes length; these retardant plays and important role on blocking gibberellins biosynthesis, which is the key product for cell elongation, and because of this effect internodes length are inhibited. In other studies, it was also reported that plant growth regulators can inhibit internodes growth in Gossypium hirsutum L. [53,54], Bougainvillea [55], Vigna radiata L. [56] and on Zinnia elegans [57].…”

Genome-Wide Identification and Characterization of miRNAs and Natural Antisense Transcripts Show the Complexity of Gene Regulatory Networks for Secondary Metabolism in Aristolochia contorta

“…MiRNA targets were computationally predicted using psRNATarget [ 47 ] with the default parameters. The expression level of each identified miRNA was calculated as transcripts per million (TPM) using the formula: mapped read count/total reads × 1,000,000 [ 71 ]. To assess the expression changes between tissues, three biological replicates were pooled based on the mean TPM values.…”

Different Concentrations of Chemical Topping Agents Affect Cotton Yield and Quality by Regulating Plant Architecture

“…The coordination of the cotton source-sink relationship is not only a material relationship, but plant hormones may also be an important information regulation system [43]. The mechanism of DPC inhibiting the apical dominance of cotton is that it acts as an inhibitor of gibberellin (GA) and inhibits fruit branch elongation and plant height growth by reducing its own GA3 content in cotton tissue [44]. Specifically, it retards vegetative growth by inhibiting the activity of gibberellin involved in cell elongation, which inhibits the signaling pathways and disturbs GA homeostasis by upregulating site-specific genes that ultimately result in keeping the plant stature shorter [45].…”