Molecular Evidences for the Interactions of Auxin, Gibberellin, and Cytokinin in Bent Peduncle Phenomenon in Rose (Rosa sp.)

Abstract

In roses (Rosa sp.), peduncle morphology is an important ornamental feature. The common physiological abnormality known as the bent peduncle phenomenon (BPP) seriously decreases the quality of rose flowers and thus the commercial value. Because the molecular mechanisms underlying this condition are poorly understood, we analysed the transcriptional profiles and cellular structures of bent rose peduncles. Numerous differentially expressed genes involved in the auxin, cytokinin, and gibberellin signaling pathways were shown to be associated with bent peduncle. Paraffin sections showed that the cell number on the upper sides of bent peduncles was increased, while the cells on the lower sides were larger than those in normal peduncles. We also investigated the large, deformed sepals that usually accompany BPP and found increased expression level of some auxin-responsive genes and decreased expression level of genes that are involved in cytokinin and gibberellin synthesis in these sepals. Furthermore, removal of the deformed sepals partially relieved BPP. In summary, our findings suggest that auxin, cytokinin, and gibberellin all influence the development of BPP by regulating cell division and expansion. To effectively reduce BPP in roses, more efforts need to be devoted to the molecular regulation of gibberellins and cytokinins in addition to that of auxin.

Insights into the Hormone-Regulating Mechanism of Adventitious Root Formation in Softwood Cuttings of Cyclocarya paliurus and Optimization of the Hormone-Based Formula for Promoting Rooting

“…For instance, the key transcription factors of auxin, CK, GA, and ABA signaling have been well investigated, and it has been suggested that AR formation in some plants is controlled by coordinated hormonal regulation via a series of complex interactions [21,27]. Auxin, as the core of the crossregulatory network [29], has confirmed that interactions of auxin signaling with CK, GA, and ABA exist, as seen in the studies of Arabidopsis roots [15,32,34], but the phytohormone regulation network in woody plants, such as C. paliurus, is still poorly understood during AR formation. In this study, our objectives were as follows: (1) figure out the best hormonebased formulas to promote AR formation in softwood cuttings of C. paliurus; (2) explore the relationship between the endogenous hormone dynamic and the AR formation of C. paliurus softwood cuttings; and (3) screen the key genes involved in hormonal regulation and construct an auxin cross-regulatory network.…”

“…It is reported that phytohormones regulate the AR formation process by providing inherent signaling for determining cell fates and responding to stresses [17]. In recent years, some studies tried to reveal the phytohormone regulatory network using transcriptomic analyses and RNA-seq technology, especially focusing on the key regulatory components involved in the hormone signaling pathway [17,32,33]. For instance, the key transcription factors of auxin, CK, GA, and ABA signaling have been well investigated, and it has been suggested that AR formation in some plants is controlled by coordinated hormonal regulation via a series of complex interactions [21,27].…”

Integrated Transcriptome and Metabolome Analysis Reveals an Essential Role for Auxin in Hypocotyl Elongation during End-of-Day Far-Red Treatment of Cucurbita moschata (Duch. Ex Lam.)

“…Hypocotyls were fixed in FAA (3.7% formaldehyde, 5% acetic acid, and 50% ethanol by volume) for 24 h under vacuum, then dehydrated in an ethanol series (70, 80, and 90%) and processed as described previously [22]. Wax blocks were sectioned at 10 µm.…”

Integrated Analysis of the Transcriptome and Metabolomics Reveals an Essential Role for Auxin in Hypocotyl Elongation During End-of-Day Far-Red Treatment of Cucurbita Moschata

“…xative for more than 24 hours under vacuum. The xed tissues were then dehydrated in an ethanol series (70, 80, and 90%) and processed as described [68]. Wax blocks were sectioned at 10 µm.…”