RhWRKY33 Positively Regulates Onset of Floral Senescence by Responding to Wounding- and Ethylene-Signaling in Rose Plants

Abstract

Rose plants are one of the most important horticultural crops, whose commercial value mainly depends on long-distance transportation, and wounding and ethylene are the main factors leading to their quality decline and accelerated senescence in the process. However, underlying molecular mechanisms of crosstalk between wounding and ethylene in the regulation of flower senescence remain poorly understood. In relation to this, transcriptome analysis was performed on rose flowers subjected to various treatments, including control, wounding, ethylene, and wounding- and ethylene- (EW) dual treatment. A large number of differentially expressed genes (DEGs) were identified, ranging from 2,442 between the ethylene- and control-treated groups to 4,055 between the EW- and control-treated groups. Using weighted gene co-expression network analysis (WGCNA), we identified a hub gene RhWRKY33 (rchiobhmchr5g0071811), accumulated in the nucleus, where it may function as a transcription factor. Moreover, quantitative reverse transcription PCR (RT-qPCR) results showed that the expression of RhWRKY33 was higher in the wounding-, ethylene, and EW-treated petals than in the control-treated petals. We also functionally characterized the RhWRKY33 gene through virus-induced gene silencing (VIGS). The silencing of RhWRKY33 significantly delayed the senescence process in the different treatments (control, wounding, ethylene, and EW). Meanwhile, we found that the effect of RhWRKY33-silenced petals under ethylene and EW dual-treatment were stronger than those under wounding treatment in delaying the petal senescence process, implying that RhWRKY33 is closely involved with ethylene and wounding mediated petal senescence. Overall, the results indicate that RhWRKY33 positively regulates the onset of floral senescence mediated by both ethylene and wounding signaling, but relies heavily on ethylene signaling.

Protein Kinase RhCIPK6 Promotes Petal Senescence in Response to Ethylene in Rose (Rosa Hybrida)

“…Among those we identified, some TF genes have similarities to known genes, such as ANAC092 and WRKY40 , which are linked to senescence and autophagy in Arabidopsis [ 41 , 42 ]. In addition, senescence-related TF genes, including RhWRKY33 and RhHB6 , have been found in rose [ 8 , 18 ]. As for protein kinases, except for a few reports on the regulation of mitogen-activated protein kinases, there is not a lot of amount of data about protein kinases involved in rose plant growth and development [ 43 ].…”

“…Recent studies have revealed that ethylene modulates flower senescence by regulating the expression of some senescence-associated genes in rose. Several transcription factors including RhHB1/6, RhMYB108, RhERF113, and RhWRKY33 were reported to regulate ethylene-induced petal senescence and the expression of RhSAG12 (the rose homolog of SAG12 ) [ 6 , 7 , 17 , 18 ]. However, the molecular mechanism of ethylene-induced flower senescence remains largely unknown.…”

DcWRKY33 promotes petal senescence in carnation (Dianthus caryophyllus L.) by activating genes involved in the biosynthesis of ethylene and abscisic acid and accumulation of reactive oxygen species

“…It has been shown that some WRKY family TFs such as DcWRKY75 participate in the ethylene biosynthesis pathway to mediate and regulate carnation petal senescence (Xu et al., 2021), while the current research on WRKY33 is mainly focused on plant defense responses. A recent study showed that RhWRKY33 is involved in mediating ethylene‐induced petal senescence in rose ( Rosa hybrida ) (Jing et al., 2021). Transcriptome and RT‐qPCR analyses revealed that DcWRKY33 expression was significantly upregulated in ethylene‐treated carnation petals (Figure 1c,d).…”

Transcriptome Analysis Reveals Gene Expression Changes during Repair from Mechanical Wounding in Aquilaria sinensis

“…An understanding of the transcriptome changes during mechanical wounding could contribute to artificially inducing the production of secondary metabolites. One of the important steps in the process of repair from mechanical wounding is the reprogramming of the transcriptome, and it involves several genes including those encoding TFs such as WRKY and AP2 [8][9][10][11]. The 'repair' genes encode proteins that function in signaling, phytohormone regulation, transcription regulation, and the synthesis of secondary metabolites [8].…”