Transcriptome Analysis Reveals the Senescence Process Controlling the Flower Opening and Closure Rhythm in the Waterlilies (Nymphaea L.)

Abstract

Most waterlily flowers open at dawn and close after noon usually for three to four days, and thereafter wilt. The short lifespan of flowers restricts the development of the flower postharvest industry. The termination of flower movements is a key event during flower aging process. However, it is still unclear when the senescence process initiates and how it terminates the movement rhythm. In this study, we observed that the opening diameter of flowers was the smallest on the fourth (last) flowering day. Subsequent transcriptome profiles generated from petals at different flowering stages showed that the multiple signaling pathways were activated at the last closure stage (Time 3, T3) of the flowers, including Ca2+, reactive oxygen species and far red light signaling pathways, as well as auxin, ethylene and jasmonic acid signaling pathways. Moreover, In terms of cell metabolism regulation, the genes related to hydrolase (protease, phospholipase, nuclease) were upregulated at T3 stage, indicating that petals entered the senescence stage at that time; and the genes related to water transport and cell wall modification were also differentially regulated at T3 stage, which would affect the ability of cell expand and contract, and eventually lead to petal not open after the fourth day. Collectively, our data provided a new insight into the termination of flower opening in the waterlilies, and a global understanding of the senescence process of those opening-closure rhythm flowers.

Transcriptome Analysis Revealing the Interaction of Abscisic Acid and Cell Wall Modifications during the Flower Opening and Closing Process of Nymphaea lotus

“…The above pathways were also discussed in our laboratory’s previous studies on N . ‘Blue Bird’ that open during the day (T1) and close at night (T2) [ 24 ]. However, the differences and similarities between the waterlilies that open at night and those that open during the day in terms of the above pathways are not known at present.…”

“…In order to verify the results of RNA-Seq, 13 unigenes were selected for real-time fluorescence quantitative PCR (qRT-PCR) analysis, and the primer sequences designed by NCBI were cited as shown in Supplementary Table S1 . Actin11 was selected as the internal reference [ 24 ]. The real-time ReLRT PCR experiment was carried out on the instrument of Applied Biosystems Quantum Studio 3 and 5 System (Thermo Fisher Scientific, Waltham, MA, USA).…”

“…Abscisic acid can regulate the formation of the secondary cell wall and the accumulation of lignin, thus affecting the cell wall [ 23 ]. As for the effects of hormone and cell wall modification on the flowering motility rhythm of waterlilies, the effects of auxin and gibberellin on cell wall modification have been mentioned [ 10 , 24 ], effects which in turn affect the opening and closing of flowers. The mechanism of hormonal regulation and cell wall modification affecting the flowering of night-open waterlilies is not yet known, and the differences between the signal transduction and substance metabolism pathways affecting petal movement and day-open waterlilies are also poorly understood.…”

Cherry Blossom Forecast Based on Transcriptome of Floral Organs Approaching Blooming in the Flowering Cherry (Cerasus × yedoensis) Cultivar ‘Somei-Yoshino’

“…Owing to several recent knowledge on the flower opening ( van Doorn and Kamdee, 2014 ; Chen et al, 2020 ; Zhao et al, 2020 ; Cheng et al, 2021 ; Li et al, 2021 ; Sun et al, 2021 ), we hypothesized that transcription factors would be activated by phytohormone induced by environmental stimuli and regulate transporters and aquaporins to expand floral organ cells associating cell wall organization. Among them, we assumed that cell wall organization might be a direct mechanical driver for petal movement to open flowers.…”

Insights into Adaptive Regulation of the Leaf-Petiole System: Strategies for Survival of Water Lily Plants under Salt Stress

“…The water lily is a perennial floating plant of the Nymphaeaceae family, which is one of the most ancient angiosperm lineages [ 1 ]. Water lilies are famous for their colorful flowers and strong fragrance [ 2 , 3 ]. The water lily flower is also widely used for essential oil extraction and its medicinal properties [ 4 , 5 ].…”