Beyond the Genetic Pathways, Flowering Regulation Complexity in Arabidopsis thaliana

Abstract

Flowering is one of the most critical developmental transitions in plants’ life. The irreversible change from the vegetative to the reproductive stage is strictly controlled to ensure the progeny’s success. In Arabidopsis thaliana, seven flowering genetic pathways have been described under specific growth conditions. However, the evidence condensed here suggest that these pathways are tightly interconnected in a complex multilevel regulatory network. In this review, we pursue an integrative approach emphasizing the molecular interactions among the flowering regulatory network components. We also consider that the same regulatory network prevents or induces flowering phase change in response to internal cues modulated by environmental signals. In this sense, we describe how during the vegetative phase of development it is essential to prevent the expression of flowering promoting genes until they are required. Then, we mention flowering regulation under suboptimal growing temperatures, such as those in autumn and winter. We next expose the requirement of endogenous signals in flowering, and finally, the acceleration of this transition by long-day photoperiod and temperature rise signals allowing A. thaliana to bloom in spring and summer seasons. With this approach, we aim to provide an initial systemic view to help the reader integrate this complex developmental process.

Characterization of Phytohormones and Transcriptomic Profiling of the Female and Male Inflorescence Development in Manchurian Walnut (Juglans mandshurica Maxim.)

“…During the process of evolution, plants have gradually evolved sensitivity to different temperatures and light for better adaptation to their environment, thereby mediating transition to flowering [ 15 , 16 ]. In Arabidopsis , a decrease in the ambient temperature (to less than 16 °C) causes delayed flowering activity, while vernalization signaling significantly enhances flowering control [ 17 ]. Additionally, flowering is induced by changes in the ambient temperature in species of Phalaenopsis , and low ambient temperature (less than 26 °C) promotes the flowering process, while the activity can be reversed at elevated ambient temperature [ 18 ].…”

The flowering transition pathways converge into a complex gene regulatory network that underlies the phase changes of the shoot apical meristem in Arabidopsis thaliana

“…But the strongest XAL2 mutants phenotypes were observed under SD photoperiod ( Pérez-Ruiz et al, 2015 ). Since flowering transition relies on developmental and physiological signals under SD conditions ( Wang et al, 2009 ; Quiroz et al, 2021 ), we searched for the role of XAL2 in flowering regulation in response to aging or GA 3 addition.…”

“…In SD, A. thaliana flowering depends on endogenous cues like hormonal and aging signals ( Quiroz et al, 2021 ). The miR156 – SPLs – miR172 – AP2-like module is important for aging developmental changes, and SPL9 and SPL15 positively regulate XAL2 ( Figure 1E ).…”

“…In plants, new organs develop post-embryonically from the apical meristems, where the progeny of a relatively small group of pluripotent stem cells proliferate at the shoot apex and at the root tips ( Kaufmann et al, 2010a ). After a period of vegetative growth, plants respond to a combination of intrinsic signals such as aging, hormones, and carbohydrates, as well as environmental cues like photoperiod and temperature, to trigger the transition to the reproductive phase ( Quiroz et al, 2021 ). Both types of signals are perceived in the leaves and at the shoot apical meristem (SAM), although phase transitions occur at the latter.…”

Functional Redundancy of FLOWERING LOCUS T 3b in Soybean Flowering Time Regulation

“…Furthermore, FT moves to the SAM, where it forms a complex by interacting with FLOWERING LOCUS D (FD) [ 11 , 12 ]. The FT-FD complex induces expression of flowering-related genes, such as SUPPRESSOR OF OVEREXPRESSION OF CO 1 ( SOC1 ), FRUITFULL ( FUL ), and LEAFY ( LFY ), and finally initiates the floral meristem identity gene APETALA1 ( AP1 ) to stimulate flowering [ 11 , 13 , 14 , 15 , 16 ]. Likewise, in rice, the FT homolog protein Heading date 3a (Hd3a) interacts with the FD homolog OsFD1 in the SAM, assisted by 14-3-3 proteins [ 17 ].…”