Year: 2022

REPRESSION PATHWAYS. "The predominance of the different pathways changes with the developmental state of the plant. Early on in the life cycle of the plant flowering is actively repressed to enable the plant to grow sufficiently large to be able to support the development of flowers, fruits and seeds. As the plant develops this repression is gradually lifted by what have been termed floral-enabling pathways such as the vernalization and autonomous pathways." https://lnkd.in/d_f7kfY View in LinkedIn

ACTIVATION PATHWAYS. "In certain environments there is also activation of floral-promotion pathways such as the photoperiodic, gibberellin (GA), ambient temperature and light-quality pathways. At some stage the point is reached when promotion is greater than repression and the flowering transition occurs.' https://lnkd.in/d_f7kfY View in LinkedIn

PATHWAY INTEGRATORS. "All the different flowering pathways converge on a small group of genes called floral-pathway integrators. These genes are FLOWERING LOCUS T (FT), LEAFY (LFY) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), and they are responsible for the activation of the floral meristem identity genes that direct floral organ formation." https://lnkd.in/d_f7kfY View in LinkedIn

PATHWAY CROSSROADS. "Expression of the floral-integrator genes is actively repressed by the floral inhibitor FLOWERING LOCUS C (FLC). Consequently flowering is prevented until this repression is lifted by the floral-enabling pathways, thus allowing activation of the floral-pathway integrators by the floral-promotion pathways." https://lnkd.in/d_f7kfY View in LinkedIn

VERNALIZATION. "Two floral-enabling pathways result in the downregulation of the FLC repressor, the vernalization pathway and the autonomous pathway. Vernalization, resulting from exposure to low temperatures (between 08C and 108C), is a quantitative response and causes progressive downregulation of the FLC gene until the response is saturated after several weeks." https://lnkd.in/d_f7kfY View in LinkedIn

EPIGENETIC SILENCING. "Once the vernalized state has been established it is stable throughout the life of the plant even if returned to warmer temperatures. It is thus mitotically stable through numerous cell divisions indicating that the repression of FLC expression is epigenetic. This epigenetic silencing of FLC is mediated by the VERNALIZATION 1 (VRN1) and VERNALIZATION 2 (VRN2) genes, which are involved in histone methylation and the formation of mitotically stable transcriptionally silent heterochromatin." https://lnkd.in/d_f7kfY View in LinkedIn

PHOTOPERIODS PATHWAY. "Of the floral-promotion pathways, the photoperiodic pathway is probably the best understood. Key elements include a gene named CONSTANS, or CO, which encodes a nuclear protein with two zinc fingers at the amino terminus and a conserved carboxyl-terminal domain, known as the CCT domain for the three plant proteins in which it was identified." https://lnkd.in/d_f7kfY View in LinkedIn

PATHWAY INTERACTIONS. "Floral-promotion pathways do not act in isolation but interact with floral-enabling pathways. The photoperiodic pathway promotes flowering through activation of the floral-integrator genes FT and SOC1, but this is not possible when high levels of FLC are present." https://lnkd.in/d_f7kfY View in LinkedIn

SO ENDS this fragment from nature on the light-synchronized control of plant flowering. The ordered universe meshes with life on earth in great clocks with elaborate genetic control to ensure that sperm meets egg at the correct time in the correct place, and that the mandate of life — reproduction — carries on in glorious wasteful abundance to ensure the survival of the species. If ever there was a single metaphoric cartoon of life, then this is it. View in LinkedIn

ERROR TOLERANCE. "Genes apparently can tolerate a higher percentage of errors than computer code or written text. Sixty-one codons code for only twenty amino acids, so many of the codons are synonymous. Also, proteins can tolerate amino acid substitutions at many positions without losing their function." https://lnkd.in/dH9XaVn View in LinkedIn