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RAPID CONVERSION OF STORES. "In most species, the mobilization of storage carbohydrates and/or the import of sucrose accompanies flower opening. Young petal cells of many species contain considerable amounts of starch which, shortly before opening, is rapidly converted to glucose and fructose." http://jxb.oxfordjournals.org/content/54/389/1801.full View in LinkedIn

TURGOR CHEMISTRY. "Floral movements are based on changes in osmotic pressure in cells that do not elongate, or on differential elongation growth. Both involve an increase in osmotic pressure, followed by water uptake. Prior to opening, osmotic solute levels increased, for example by the conversion of polysaccharides (starch or fructan) to monosaccharides, and/or the uptake of sugars from the apoplast." https://lnkd.in/eTEzGE9 View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend on the topic of flower opening and closing, which is so much more than tubes and pumps and fluid dynamics. The biochemistry, genetics and circadian controls behind these fluid mechanics are where it starts to get interesting. Complex changes in cellular viscosity are caused by a cascade of events from the genes to the osmolytes, which change on a diurnal basis, thus controlling flower opening and closure. View in LinkedIn

QUIRKY HABITS. "The setting of the sun does not always bring about the closure of flowers. Indeed, it can have quite the opposite effect. Nightfall is the cue for many plants to begin reproductive activity. Four-o’clocks (Mirabilis jalapa) earn their common name from the time at which their flowers open, about four o’clock in the afternoon. (The ones in my garden, for some reason, seem to be on Greenwich Mean Time — they don't open until around nine o’clock at night.) Four-o’clocks are pollinated by evening-flying moths that are attracted to the sweet fragrance of the flowers." https://lnkd.in/bgcAj66 View in LinkedIn

RNA DRIVEN. "It appears that all the detailed steps of evolution stored in DNA that are read, transcribed, and translated in every developmental and growth process of each individual cell depend on RNA-mediated processes, in most cases interconnected with other RNAs and their associated protein complexes and functions in a strict hierarchy of temporal and spatial steps." https://lnkd.in/euyhznh View in LinkedIn

CIRCADIAN MOVEMENT. Tribulus cistoides. "Its bright yellow flowers come to life at sunrise and face into the sun. During the day, as the sun appears to move across the sky, the flowers of Tribulus track the sun like little satellite dishes, reorienting themselves so that they always face into the sun. When the sun drops below the horizon, the flowers close. Some species of day-flowering plants can open and close their flowers for several days in succession." https://lnkd.in/bgcAj66 View in LinkedIn

DNA NICHE OFFERED DIVERGENCE. "Protein and DNA invention were a prerequisite for the evolution of divergence and the variety of life because all evolutionary inventions could be stored as evolutionary protocols in this stable storage medium. The information content of the human genome is comparable to an archive of 5000 books with 300 pages each." https://lnkd.in/euyhznh View in LinkedIn

CLOCK FACTORS. "The nyctinastic leaf movement is induced by a pair of leaf-movement factors, and one of each pair is a glucoside. There are two key proteins that are involved in the control of nyctinasty. One is β-glucosidase: a biological clock regulates the activity of β-glucosidase, which deactivates the glucoside-type leaf-movement factor, controlling the balance in the concentrations of the leaf-closing and -opening factors. The other is the specific receptor for each leaf-movement factor." https://lnkd.in/bF4kXPr View in LinkedIn

DNA AS NEW ECOLOGICAL NICHE. "The high density of early RNA life led to competing situations in which it was an advantage to escape into DNA informational storage and protein-based cellular life." https://lnkd.in/euyhznh View in LinkedIn

OPPOSED ACTIONS. "Based on our experiments on these bioactive substances, we found that the circadian rhythmic leaf movement of these plants is initiated by the regulated balance of LOSs and LCSs. The balance of concentration between the two leaf-movement factors (LMFs) is inversed during the day. The glycoside-type LMF is hydrolyzed with β-glucosidase, the activity of which is regulated by the biological clock. The circadian rhythm observed in the leaf movement is introduced by activation of β-glucosidase regulated by the biological clock." (LOSs = leaf opening substances; LCSs = leaf closing substances). https://lnkd.in/eHVDKsZ View in LinkedIn