Circadian clock regulates unique concentric ring of blooming optimising pollinator
According to a recent research by plant scientists at the University of California, David an internal circadian clock regulates the unique concentric rings of blooming in sunflowers, optimising pollinator visits.
https://elifesciences.org/reviewed-preprints/80984
The article was released on January 13 2023 in eLife.
The crown of a sunflower is composed of several small florets. Since sunflowers develop in a spiral pattern from the centre to the edge, the youngest florets are located in the centre of the flower face and the most developed ones are located at the edges.
A single floret blooms over the course of a few days. The male flower portion opens on the first day and releases pollen on the second day, the female stigma opens to accept pollen.
A ring of female flower is always outside the earlier-stage, pollen bearing male flowers as a result of some kind fo coordination between the florets that causes them to open in centric rings starting at the edge and progressing inward on succeeding days.
According to lead author Stacey Harmer, professor of plant biology at the University of California, Davis College of Biological Sciences, pollinating bees often land on the ray petals around a sunflower head and go toward the centre.
In other words, after walking over the female florets, they will pick up pollen and carry it to another flower head.
How the spiral pattern of florets transforms into concentric rings of blooming
In order to comprehend how the spiral pattern o florets transforms into concentric ring of blooming, Harmer and postdoctoral researcher Carine Marshall conducted a study.
The circadian rhythms that govern how developing sunflowers track the light during the day were previously proven by Harmer’s group. A plant or animal’s internal circadian clock operates on a cycle of around 24 hours, allowing for the activation of various genes at various times of the day.
The internal clock remains in line with the real daytime thanks to natural day/night cycles. Resetting the clock involve varying the period of daylight or darkness. Continuous light completely throws off the clock in sunflower.
A time lapse film
The scientists recorded time lapse recordings of sunflowers growing under various temperature or light conditions. They discovered that the plant’s circadian clock regulates the floret’s opening.
Florets did not open in concentric rings when the clock was broken by plants growing in continuous light, instead they merely opened according to age, beginning at the periphery and advancing to the centre in a continuous gradient.
When cultivated with a broken clock, plants attracted less pollinators than regular sunflowers when they were placed outside. We believe that their ability to collaborate in this way that need it will be more crucial as farmers adjust to a changing environment, according to Hamer.
Breeders will be able to create cultivars that blossoms at the best times of day to encourage pollination, despite climate change and dwindling insect numbers, she added, if they understand how the circadian clock and the environment impact flowering.
Source: elifesciences
