KNUCKLES’ Role in Flower Clock; This Tiny Multi-Functional Protein Helps Complete Floral Development Properly at the Right Time

The Nara Institute of Science and Technology and Nanjing University have recently discovered that a tiny multifunctional protein called KNUCKLES or KNU benefits flowers, particularly in their development.

As specified in a Phys.org report, this protein helps a flower complete its development in both the right and timely manner.

KNU halts a feedback loop between a pair of genes, performing various roles to enable the flower's proper formation of reproductive organs within a short period. This study will be helpful for genetic research of food crops, as well as the production of food worldwide.

How flowers are forming properly within a limited period of time has remained a mystery, at least until the present. Scientists from China and Japan have discovered the manner a multi-tasking protein is helping flowers to develop as expected.

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Small Protein Yet with Multiple Functions

In the study, Robust control of floral meristem determinacy by position-specific multiple functions of KNUCKLES, published in Proceedings of the National Academy of Sciences, researchers from Nanjing University and Nara Institute of Science and Technology have found that a tiny protein is playing multiple roles to guarantee that floral reproductive organs are properly formed within a short span of time.

Flowers are developing from floral meristems, differentiating to yield the sepals, carpels, and stamens. These floral organs' proper development depends on meristem development being completed within a specific timeframe.

In the flower development's early stages, stem cells offer the cell source for the formation of the floral organs. Meanwhile, in floral meristems, stem cell activities are retained through a feedback loop between a gene that identifies floral stem cells called WUSCHEL or WUS, and a stem cell mark gene stimulated and sustained by WUS called CLAVATA3 or CLV3.

How KNU Works

According to Erlei Shang, lead author of the study, KNUCKLES, the small protein represses WUS directly, which results in the completion of floral stem cell activity in a timely manner.

What is not completely understood, Shag continued, is how the strong floral stem cell activity completes within a limited timeframe to guarantee carpel development.

This team's research showed that in Arabidopsis thaliana, explained Toshiro Ito, the study's senior author, the said protein could totally deactivate the robust floral meristems at a certain floral stage to the numerous functions carried out by KNU through its position-specific functions.

As specified in a similar Native News Post report, KNUCKLES both represses and silence WUS, and directly represses CLV3 AND CLV1, a gene encoding a receptor for the CLV3 peptide.

As a result, KNU takes out the CLV3-WUS feedback loop through transcriptional and epigenetic mechanisms, which do not alter the fundamental DNA sequences.

This small protein also interacts physically with the WUS protein, inhibiting WUS from sustaining CLV3, distracting interactions needed for the maintenance of floral meristems.

Study Findings

Bo Sun, the study's corresponding author explained, their findings reveal a regulatory pathway from which KNU, which is described in the National Library of Medicine, is playing a vital role in supporting the floral meristem development's completion within a short timeframe, which guarantees that flower reproductive organs are properly formed.

These study findings will be helpful for genetic research on food crop species like tice, maize, and tomatoes. More so, an understanding of the floral meristem termination mechanism found in this particular research will be beneficial to crop yields for global food production.

Related information about floral development is shown on Molecule's YouTube video below: