Oct. 27 (UPI) — How do plant cells know how to organize into the proper pattern as new leaves form? New research offers clues.
Scientists have made great progress in detailing the communication among animal cells as they develop and form new tissue, but plants evolved separately from other multicellular organisms. As such, researchers know less about how plant cells organize as they form new structures — like fresh leaves.
New research out of the University of Tübingen’s Center for Plant Molecular Biology suggests plant cells use unique signals called “small RNAs” to mobilize new cells. Previous studies have highlighted the role small RNAs play in triggering defense mechanisms against herbivores and disease, but the latest findings — detailed in the journal Developmental Cell — suggest the signal is also vital to the organization of fresh plant cells.
Small RNA are similar to chemical signals used in animals in that different concentrations can trigger different thresholds, allowing the same basic signal to jumpstart a variety of cellular processes.
“Small RNAs are short molecule chains which perfectly match certain regulatory sections of genetic information in DNA or RNA,” researchers explained in a news release. “They are able to attach themselves there, thereby preventing those particular genes from being read.”
By altering the expression of genes, the chemical signals can dictate the formation and behavior of cells.
To better understand how these chemical signals control leaf formation, researchers supplied new cells with artificial small RNA signals and observed how leaf growth was affected.
“The surprising thing was that the small RNAs were able to produce stable patterns,” plant geneticist Marja Timmermans said. “Unlike the conventional development signals, small RNAs operate in a highly specific way, and they can intervene directly in gene activity.”
Because plant cells are connected by plasma bridges, small RNA can move freely throughout the entire system. And the latest research suggests the signals can perform individualized tasks based on its location, enabling it organize new cell growth and form boundaries — or leaf edges.
“Mobile small RNAs provide a high-performance mechanism for passing on positioning information,” Timmermans said. “They can develop precise development patterns.”