Despite the evolution that causes a large number of differences, many plants work the same way. Now a new study has revealed the different genetic strategies that different types of flower species use to achieve the same status quo.
In flowering plants, stem cells are crucial for survival. Influenced by environmental factors, stem cells determine how and when a plant will grow. Whether a plant needs deep roots, higher stems or more leaves and flowers, it is the stem cells that produce new cells for the job.
That is also why having too many or too few stem cells can disrupt the growth of a plant.
Responsible for all this is a "core genetic circuit that is found in all flowering plants," says CSHL Professor and HHMI researcher Zach Lippman.
Published in a paper in Natural genetics, Lippman and CSHL Professor David Jackson describe the genetic mechanisms that ensure that "a deeply conserved stem circuit" retains some function even if defects occur in a signal protein called CLV3 and the receptor with which it interacts, CLV1.
"Those players are crucial to ensure that a plant has the right number of stem cells throughout life, and we discovered that there are backup systems that pop up when these players are affected by accidental mutations," Lippman explains.
The researchers have found that while stem cell cycles are essential for flowering plants, the genetic backup systems can vary drastically from plant to plant.
For example, if the gene that produces CLV3 is disrupted by a mutation in a tomato, a related gene will take care of it. However, the Jackson team discovered that in the case of corn, two genes work in parallel to produce the essential signal protein.
"I like to compare it to a rowing boat," Lippman adds. "In tomato there are two people who can row but only one row. But if the main rudder injures his arm, the second person can pick up the oars. In corn they both row, although not necessarily with equal effort and in Arabidopsis [rockcress] you have one main rose supported by seven, eight or nine other rowers in the boat; and it looks like only one has a full strap. The rest uses only very small paddles. "
"We were surprised to see such big differences," Jackson says, "but in retrospect it reveals the power of evolution in finding new ways to protect critical development circles."
According to Jackson, Lippman and their colleagues, understanding these species-specific strategies for protecting important genetic interactions will be essential for achieving "intelligent crop design" and using genome editing to improve agricultural productivity and sustainability.
Material supplied by Cold Spring Harbor Laboratory. Note: Content can be edited for style and length.