"When plant cells grow, they tend to expand considerably along their length while not increasing much in width," said Ying Gu, associate professor of biochemistry and molecular biology and co-funded faculty member in the Institutes of Energy and the Environment at Penn State and lead author of the study. "It is generally thought that microtubules -- structures that form the "skeleton" of the cell -- wrap around the cell like rings on a barrel, restricting growth in width. We wanted to know what regulates growth in the cell's length, and found that the story is more complicated than just rings on a barrel."
The team first confirmed that a protein they had previously identified as important to the creation of cellulose -- the main component of cell walls -- is also important to cell growth. A mutant form of the model species thale cress, Arabidopsis thaliana, without the protein known as "cellulose synthase interactive 1" (CSI1) showed severely reduced growth, even in the presence of a growth hormone. A follow-up test indicated that this reduced growth may be due to changes to the mutant's cell wall.
Whim - Graduate - Students - Test - Plant
"On a whim, one of my graduate students decided to perform a creep test, where plant cells are stretched out under acidic conditions," said Gu. "Acidic conditions usually instigate cell growth, but the mutant lacking CSI1 didn't elongate during the test. This suggested that the issue may be with the cell wall or the cell architecture, which was a surprise."
Plant cell walls are composed of many layers, 10 to 20 in thale...
Wake Up To Breaking News!
A single death is a tragedy, a million deaths is a Government intervention.