Plants dont get cancer but they can get

Plants don’t get cancer but they can get tumour-like swellings This tree has a growth called a crown gall caused by a bacterium. Describe what you think might be happening inside the plant to cause the swelling of the tissue.

Inside the gall • The bacteria cause the plant cells to divide, producing a mass of cells that form the gall. • They also cause the cells to make modified amino acids the bacteria can use as a food source but the plant cannot.

Cell cycle • A growing and dividing cell goes through a series of stages called the cell cycle. Mitosis and cell division Interphase Cell growth and synthesis of sub-cellular structures

Mitosis • The cell divides to form two identical cells Amanda Scheliga Flickr CC 2

Inside the gall - natural genetic modification • The bacterium enters the plant through a wound, often where the root and stem join. • It transfers part of its DNA (a loop of DNA called a plasmid) into the plant cell. • The DNA becomes integrated into the plant's chromosome. • The bacterial genes are expressed, producing chemicals that increase cell division causing the mass of cells that make up the gall to form.

Bacteria also hijack metabolism • Some of the bacterial genes code for modified amino acids. They are synthesised by plant cells within the crown gall. • The bacteria use these amino acids as a source of carbon but they cannot be used by the plant itself.

Genetic engineering • Genetic engineers use the bacterium to transfer the gene for a desirable characteristic into a plant’s genome. • Plant crops have been genetically engineered to be resistant to diseases using this method.

Exciting discovery Jennifer Doudna – Jussi Puikkonen/KNAW Jennifer Doubna, an American biochemist, and Emmanuelle Charpentier, a French microbiologist, discovered a new method of genome editing called CRISPR-Cas 9. It is much faster, cheaper and more accurate, allowing genetic material to be added, removed, or altered at particular locations in the genome. See Yourgenome Emmanuelle Charpentier Thor Nielsen / NTNU