Mushrooms can't cope with bumps - they turn brown.
Amrah Weijn has discovered genes and compounds that can be used to breed a bruise-resistant mushroom.
PhD student Amrah Weijn discovered that the susceptibility to bruising is partly genetic. She tested 50 different mushroom varieties, including wild varieties. She used a 'bruise test' she had developed herself to determine which varieties were best able to withstand bruising. Then she compared the DNA of the susceptible varieties with that of the robust varieties to find the genes that affect susceptibility.
She also examined the mushroom's metabolism to see which compounds cause the brown colour. She found two aromatic compounds that are converted into melanin, the substance that causes the discoloration, by an enzyme. The two building blocks for melanin, GHB and GDHB, can now serve as markers - the less of these compounds there is, the less the risk of discoloration. This new knowledge has already been used by mushroom companies in crossbreeding experiments. Amrah Weijn obtained her doctorate on 14 June; her supervisor was Harry Wichers, professor of Immune Modulation by Food.