Going Against the Grain

Wheat, a grass that originated in the Middle East, now supplies 20% of the daily calories consumed by the human race. Anthropogenic global heating, however threatens wheat crops and could result in widespread famine (https://www.theguardian.com/environment/2023/jan/07/holy-grail-wheat-gene-discovery-could-feed-our-overheated-world). It would be highly beneficial to make wheat more resilient to elevated temperatures. Wild grasses have a number of genes, making them disease resistent, salt tolerant and protecting them from heat. Wheat, however, has complex genetics. Wheats are polyploid, having multiple sets of chromosomes. Pasta wheat has 2 sets of chromosomes and bread wheat, 3. Both have a stability gene, segregating the different sets of chromosomes, in their genomes and maximising yields. This stability gene, however, also suppresses the exchange of beneficial chromosomes with wild wheat relatives. The John Innes Centre (Norwich) appear to have found a solution to the problem. They have identified the stability gene, designated Zip4.5B. A mutation of Zip4.5B has been produced. This allows the wheat chromosomes to pair correctly (maximising yields) but lacks the ability to block the creation of new variants with beneficial genes from wild grasses. The John Innes Centre intend to trial new varieties of wheat with heat-tolerant genes in Iberia. If these plants can withstand the heat of Iberia, we may still be able to grow wheat, as our planet becomes hotter and drier.