Bioengineering novel post-harvest traits in Brassica crops

forthcoming

Food security and nutritious diets for all are major challenges for a rapidly growing global population and for healthy aging. To feed the global population in the coming years, the production of agricultural crops has to sharply increase, yet up to 50% of harvested vegetables are currently wasted along the supply chain from growers to retailers to consumers. Food waste also produces greenhouse gases that contribute to climate change and their diminishing nutrition upon storage compromise healthy diets. Especially leafy vegetable crops have relatively short-shelf lives: after harvest they rapidly lose nutritional value, suffer from dehydration, and often end up rotting as diseases strike. Thus, there are urgent public health, net zero and economic needs to improve the post-harvest shelf-lives of vegetables. In our ERC-CoG project UbRegulate, we discovered that post-harvest tissues experience extensive changes in their ability to launch immune responses. Further study showed that after harvest, Brassica crops such as cabbage, broccoli and salad rocket, undergo dramatic cellular changes to cope with post-harvest stresses. These findings demonstrate that post-harvest crops respond differently to their environment compared to unharvested crops. Thus, bioengineering harvest-inducible traits – rather than constitutive traits – to improve post-harvest health and longevity is preferable and avoids deleterious side-effects during the on-soil growth phase. Here, we will provide proof-of-concept that synthetic bioengineering approaches can introduce novel traits specifically in harvested tissues. By using synthetic gene circuits, we will specifically express desirable traits only after harvest to extend the healthy shelf-lives of Brassica crops. Improving post-harvest longevity, quality and health of crops will result in large financial gains, food security and dramatically reduce food waste for growers, retailers and consumers.