Blueberries and other fruits are susceptible to fungi such as gray mold, while sunflowers are highly resistant to these fungi. With this in mind, scientists have now used an extract from discarded sunflower stems to prevent the fruit from growing moldy.
Sunflowers have been known for some time for their resistance to a variety of plant diseases. While sunflower seeds and oil have many uses, the stems are often discarded after harvesting.
Led by Xiaodong Luo and Yun Zhao, scientists at the Chinese Academy of Sciences recently began investigating whether these stems could be a source of antifungal compounds and apply them to harvested fruits. Analysis of extracts from these stems revealed that they contained 17 different types of compounds, known as diterpenoids. Four of them were previously unknown to science.
When tested on the fungus Botrytis cinerea, four of the 17 diterpenes, including two new diterpenes, disrupted the fungus's plasma membrane. This causes its cells to become leaky, making it unable to form the disease we know as gray mold.
The scientists then applied a non-toxic sunflower extract solution to a batch of blueberries, which they then dried and injected with Botrytis spores. In 6 days, 42.9% of the blueberries did not become moldy like other fruits. As research continues, this number will rise.
A paper on the research was recently published in the Journal of Agricultural and Food Chemistry.