Improving early plant growth in sweet corn by engineering the soil microbiome

在加拿大，甜玉米是种植最广泛的蔬菜作物，在所有省份都有种植。在加拿大种植甜玉米面临的挑战之一是，生长季节短，必须在室外温度较低的春季种植甜玉米。这些低温降低了种子的发芽和生长速度，最终导致植株体积小，产量低。顺带一提的是，早熟的玉米幼苗耐寒性更好，开花更早，干生物量更多，产量更高。由于这些原因，快速的早期生长是加拿大玉米种植者高度追捧的农艺性状。一种有可能满足这一需求的方法类似于人类肠道微生物群的益生菌补充剂，其中将特定的植物生长促进微生物引入植物微生物群。使用这种方法，温室和田间种植的玉米的早期生长得到了改善。然而，只有很少的研究是针对甜玉米进行的，特别是在加拿大。该项目的主要目的是改善温室和大田种植的加拿大甜玉米的早期甜生长和促进早期开花。为此，我们将评估在引入由INRS-CAFSB的Yergeau实验室分离的不同微生物物种后，甜玉米生长的早期和开花时间的变化。根据初步数据，其中13个分离株促进了小麦和番茄幼苗的早期生长。这些试验将在我们的工业合作伙伴Agro-100（加拿大领先的肥料供应商）提供的温室以及INRS实验田和一个农业现场进行。使这些微生物促进植物生长的潜在机制也将在生化和遗传水平上进行研究。最有希望的微生物将由我们的工业合作伙伴开发成商业产品，并在全国范围内分发给加拿大农民使用。

In Canada, sweet corn is the most widely planted vegetable crop that is grown in all provinces. One of the challenges of growing sweet corn in Canada is that the short growing season necessitates planting sweet corn in the spring when outdoor temperatures are low. These low temperatures reduce germination and growth rates, ultimately leading to small plants with low yields. Incidentally, corn seedlings that undergo rapid early growth have improved cold tolerance, flower earlier, and have more dry biomass and higher yields. For these reasons, rapid early growth is a highly sought-after agronomic trait for Canadian corn farmers. An approach that has the potential to meet this demand is similar to probiotic supplements for the human gut microbiome, in which specific plant growth-promoting microbes are introduced to the plant microbiome. Using this approach, early growth has been improved in corn grown in greenhouses and fields. However, only a handful of these studies have been undertaken on sweet corn, and more specifically in Canada. The main objective of this project is to improve early sweet growth and promote earlier flowering in greenhouse and field-grown Canadian sweet corn. To do so we will assess how early sweet corn growth and time to flowering changes after we introduce different microbial species isolated by the Yergeau lab at INRS-CAFSB. Based on preliminary data, 13 of these isolates increased early plant growth in wheat and tomato seedlings. These experiments will be carried out in a greenhouse provided by our industrial partner Agro-100, a leading Canadian supplier of fertilizers, as well as at the INRS experimental field and an agricultural field site. The underlying mechanisms that enable these microbes to promote plant growth will also be investigated on a biochemical and genetic level. The microbes that show the most promise will then be developed into commercial products by our industrial partner and distributed nationwide for use by Canadian farmers.