Microbial Activity Key to Healthy Plant Growth
Soil microbes are essential for plant health, aiding nutrient absorption and helping plants resist diseases. The Food and Agriculture Organization of the United Nations notes that managing these bacterial and fungal communities could provide a sustainable means to enhance agricultural productivity.
Yet, a significant challenge remains—many soil microbes stay dormant, and only those that are active can colonize plant roots or live within plant tissues.
A new study from Penn State has found that microbial activity, rather than abundance, plays a key role in determining which microbes successfully colonize plants.
Researchers discovered that microbial activity within plant tissues, known as the endosphere, was ten times higher than in the surrounding soil or rhizosphere—the soil immediately around plant roots. They believe this is because plant tissues supply more nutrients, attracting active microbes. Furthermore, microbes that were active in the rhizosphere had a much greater chance of entering the plant than those that were numerous but inactive.
“There is an enormous diversity of microbes in soils but only a small minority seem to be able to make it into plants,” said Jennifer Harris, the study’s first author and a doctoral candidate in Penn State’s Intercollege Graduate Degree Program in Ecology.
“We saw that there seems to be a couple of families and groups that more commonly make it into the plant, but most soil microbes are dormant, so they must ‘wake up’ and exit dormancy to have the potential to carry out plant-beneficial functions.”
To identify active microbes, the team used BONCAT-bioorthogonal non-canonical amino acid tagging—combined with flow cytometry and genetic sequencing.
“This is the first time BONCAT has been used to study microbes along the gradient from nearby soil to root surface to inside the root,” said study leader Estelle Couradeau.
“This research offers a new way to identify which microbes actually ‘work’ in the soil-plant system by looking at their activity, not just their presence.”
Photo Credit: pexels-jan-kroon