K. radicincitans, a beneficial bacteria that promotes radish growth under field conditions

Abstract

Conserving arable soils is a major challenge in agronomy. Using beneficial native microorganisms such as plant growth-promoting bacteria contributes to sustainability in agricultural systems and helps maintain stable yields and product quality. However, the growth-promoting effects of candidate strains observed in pot trials often disappear under field conditions. Therefore, we studied here the bacterial colonization of Kosakonia radicincitans, a known plant growth-promoting bacteria, and the effect of K. radicincitans on radish. We measured plant growth and glucosinolate profile when plants were grown under glasshouse and field conditions. K. radicincitans cells were applied onto seeds or plants when two leaves had emerged. Our results show an increase of up to 25 % of leaf and tuber weights of inoculated radish plants under glasshouse and field conditions, compared to non-inoculated plants. Glucosinolate contents remained unchanged, except when leaves were sprayed with K. radicincitans. We also found that K. radicincitans suppressed aromatic 2-phenylethyl glucosinolates in leaves. To sum up, we demonstrate for the first time the capability of K. radicincitans to persist and promote plant growth in a member of the Brassicaceae family under field conditions. Therefore, K. radicincitans is a promising candidate for further processing as a growth-promoting product in sustainable agriculture.