Isolation and identification of actinobacteria from plant roots.

Abstract

Listen

Translate article

Coombs and Franco (1) reported their isolation and identification of actinobacteria from surface-sterilized root tissues of wheat plants. They claim that their study reveals a novel plant-microbe interaction. While they recognize that actinobacteria inhabit the rhizospheres of many plant species (2), they failed to recognize that Tokala et al. had previously described the colonization of Pisum sativum root nodules and roots by Streptomyces lydicus WYEC108 (3), a similar plant-microbe interaction that had previously been undescribed. It was shown that P. sativum nodule colonization by Streptomyces is a natural event, based on the finding of actinobacteria colonizing the root nodules of pea plants growing in agricultural fields. It was also shown that S. lydicus WYEC108 hyphal growth penetrated the surface layers of the nodules and that colonization aided nodular assimilation of iron and molybdenum. These findings taken together with those of Coombs and Franco (1) strengthen the argument that plants benefit from harboring actinobacteria within their healthy tissues. While the findings of Coombs and Franco showed culture-dependent evidence of plant-root colonization, previous findings that were not cited in their paper show that colonization of the plant roots of P. sativum is important for the health of the plant in the natural environment.