Changes in rhizosphere bacterial populations brought about by management aid in the management of the pathogen that causes citrus greening disease.

Abstract

The worldwide citrus sector is severely impacted by citrus greening, also known as Huanglongbing or HLB, which is mostly brought on by the bacterial disease Candidatus Liberibacter asiaticus (CLas). By lowering pathogen titre and improving root and soil health, microbial community changes brought on by agricultural management are thought to contribute to HLB resistance. The amount of HLB management is questionable, however, since we don't fully understand how management approaches affect the soil microbiome. Here, we looked at how agricultural management techniques affected the rhizosphere-associated bacterial communities, which in turn reduced CLas titer. Samples of the rhizosphere and roots were taken from two locations in Florida where various management techniques (such as the application of compost, metallized reflecting mulch ground coverings, and microbial inoculations) are now being used to avoid HLB. Amplicon sequencing was used to evaluate management-induced alterations in the rhizosphere bacterial population. The titer of the pathogen CLas in roots was measured using qPCR assays. We also assessed the characteristics of the soil and the activity of microbial enzymes involved in the cycling of soil nutrients. According to our findings, certain management techniques cause changes in the rhizosphere bacterial communities' community structure, which have an adverse effect on the HLB pathogen. Management techniques decreased CLas titer and enhanced soil quality. Furthermore, we discovered that Actinobacteria were often concentrated in the effective treatment areas, indicating that Actinobacteria species may serve as markers for the soil's ability to reduce HLB.