RIN enhances plant disease resistance via root exudate-mediated assembly of diseasesuppressive rhizosphere microbiota

The RIPENING-INHIBITOR(RIN)transcriptional factor is a key regulator governing fruit ripening.While RIN also affects other physiological processes,its potential roles in triggering interactions with the rhizosphere microbiome and plant health are unknown.Here we show that RIN affects microbiome-mediated disease resistance via root exudation,leading to recruitment of microbiota that suppress the soil-borne,phytopathogenic Ralstonia solanacearum bacterium.Compared with the wild-type(WT)plant,RIN mutants had different root exudate profiles,which were associated with distinct changes in microbiome composition and diversity.Specifically,the relative abundances of antibiosis-associated genes and pathogensuppressing Actinobacteria(Streptomyces)were clearly lower in the rhizosphere of rin mutants.The composition,diversity,and suppressiveness of rin plant microbiomes could be restored by the application of 3-hydroxyflavone and riboflavin,which were exuded in much lower concentrations by the rin mutant.Interestingly,RIN-mediated effects on root exudates,Actinobacteria,and disease suppression were evident from the seedling stage,indicating that RIN plays a dual role in the early assembly of diseasesuppressive microbiota and late fruit development.Collectively,our work suggests that,while plant disease resistance is a complex trait driven by interactions between the plant,rhizosphere microbiome,and the pathogen,it can be indirectly manipulated using"prebiotic"compounds that promote the recruitment of disease-suppressive microbiota.

Coming of age for the rhizosphere microbiome transplantation

Microbiome transplants have the potential to disrupt agriculture and medicine by transferring the microbial genetic pool(and hence capabilities)from one host to another.Yet,for this technology to become reality,we need to understand the drivers shaping the success of microbiome transplant.We highlight here recent findings by Dr.Gaofei Jiang and colleagues.Using disease suppression as a model function,they highlight the microbiome characteristics making a successful transplant possible.We see this study is a seminal work making microbiome transplant an informed process that will replace the current error-prone trial procedures.We anticipate that the insights may catalyse a paradigm shift in microbiome management in agriculture and medicine.

Rhizosphere immunity: targeting the underground for sustainable plant health management

Managing plant health is a great challenge formodern food production and is further complicated by thelack of common ground between the many disciplinesinvolved in disease control. Here we present the concept ofrhizosphere immunity, in which plant health is consideredas an ecosystem level property emerging from networks ofinteractions between plants, microbiota and the surround-ing soil matrix. These interactions can potentially extendthe innate plant immune system to a point where therhizosphere immunity can fulfil all four core functions ofafull immune system: pathogen prevention, recognition,response and homeostasis. We suggest that consideringplant health from a meta-organism perspective will help indeveloping multidisciplinary pathogen management stra-tegies that focus on steering the whole plant-microbe-soilnetworks instead of individual components. This might beachieved by bringing together the latest discoveries inphytopathology, microbiome research, soil science andagronomy to pave the way toward more sustainable andproductive agriculture.