Plant grafting:Molecular mechanisms and applications

People have grafted plants since antiquity for propagation,to increase yields,and to improve stress tolerance.This cutting and joining of tissues activates an incredible regenerative ability as different plants fuse and grow as one.For over a hundred years,people have studied the scientific basis for how plants graft.Today,new techniques and a deepening knowledge of the molecular basis for graft formation have allowed a range of previously ungraftable combinations to emerge.Here,we review recent developments in our understanding of graft formation,including the attachment and vascular formation steps.We analyze why plants graft and how biotic and abiotic factors influence successful grafting.We also discuss the ability and inability of plants to graft,and how grafting has transformed both horticulture and fundamental plant science.As our knowledge about plant grafting improves,new combinations and techniques will emerge to allow an expanded use of grafting for horticultural applications and to address fundamental research questions.

The regeneration factors ERF114 and ERF115 regulate auxin-mediated lateral root development in response to mechanical cues

Plants show an unparalleled regenerative capacity,allowing them to survive severe stress conditions,such as injury,herbivory attack,and harsh weather conditions.This potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant bodies.Despite the intertwined nature of development and regeneration,common upstream cues and signaling mechanisms are largely unknown.Here,we demonstrate that in addition to being activators of regeneration,ETHYLENE RESPONSE FACTOR 114(ERF114)and ERF115 govern developmental growth in the absence of wounding or injury.Increased ERF114 and ERF115 activity enhances auxin sensitivity,which is correlated with enhanced xylem maturation and lateral root formation,whereas their knockout results in a decrease in lateral roots.Moreover,we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions.Antagonistically,cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions.Taken together,our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114-and ERF115-mediated auxin signaling.