Grafting as a tool for tolerance of abiotic stress

Abstract

Grafting of annual fruit crops is expected to expand in the coming decades as an alternative means to overcome abiotic stresses such as suboptimal and/or supra-optimal temperatures, drought, salinity, nutrient stress, heavy-metal contamination, adverse soil pH and flooding. Grafting on to tolerant and suitable rootstocks enables greater adaptability of elite scion varieties to adverse environments. The responses of grafted plants to abiotic stress conditions depend on the scion as well as the rootstock genotype and the scion × rootstock interactions. The anatomical, physiological and agronomical processes implicated in the abiotic stress tolerance of grafted plants have received much attention. However, the molecular aspects involved remain relatively unknown. ‘Omic’ approaches, suchas genomics, metabolomics, xylomics and proteomics, are needed to clarify the functions of many genes, proteins and metabolite networks involved in root-toshoot interactions of grafted plants in response to unfavourable soil and environmental conditions. Unravelling the root-based mechanisms responsible for the higher scion performance of grafted plants will not only contribute to a better understanding of their mode of action but also improve their breeding efficiency