Genetic Analysis of Root-to-Shoot Signaling and Rootstock-Mediated Tolerance to Water Deficit in Tomato

Genes (Basel). 2020 Dec 23;12(1):10. doi: 10.3390/genes12010010.

Abstract

Developing drought-tolerant crops is an important strategy to mitigate climate change impacts. Modulating root system function provides opportunities to improve crop yield under biotic and abiotic stresses. With this aim, a commercial hybrid tomato variety was grafted on a genotyped population of 123 recombinant inbred lines (RILs) derived from Solanumpimpinellifolium, and compared with self- and non-grafted controls, under contrasting watering treatments (100% vs. 70% of crop evapotranspiration). Drought tolerance was genetically analyzed for vegetative and flowering traits, and root xylem sap phytohormone and nutrient composition. Under water deficit, around 25% of RILs conferred larger total shoot dry weight than controls. Reproductive and vegetative traits under water deficit were highly and positively correlated to the shoot water content. This association was genetically supported by linkage of quantitative trait loci (QTL) controlling these traits within four genomic regions. From a total of 83 significant QTLs, most were irrigation-regime specific. The gene contents of 8 out of 12 genomic regions containing 46 QTLs were found significantly enriched at certain GO terms and some candidate genes from diverse gene families were identified. Thus, grafting commercial varieties onto selected rootstocks derived from S.pimpinellifolium provides a viable strategy to enhance drought tolerance in tomato.

Keywords: MAPKKK cascade; QTL analysis; S. pimpinellifolium; candidate genes; cytokinins; drought; manganese; rootstock breeding; transcription factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acclimatization / genetics*
  • Chimera / genetics
  • Chimera / metabolism
  • Crop Production / methods
  • Droughts*
  • Genetic Linkage
  • Genome, Plant
  • Plant Growth Regulators / analysis
  • Plant Roots / chemistry
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Quantitative Trait Loci*
  • Solanum lycopersicum / physiology*
  • Water / metabolism*
  • Xylem / chemistry
  • Xylem / genetics
  • Xylem / metabolism

Substances

  • Plant Growth Regulators
  • Water