Boron (B) is essential for plant growth, however its excess in soil and/or in irrigation water can severely compromise plant growth and yield. The goal of this work was to determine whether grafting onto âArnoldâ, a commercial interspecific hybrid (Solanum lycopersicumÂ ÃÂ S.Â habrochaites) rootstock, which in a previous study was found to be tolerant to salt stress, could improve tomato (S.Â lycopersicum L. âIkramâ) tolerance to excess B, and whether this effect is associated with an exclusion mechanism. Non-grafted, self-grafted and grafted plants were hydroponically grown in a greenhouse with B concentration in the nutrient solution of 0.27 (control), 5, 10 and 15Â mgÂ·lâ1. A transcription analysis was carried out on SlNIP5 and SlBOR1 genes, which encode putative B transporters. Grafting âIkramâ onto âArnoldâ rootstock reduced B concentration in leaf tissue of plants exposed to B concentrations of 10â15Â mgÂ·lâ1. At high B levels, SlNIP5 was down-regulated in all grafting combinations, while SlBOR1 was down-regulated only in the roots of plants grafted onto âArnoldâ. We conclude that grafting the susceptible tomato cultivar âIkramâ onto the commercial rootstock âArnoldâ improved tolerance to excess B by reducing expression of genes encoding for B transporters at the root level, thus partially reducing the root uptake of B and its accumulation in the shoot.
|Titolo:||Grafting response to excess boron and expression analysis of genes coding boron transporters in tomato|
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||1.1 Articolo in rivista|