Metabolic Interaction between Tomato Scion and Rootstock under Salt Treatment

Salinity is an increasingly expansive problem limiting plant growth and affecting crop production. Grafting is regarded as a promising tool to improve the resistance to soil salinity. Understanding the mechanisms mediating the rootstock affecting the scion is key to broaden the salinity optimum for crops cultivars. In our experiment, we used tomato (Solanum lycopersicum) cv M82 grafted onto 254 different tomato rootstocks, including wild and commercial races and cherry tomatoes. Salt treatment was applied at a concentration of 200 mM NaCl and plant tissue was collected in consecutive weeks for metabolite profiling, ROS estimation, transcript analysis. Plant height, branches per plant, fresh weight of shoot and fruit were measured at harvest. Of the morphological character, 75%, 54% and 67% of scion grafted onto different rootstocks showed higher plant height, fresh weight of fruit and total fresh weight than M82 self-grafted (control), respectively. 98 % showed fewer branches than control. Compared with control, fruit weight was regarded as the trait with highest CV and standard deviation cross the populations. In contrast, the ratio of fruit weight to total weight was the trait with the lowest CV. PCA analysis revealed that, compared with control, tomato line 20 was mostly affected in fresh weight of fruit and shoot, line 210 was affected mostly in ‘branches per plant’. Metabolite and transcript data are being processed.