Compositional and Proteomic Analyses of Genetically Modified Broccoli (Brassica oleracea var. italica) Harboring an Agrobacterial Gene

Abstract

Previously, we showed improved shelf life for agrobacterial isopentenyltransferase (ipt) transgenic broccoli (Brassica oleracea var. italica), with yield comparable to commercial varieties, because of the protection mechanism offered by molecular chaperones and stress-related proteins. Here, we used proximate analysis to examine macronutrients, chemical and mineral constituents as well as anti-nutrient and protein changes of ipt-transgenic broccoli and corresponding controls. We also preliminarily assessed safety in mice. Most aspects were comparable between ipt-transgenic broccoli and controls, except for a significant increase in carbohydrate level and a decrease in magnesium content in ipt-transgenic lines 101, 102 and 103, as compared with non-transgenic controls. In addition, the anti-nutrient glucosinolate content was increased and crude fat content decreased in inbred control 104 and transgenic lines as compared with the parental control, “Green King”. Gel-based proteomics detected more than 50 protein spots specifically found in ipt-transgenic broccoli at harvest and after cooking; one-third of these proteins showed homology to potential allergens that also play an important role in plant defense against stresses and senescence. Mice fed levels of ipt-transgenic broccoli mimicking the 120 g/day of broccoli eaten by a 60-kg human adult showed normal growth and immune function. In conclusion, the compositional and proteomic changes attributed to the transgenic ipt gene did not affect the growth and immune response of mice under the feeding regimes examined.

Expression profiles of glucosinolate biosynthetic genes in turnip (Brassica rapa var. rapa) at different developmental stages and effect of transformed flavin‐containing monooxygenase genes on hairy root glucosinolate content

“…These genes also have not been detected in the genomes of B. rapa ssp . pekinensis and broccoli ( B. oleracea var.italica), so they may be specific to Arabidopsis thaliana . However, their absence clearly does not block the GSL biosynthetic pathway in these Brassica species.…”

DNA Sequencing, Other Omics and Synthetic Biology

“…Likewise, proteomics can be a valuable tool on food safety assessments when evaluating transgenic crops (Gong and Wang 2013), particularly to detect unintended effects caused by plant genetic engineering. For example, the compositional and proteomic changes attributed to a transgene in broccoli did not affect the growth and immune response of mice (Liu et al 2014c).…”

Recent progress in the use of ‘omics technologies in brassicaceous vegetables

“…When the effect of exogenously supplying cytokinin (N 6 -benzylaminopurine) was studied at the proteomic level, Liu et al (2013a) detected only a minor degree of overlap with the transgenic contrast, an observation which was taken to suggest that the molecular basis of the delayed post-harvest senescence induced by exogenous cytokinin differed from that induced by endogenous cytokinin. Of the up-regulated stress response related proteins detected in the transgenic material, 17 proved to be heat-stable following cooking and were therefore considered to represent potential allergens ( Liu et al, 2014a ).…”