Multi-omics Analyses of Non-GM Tomato Scion Engrafted on GM Rootstocks.

Grafting has been widely applied in agricultural production in order to utilize agriculturally valuable traits. The use of genetically modified (GM) plants for grafting with non-GM crops will soon be implemented to generate chimeric plants (transgrafting)*, and the non-GM edible portions thus obtained could fall outside of the current legal regulations. A number of metabolites and macromolecules are reciprocally exchanged between scion and rootstock, affecting the crop properties as food. Accordingly, the potential risks associated with grafting, particularly those related to transgrafting with GM plants, should be carefully evaluated based on scientific evidence. In this study, we prepared a hetero-transgraft line composed of non-GM tomato scion and GM-tobacco rootstock expressing firefly luciferase. We also prepared a homograft line (both rootstock and scion are from non-GM tomato) and a heterograft line (non-GM tobacco rootstock and non-GM tomato scion). The non-GM tomato fruits were harvested from these grafted lines and subjected to comprehensive characterization by multi-omics analysis. Proteomic analysis detected tobacco-derived proteins from both heterograft and hetero-transgraft lines, suggesting protein transfer from the tobacco rootstock to the tomato fruits. No allergenicity information is available for these two tobacco-derived proteins. The transcript levels of the genes encoding two allergenic tomato intrinsic proteins (Sola l 4.0101 and Sola l 4.0201) decreased in the heterograft and hetero-transgraft lines. Several differences were observed in the metabolic profiles, including α-tomatine and nicotine. The accumulation of tobacco-derived nicotine in the tomato fruits of both heterograft and hetero-transgraft lines indicated that the transfer of unfavorable metabolites from rootstock to scion should be assessed as a food safety concern. Further investigations are needed to clarify whether variable environmental conditions and growth periods may influence the qualities of the non-GM edible parts produced by such transgrafted plants.

Expression and distribution of GABA and GABAB-receptor in the rat adrenal gland.

The inhibitory effects of gamma-aminobutyric acid (GABA) in the central and peripheral nervous systems and the endocrine system are mediated by two different GABA receptors: GABAA-receptor (GABAA-R) and GABAB-receptor (GABAB-R). GABAA-R, but not GABAB-R, has been observed in the rat adrenal gland, where GABA is known to be released. This study sought to determine whether both GABA and GABAB-R are present in the endocrine and neuronal elements of the rat adrenal gland, and to investigate whether GABAB-R may play a role in mediating the effects of GABA in secretory activity of these cells. GABA-immunoreactive nerve fibers were observed in the superficial cortex. Some GABA-immunoreactive nerve fibers were found to be associated with blood vessels. Double-immunostaining revealed GABA-immunoreactive nerve fibers in the cortex were choline acetyltransferase (ChAT)-immunonegative. Some GABA-immunoreactive nerve fibers ran through the cortex toward the medulla. In the medulla, GABA-immunoreactivity was seen in some large ganglion cells, but not in the chromaffin cells. Double-immunostaining also showed GABA-immunoreactive ganglion cells were nitric oxide synthase (NOS)-immunopositive. However, neither immunohistochemistry combined with fluorescent microscopy nor double-immunostaining revealed GABA-immunoreactivity in the noradrenaline cells with blue-white fluorescence or in the adrenaline cells with phenylethanolamine N-methyltransferase (PNMT)-immunoreactivity. Furthermore, GABA-immunoreactive nerve fibers were observed in close contact with ganglion cells, but not chromaffin cells. Double-immunostaining also showed that the GABA-immunoreactive nerve fibers were in close contact with NOS- or neuropeptide tyrosine (NPY)-immunoreactive ganglion cells. A few of the GABA-immunoreactive nerve fibers were ChAT-immunopositive, while most of the GABA-immunoreactive nerve fibers were ChAT-immunonegative. Numerous ChAT-immunoreactive nerve fibers were observed in close contact with the ganglion cells and chromaffin cells in the medulla. The GABAB-R-immunoreactivity was found only in ganglion cells in the medulla and not at all in the cortex. Immunohistochemistry combined with fluorescent microscopy and double-immunostaining showed no GABAB-R-immunoreactivity in noradrenaline cells with blue-white fluorescence or in adrenaline cells with PNMT-immunoreactivity. These immunoreactive ganglion cells were NOS- or NPY-immunopositive on double-immunostaining. These findings suggest that GABA from the intra-adrenal nerve fibers may have an inhibitory effect on the secretory activity of ganglion cells and cortical cells, and on the motility of blood vessels in the rat adrenal gland, mediated by GABA-Rs.

γ-Aminobutyric acid B receptor immunoreactivity in the mouse adrenal medulla.

The present study examined gamma-aminobutyric acid B (GABAB ) receptor, GABA, choline acetyltransferase (ChAT), and neuronal nitric oxide synthase (nNOS) immunoreactivities in the mouse adrenal medulla. GABAB receptor immunoreactivity was seen in numerous chromaffin cells and in a few ganglion cells of the adrenal medulla. By using a formaldehyde-induced fluorescence (FIF) method, GABAB receptor immunoreactivity was observed in numerous adrenaline (A) cells, but not in noradrenaline (NA) cells showing blue-white fluorescence. This suggests that GABAB receptors may be present in the A cells and be related to the secretory activity of A cells but not NA cells in the mouse adrenal medulla. GABAB receptor immunoreactive ganglion cells were shown to be nNOS immunopositive by using a double immunostaining method. Weak GABA immunoreactivity was visible in some chromaffin cells and in the numerous nerve fibers of the medulla. By using the FIF method, weak GABA-immunoreactive chromaffin cells were shown to be in the NA cells showing blue-white fluorescence. GABA-immunoreactive nerve fibers were in dense contact in A cells, but not NA cells. GABA-immunoreactive nerve fibers closely contacted a few ganglion cells. Numerous GABA-immunoreactive nerve fibers in the medulla showed ChAT immunoreactive. This result suggests that GABA and acetylcholine may be released from the same nerve fibers and may have a secretory effect on the A cells of the medulla.