The biosynthesis of S-(3-hexan-1-ol)-glutathione (3MH-S-glut) and S-(3-hexan-l-ol)-L-cysteine (3MH-S-cys), which act as flavour precursors in wines, in Vitis vinifera grapes exposed to various environmental stress conditions is reported here. Ultraviolet (UV-C) irradiation, water deficit, and biological stimulation up-regulated 3MH-S-glut and 3MH-S-cys biosynthesis in grape leaves. 3MH-S-glut and 3MH-S-cys contents in grape berries were increased by cold shock, heat shock, UV-C irradiation, and biological stimulation. The results suggest that environmental stress enhances the biosynthesis of both flavour precursors in grapevine. The transcription of VvGST1, VvGST3, VvGST4, and GGT in grapevine exposed to the stress conditions was increased markedly compared with that in control grapevine. Also, UV irradiation increased GST (glutathione S-transferase) and GGT (γ-glutamyl transferase) enzyme activities in grape berries. Recombinant VvGST3 and VvGST4, but not VvGST1, mediated the synthesis of 3MH-S-glut from reduced glutathione and trans-2-hexenal in vitro. The enzymatic mediation of flavour precursor production is a novel function of plant GSTs and may result in the detoxification of damaged grape cells under stress conditions.

HighlightCYP71BE5 from grapevine was identified as a sesquiterpene oxidase capable of transforming α-guaiene to (−)-rotundone, responsible for the characteristic spicy aroma in wines.

The morphology of the root apex was analysed by observation of the anatomy of specimens obtained by apicoectomy in cases of refractory apical periodontitis that did not respond to nonsurgical root canal treatment. Apical ramifications were present in 19 (70%) of the roots, while one were found in the remaining eight (3%) roots. This frequency is far higher than that reported by other investigators, suggesting that there is a close relationship between the anatomical complexity of the root canal and the occurrence of refractory apical periodontitis.

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In this work stress concentration factors, Kt , for a round bar with a circular‐arc or V‐shaped notch are considered on the basis of exact solutions for special cases and accurate numerical results. Then, a set of Kt formulae useful for any shape of notch is proposed. The conclusions can be summarized as follows. (i) For the limiting cases of deep (d) and shallow (s) notches, the body force method is used to calculate the Kt values. Then, the formulae are obtained as Ktd and Kts . (ii) On the one hand, upon comparison of Kt  and Ktd it is found that Kt is nearly equal to Ktd if the notch is deep or blunt. (iii) On the other hand, if the notch is sharp or shallow, Kt is mainly controlled by Kts and the notch depth. (iv) The notch shape is classified into several groups according to the notch radius and notch depth. Then, the least‐squares method is applied for the calculation of Kt /Ktd and Kt /Kts . (v) Finally, a set of convenient formulae is proposed that are useful for any shape of notch in a round test specimen. The formulae give SCFs with <1% error for any shape of notch.