In grapevines, stomatal aperture decreases after a mid‐morning peak during summer days. Afternoon stomatal closure increases in non‐irrigated plants as water limitation progresses, which suggests the involvement of abscisic acid (ABA) in the control of stomatal aperture. The objective of this work was to study the seasonal and diurnal time‐courses of CO2 assimilation rate, leaf conductance, leaf water potential +, and ABA concentration in xylem sap, leaves, flowers and berries in non‐irrigated field‐grown Tempranillo grapevines throughout reproductive development. Leaf decreased throughout fruit development because water availability decreased towards the end of the reproductive cycle. CO2 assimilation rate, leaf conductance and xylem ABA concentration also decreased during the course of the growing season. Combining all measurements xylem ABA was either not correlated, or only slightly correlated, with leaf water status + and daily leaf conductance, respectively. This lack of relationship indicates that xylem ABA during fruit ripening had functions other than provision of a non‐hydraulic signal. On a seasonal basis, xylem ABA concentration measured in non‐irrigated grapevines was well related to berry ABA concentration, especially at the end of fruit development (veraison and harvest).

<p style="text-align: justify;">Cinq polyamines libres, la putrescine, la cadavérine, la nor-spermidine, la spermidine et la spermine, ont été mises en évidence dans les feuilles et les grappes du Cabernet- Sauvignon et de l'Ugni blanc. La spermidine est toujours la polyamine la plus abondante. La cadavérine est faiblement représentée ou absente selon le cépage ou l'organe considéré.</p>

<p style="text-align: justify;">L'acide abscissique (ABA) libre synthétisé par les feuilles pendant leur phase de croissance ne s'accumule pas dans ces organes sous forme libre mais sous forme de <em>β</em>-D-glucopyranose (ABA-GE). Les teneurs en ABA libre des feuilles des cépages étudiés sont inversement proportionnelles à leur surface et pourraient jouer un rôle dans le contrôle de leur croissance. Au cours de la véraison, l'ABA libre est exporté massivement vers les baies qui se comportent donc comme un pôle d'attraction très actif vis-à-vis de ce régulateur de croissance. L'accumulation de l'ABA sous ses deux formes se fait toujours dans un ordre bien déterminé: d'abord dans les pépins, puis dans les péricarpes et enfin dans les feuilles pour l'ABA libre et dans l'ordre inverse pour l'ABA-GE. Ce dernier interviendrait pour inactiver l'ABA libre, assurant ainsi un rôle régulateur. L'accumulation précoce de l'ABA libre dans les feuilles à la suite de différents traitements (suppression des grappes notamment) confirme que l'ABA des baies à la véraison provient des feuilles. Mais les expériences d'isolement de grappes, en présence ou en l'absence des feuilles opposées, montrent que dans ces conditions au moins les baies chlorophylliennes doivent aussi être capables de synthétiser de l'ABA.</p>

Effects of Eutypa lata, the fungal agent of eutypiosis, on polyamine (putrescine (Put), spermidine (Spd), spermine (Spm), diaminopropane (Dap)) and tyramine (Tyr) contents in grapevine leaves were studied to determine the relationship between these components and disease development. The external symptoms of eutypiosis are small and necrotic leaves, which could be observed on only one arm or on two arms of the vine stock. This study was carried out on healthy leaves (S, borne by healthy vine stock), apparently healthy leaves (Aps, borne by one arm without symptoms, whereas the other arm was diseased), and moderately (M. mal.) and strongly (F. mal.) diseased leaves. We analysed free polyamines (free PAs, chlorhydric acid soluble fraction), conjugated polyamines (PAs-fpm, PAs covalently linked to molecules with low molecular mass like hydroxycinnamic acids), and bound polyamines (PAs-mm, covalently linked to macromolecules) in Vitis vinifera L. 'Cabernet sauvignon', a variety sensitive to eutypiosis. In diseased leaves, we noted a decrease of free PAs, PAs-fpm, free Tyr, and Tyr-fpm levels. By contrast, the Dap-fpm level was increased by the disease. Eutypiosis also induced an increase of Spm-mm and Dap-mm levels, whereas the Put-mm and Spd-mm levels were decreased. Free Put, free Spd, PAs-fpm, free Tyr, and Tyr-fpm levels were higher in apparently healthy leaves than in healthy leaves. The PAs-mm levels were slightly affected by eutypiosis in apparently healthy leaves. The specific role of each type of polyamines and tyramine is discussed with regard to the host-parasite relationship.Key words: polyamines, leaf, Eutypa lata, Vitis vinifera.

<p style="text-align: justify;">The levels of free and bound ABA (<em>cis</em>-ABA and <em>cis</em>-ABA-GE) were quantified weekly during the dormancy phase of three years in leaves, in latent buds and in internodes grapevine (<em>Vitis vinifera</em> L. cv. Merlot) by high pressure liquid chromatography (HPLC). An inverse variation between <em>cis</em>-ABA and <em>cis</em>-ABA-GE levels was observed in buds and in internodes during some phases of their development. This result seems suggest a possible interconversion phenomenon between these two ABA forms as described in others organs by some authors. The development of ABA in leaves, in buds and in internodes, showed three successive maximums of <em>cis</em>-ABA. The first maximum was observed in leaves during onset of dormancy, the second maximum in buds during dormancy and the last in internodes during the leaf fall. Maximums of <em>cis</em>-ABA in leaves and in buds are approximatively the some values (around of 150 µg/100 g Dry Weight) whereas in internodes is lower (60 µg/100 g Dry Weight). An inverse variation between <em>cis</em>-ABA of leaves and <em>cis</em>-ABA of buds was observed suggesting that the increase of <em>cis</em>-ABA in buds was caused by the <em>cis</em>-ABA translocation from leaves but also from roots. The removal of leaves on september 1997 during the dormancy phase, before leaf fall period, induced an increase of <em>cis</em>-ABA content in buds and internodes. These results seem suggest that before leaf fall period, ABA of buds and internodes were translocated to leaves. During this same period, the removal of leaves and buds induced a slightly soften of ABA content increase in internodes, that seems indicate that ABA was greatly translocated from roots. During the period of leaf fall, the leaf removal traitment induced a decrease of <em>cis</em>-ABA levels in buds and in internodes while the same traitment associated to buds removal stabilized the ABA levels in internodes. During this period, ABA seems exported from leaves to buds and internodes and the roots don't appear to operate significantly in the development of ABA in these two organs.</p>