Transcriptomic and biochemical investigations support the role of rootstock-scion interaction in grapevine berry quality.

BACKGROUND: In viticulture, rootstock genotype plays a critical role to improve scion physiology, berry quality and to adapt grapevine (Vitis vinifera L.) to different environmental conditions. This study aimed at investigating the effect of two different rootstocks (1103 Paulsen - P - and Mgt 101-14 - M) in comparison with not grafted plants - NGC - on transcriptome (RNA-seq and small RNA-seq) and chemical composition of berry skin in Pinot noir, and exploring the influence of rootstock-scion interaction on grape quality. Berry samples, collected at veraison and maturity, were investigated at transcriptional and biochemical levels to depict the impact of rootstock on berry maturation. RESULTS: RNA- and miRNA-seq analyses highlighted that, at veraison, the transcriptomes of the berry skin are extremely similar, while variations associated with the different rootstocks become evident at maturity, suggesting a greater diversification at transcriptional level towards the end of the ripening process. In the experimental design, resembling standard agronomic growth conditions, the vines grafted on the two different rootstocks do not show a high degree of diversity. In general, the few genes differentially expressed at veraison were linked to photosynthesis, putatively because of a ripening delay in not grafted vines, while at maturity the differentially expressed genes were mainly involved in the synthesis and transport of phenylpropanoids (e.g. flavonoids), cell wall loosening, and stress response. These results were supported by some differences in berry phenolic composition detected between grafted and not grafted plants, in particular in resveratrol derivatives accumulation. CONCLUSIONS: Transcriptomic and biochemical data demonstrate a stronger impact of 1103 Paulsen rootstock than Mgt 101-14 or not grafted plants on ripening processes related to the secondary metabolite accumulations in berry skin tissue. Interestingly, the MYB14 gene, involved in the feedback regulation of resveratrol biosynthesis was up-regulated in 1103 Paulsen thus supporting a putative greater accumulation of stilbenes in mature berries.

Grape Berry Acclimation to Excessive Solar Irradiance Leads to Repartitioning between Major Flavonoid Groups.

Warm viticulture regions are associated with inferior wines, resulting from the interaction between microclimate and fruit biochemistry. Solar irradiance triggers biosynthetic processes in the fruit and dominates its thermal balance. Therefore, deciphering its impact on fruit metabolism is pivotal to develop strategies for fruit protection and ameliorate its quality traits. Here, we modified light quality and intensity in the fruit-zone and integrated micrometeorology with grape and wine metabolomics, allowing a complete assessment, from field to bottle. We analyzed the dynamics of fruit's adaptation to altered conditions during ripening and constructed temporal-based metabolic networks. Micrometeorological modifications shifted the balance between the major flavonoids, associating increased solar exposure with lower levels of anthocyanins and flavan-3-ols, and higher flavonols. Differences were fixed from 2 weeks postveraison until harvest, suggesting a controlled acclimation response rather than external modulation. Differences in grape composition manifested in the wine and resulted in higher color intensity and improved wine hue under partial shading.

Prenatal diagnosis of sex chromosome aneuploidy: possible reasons for high rates of pregnancy termination.

Sex chromosome aneuploidy (SCA), when detected in amniocentesis, is usually an unexpected result of a test carried out for another purpose. For most SCAs, the prognosis is milder and less predictable than trisomy 21, and therefore parents are faced with a difficult decision regarding the option of pregnancy termination. While studies from Europe and the USA report a declining trend in termination rates for SCA, our local experience is different. During the period 1989-1998, we diagnosed 60 SCA (including mosaics) in 20 106 amniocenteses (0.29%) and 48 (80%) of these pregnancies were terminated, a significantly higher proportion than has been reported in Europe and the USA. The present study shows that the difference between our experience and others' may be related to differences in cultural norms and values. Thirty women were interviewed, of whom 23 terminated and seven continued the pregnancy. Interview analyses showed that the main reason behind the decision to terminate the pregnancy was associated with the parents' fear of non-specific abnormality of the child, and concerns about abnormal sexual development. Although genetic counseling practised in our center aims to be non-directive, 56% of the women reported that the counseling was either directive towards termination, or that they at least felt that the counselor's attitude was pro-termination. Most women (93%) reported themselves as having come to terms with their decision.

Prenatal testing for genetic disorders among Arabs.

Since, at least in the near future, prenatal testing and abortion of affected fetuses will remain the main way of the prevention of genetic diseases, knowledge about the way of its acceptance in different cultures is important. The Israeli population includes two major groups: Jewish and Arabs, but while there is wide experience about the Jewish population and its attitude towards prenatal testing, little is known about the Arab population. This knowledge is particularly important, since genetic disorders are relatively frequent in the Arab world (Teebi and Farag, 1997). From 1992 to 1996, 816 prenatal tests were performed in our department on Arab women [143 chorionic villus sampling (CVS) procedures and 673 amniocenteses]. The indication for an early prenatal test was a high risk for a monogenic disorder in 140 out of the 146 tests performed (143 CVS procedures and three early amniocenteses). In 26 cases, the fetus was found to be affected and early abortion was chosen by the couple in 25 cases (96 per cent). The 670 late prenatal tests were done for various reasons including monogenic disorders (13 per cent), increased risk because of a previous child affected with Down syndrome or a neural tube defect (4.8 per cent), and an increased risk for a chromosomal aberration (78 per cent). In 31 cases of a late prenatal test, the fetus was found to be affected and only 21 couples (70 per cent) opted for an abortion. The major reason for this observation is probably related to religious and cultural factors. Since Arab women do not wish to have prenatal testing for only knowledge or reassurance, these factors should be taken into consideration during pre-amniocentesis counselling.