Reduced nighttime transpiration is a relevant breeding target for high water-use efficiency in grapevine.

Increasing water scarcity challenges crop sustainability in many regions. As a consequence, the enhancement of transpiration efficiency (TE)-that is, the biomass produced per unit of water transpired-has become crucial in breeding programs. This could be achieved by reducing plant transpiration through a better closure of the stomatal pores at the leaf surface. However, this strategy generally also lowers growth, as stomatal opening is necessary for the capture of atmospheric CO2 that feeds daytime photosynthesis. Here, we considered the reduction in transpiration rate at night (En) as a possible strategy to limit water use without altering growth. For this purpose, we carried out a genetic analysis for En and TE in grapevine, a major crop in drought-prone areas. Using recently developed phenotyping facilities, potted plants of a cross between Syrah and Grenache cultivars were screened for 2 y under well-watered and moderate soil water deficit scenarios. High genetic variability was found for En under both scenarios and was primarily associated with residual diffusion through the stomata. Five quantitative trait loci (QTLs) were detected that underlay genetic variability in En Interestingly, four of them colocalized with QTLs for TE. Moreover, genotypes with favorable alleles on these common QTLs exhibited reduced En without altered growth. These results demonstrate the interest of breeding grapevine for lower water loss at night and pave the way to breeding other crops with this underexploited trait for higher TE.

Mechanisms underlying photosynthetic acclimation to high temperature are different between Vitis vinifera cv. Syrah and Grenache.

Photosynthesis acclimation to high temperature differs among and within species. Grapevine intra-specific variation in photosynthetic acclimation to elevated temperature has been scarcely assessed. Our objectives were to (i) evaluate the mechanisms underlying long-term acclimation of photosynthesis to elevated temperature in grapevine, and (ii) determine whether these responses are similar among two varieties. A warming experiment with well irrigated Grenache and Syrah field-grown plants was performed during two growing seasons comparing plants exposed at ambient temperature (control) with plants in open-top chambers (heating) that increased mean air temperature between 1.5 and 3.6°C. Photosynthetic acclimation was assessed through the response of net assimilation (An), Rubisco carboxylation rate (Vcmax) and electron transport rate (Jmax), at leaf temperatures from 20 to 40°C. Our results evidenced different mechanisms for photosynthetic acclimation to elevated temperature. Compared with control, Grenache heated increased An, maintaining higher Vcmax and Jmax at temperatures above 35°C. By contrast, Syrah heated and control presented similar values of An, Vcmax and Jmax, evidencing an adjustment of photosynthesis without increasing C assimilation. Both varieties increased the optimum temperature for An, but to a lesser extent when growth temperature was higher. Our study provides evidence that grapevine varieties present different acclimation mechanisms to expected warming.

Seguimiento imagenológico de la mama operada e irradiada / Imaging follow-up of the operated and irradiated breast

El seguimiento de la mama operada e irradiada consta de estudios mamográficos y ecográficos anuales, realizando la primera mamografía a los 6 meses de efectuada la radioterapia. En pacientes con cirugía reconstructiva, el método de imágenes elegido para el seguimiento variará según el tipo de procedimiento quirúrgico que se haya realizado. En pacientes con mutaciones genéticas, el seguimiento debe realizarse con Imagen por Resonancia Magnética (irm) dado el riesgo aumentado de cáncer de mama contralateral. Entre los hallazgos benignos más comunes se encuentran el edema, la necrosis grasa, las distorsiones, las calcificaciones con centro radiolúcido y de hilos de sutura. La mamografía es, en la actualidad, el método de estudio imagenológico ampliamente recomendado en la vigilancia del cáncer de mama y se utiliza para el seguimiento a corto plazo de una enferma de cáncer recientemente tratada con tratamiento quirúrgico conservador de la mama. Sin embargo, la irm es el método que mejor evalúa a la mama operada e irradiada. Posee la mayor sensibilidad para detectar carcinoma mamario primario o debido a recidiva; además, permite el diagnóstico diferencial entre fibrosis y recidiva en la cicatriz y la evaluación de los implantes en las mamas reconstruidas.

The follow-up of the operated and irradiated breast consists about an annual mammographic study and an ultrasound study, doing the first mammography 6 months after radiotherapy was performed. In patients with reconstructive surgery, the imaging method chosen for alternative follow-up depends on the type of surgical procedure that has been performed. In patients with genetic mutations, follow-up should be performed with mri, given the risk of contralateral breast cancer. Among the most common benign findings are edema, fat necrosis, distortions, calcifications with radius centers and suture threads. Mammography is currently the most useful method of study in the surveillance of breast cancer, and is used for the short-term follow-up of a recently treated cancer disease, with conservative surgical treatment of the breast. However, mri is the best diagnostic method for the operated and irradiated breast. It has the highest sensitivity to detect primary breast carcinoma or due to a recurrence, and allows the differential diagnosis between fibrosis and recurrence in the scar and the evaluation of the implants in the reconstructed breasts.