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Water scarcity is a serious constraint for agriculture, and global warming and climate change can exacerbate it in many areas. Therefore, sustainable approaches must be implemented to deal with current and future water scarcity scenarios. Genetic and chemical approaches are being applied to manage this limitation and maintain crop yields. In particular, biostimulants obtained from natural sources such as marine algae are promising aids for coping with water deficit stress in agriculture. Here we present a bioprospection study of extracts of the macroalgae Bonnemaisonia hamifera, Galaxaura rugosa, Dasycladus vermicularis, Ulva clathrata, Cystoseira foeniculacea, Cystoseira humilis, Lobophora dagamae, Colpomenia sinuosa and Halopteris scoparia from the north coast of Tenerife, in the Canary Islands. The aqueous extracts of Bonnemaisonia hamifera, Galaxaura rugosa, Dasycladus vermicularis and Cystoseira humilis show biostimulant activity against water deficit stress in tomato seedlings under controlled conditions, providing higher tolerance than the mock-treated control. The Galaxaura rugosa extract showed the highest biostimulant activity against water deficit stress. We demonstrate that this positive effect involves the activation of the abscisic acid (ABA) pathway in Arabidopsis thaliana (arabidopsis) and Solanum lycopersicum (tomato). Application of G. rugosa extract to the root system by drenching tomato seedlings subjected to water deficit leads to improved CO2 assimilation and water use efficiency (WUEp), compared to mock-treated plants. These results highlight a new potential seaweed source of substances with osmoprotectant properties, useful for biostimulant development. Future studies may provide further insight into which components of the seaweed extract induce activation of the ABA pathway. [ABSTRACT FROM AUTHOR]

Recent studies have found increases in the cardiovascular mortality rates during poor air quality events due to outbreaks of desert dust. In Tenerife, we collected (2014–2017) data in 829 patients admitted with a heart failure diagnosis in the Emergency Department of the University Hospital of the Canaries. In this region, concentrations of PM10 and PM2.5 are usually low (~20 and 10 µg/m3), but they increase to 360 and 115 μg/m3, respectively, during Saharan dust events. By using statistical tools (including multivariable logistic regressions), we compared in-hospital mortality of patients with heart failure and exposure to PM10 and PM2.5 during dust and no-dust events. We found that 86% of in-hospital heart failure mortality cases occurred during Saharan dust episodes that resulted in PM10 > 50 µg/m3 (interquartile range: 71–96 µg/m3). A multivariate analysis showed that, after adjusting for other covariates, exposure to Saharan dust events associated with PM10 > 50 µg/m3 was an independent predictor of heart failure in-hospital mortality (OR = 2.79, 95% CI (1.066–7.332), p = 0.03). In conclusion, this study demonstrates that exposure to high Saharan dust concentrations is independently associated with in-hospital mortality in patients with heart failure. [ABSTRACT FROM AUTHOR]