Uncovering salt tolerance mechanisms in pepper plants: a physiological and transcriptomic approach.

[EN] Background Pepper is one of the most cultivated crops worldwide, but is sensitive to salinity. This sensitivity is dependent on varieties and our knowledge about how they can face such stress is limited, mainly according to a molecular point of view. This is the main reason why we decided to develop this transcriptomic analysis. Tolerant and sensitive accessions, respectively called A25 and A6, were grown for 14 days under control conditions and irrigated with 70 mM of NaCl. Biomass, different physiological parameters and differentially expressed genes were analysed to give response to differential salinity mechanisms between both accessions. Results The genetic changes found between the accessions under both control and stress conditions could explain the physiological behaviour in A25 by the decrease of osmotic potential that could be due mainly to an increase in potassium and proline accumulation, improved growth (e.g. expansins), more efficient starch accumulation (e.g. BAM1), ion homeostasis (e.g. CBL9, HAI3, BASS1), photosynthetic protection (e.g. FIB1A, TIL, JAR1) and antioxidant activity (e.g. PSDS3, SnRK2.10). In addition, misregulation of ABA signalling (e.g. HAB1, ERD4, HAI3) and other stress signalling genes (e.g. JAR1) would appear crucial to explain the different sensitivity to NaCl in both accessions. Conclusions After analysing the physiological behaviour and transcriptomic results, we have concluded that A25 accession utilizes different strategies to cope better salt stress, being ABA-signalling a pivotal point of regulation. However, other strategies, such as the decrease in osmotic potential to preserve water status in leaves seem to be important to explain the defence response to salinity in pepper A25 plants.This work was financed by the INIA (Spain) and the Ministerio de Ciencia, Innovacion y Universidades (RTA2017-00030-C02-00) and the European Regional Development Fund (ERDF). Lidia Lopez-Serrano is a beneficiary of a doctoral fellowship (FPI-INIA).Lopez-Serrano, L.; Calatayud, Á.; López Galarza, SV.; Serrano Salom, R.; Bueso Rodenas, E. (2021). Uncovering salt tolerance mechanisms in pepper plants: a physiological and transcriptomic approach. BMC Plant Biology. 21(1):1-17. https://doi.org/10.1186/s12870-021-02938-2S11721

Different Root Morphological Responses to Phosphorus Supplies in Grafted Pepper

Grafting technique is increasing thanks to its potential to produce plants more efficient and tolerant to biotic and abiotic stresses. Likewise, there is a growing interest in reducing inputs of fertilizers. The development of rootstocks suitable for low input agriculture is conditioned to the understanding of the changes on the root when facing such stresses. Our aim was to evaluate the morphological root response to Phosphorus (P) starvation of a rootstock selected for its good performance under low P conditions. Adige was grafted onto the selected rootstock and grown hydroponically in two different P concentrations, the selft-graft was done as control. Plants were then collected and analysed. Results showed that despite the differences in terms of P concentration among treatment the stress was not enough to cause a great biomass loss. However, there is evidence that individuals showed different root adaptations, modifiying root length, mass and volume, etc, under stress conditions, having the selected rootstock higher root length and volume under low P nutrient solutio

Physiological changes of pepper accessions in response to salinity and water stress

[EN] New sources of water stress and salinity tolerances are needed for crops grown in marginal lands. Pepper is considered one of the most important crops in the world. Many varieties belong to the genus Capsicum spp., and display wide variability in tolerance/sensitivity terms in response to drought and salinity stress. The objective was to screen seven salt/drought-tolerant pepper accessions to breed new cultivars that could overcome abiotic stresses, or be used as new crops in land with water and salinity stress. Fast and effective physiological traits were measured to achieve the objective. The present study showed wide variability of the seven pepper accessions in response to both stresses. Photosynthesis, stomatal conductance and transpiration reduced mainly under salinity due to stomatal and non-stomatal (Na+ accumulation) constraints and, to a lesser extent, in the accessions grown under water stress. A positive relationship between CO2 fixation and fresh weight generation was observed for both stresses. Decreases in Ys and YW and increased proline were observed only when accessions were grown under salinity. However, these factors were not enough to alleviate salt effects and an inverse relation was noted between plant salt tolerance and proline accumulation. Under water stress, A31 was the least affected and A34 showed the best tolerance to salinity in terms of photosynthesis and biomass.INIA, Spain (Project RTA2013-00022-C02-01 and doctoral fellowship FPI-INIA to LLS); European Regional Development Fund (ERDF)Lopez-Serrano, L.; Penella, C.; San Bautista Primo, A.; López Galarza, SV.; Calatayud, A. (2017). Physiological changes of pepper accessions in response to salinity and water stress. Spanish Journal of Agricultural Research. 15(3):1-10. https://doi.org/10.5424/sjar/2017153-11147S110153Abbad, H., El Jaafari, S., Bort, J., & Araus, J. L. (2004). Comparison of flag leaf and ear photosynthesis with biomass and grain yield of durum wheat under various water conditions and genotypes. Agronomie, 24(1), 19-28. doi:10.1051/agro:2003056Abideen, Z., Koyro, H.-W., Huchzermeyer, B., Ahmed, M. Z., Gul, B., & Khan, M. A. (2014). Moderate salinity stimulates growth and photosynthesis of Phragmites karka by water relations and tissue specific ion regulation. Environmental and Experimental Botany, 105, 70-76. doi:10.1016/j.envexpbot.2014.04.009Aktas, H., Abak, K., & Cakmak, I. (2006). Genotypic variation in the response of pepper to salinity. Scientia Horticulturae, 110(3), 260-266. doi:10.1016/j.scienta.2006.07.017Allen RG, Pereira RS, Raes D, Smith M, 1998. Crop evapotranspiration. In: Guidelines for computing crop water requirements - FAO Irrig Drain paper 56. Food and Agriculture Organization of the United Nations, Rome.Alvino, A., Centritto, M., & Lorenzi, F. (1994). Photosynthesis Response of Sunlit and Shade Pepper (Capsicum annuum) Leaves at Different Positions in the Canopy Under Two Water Regimes. Functional Plant Biology, 21(3), 377. doi:10.1071/pp9940377Bates, L. S., Waldren, R. P., & Teare, I. D. (1973). Rapid determination of free proline for water-stress studies. Plant and Soil, 39(1), 205-207. doi:10.1007/bf00018060Bojórquez-Quintal E, Velarde-Buendía A, Ku-González Á, Carillo-Pech M, Ortega-Camacho D, Echevaría-Machado I, Pottosin I, Martínez-Estévez M, 2014. Mechanisms of salt tolerance in habanero pepper plants (Capsicum chinense Jacq.): Proline accumulation, ions dynamics and sodium root-shoot partition and compartmentation. Front Plant Sci 5: 1-14.Bray EA, Bailey-Serres J, Weretilnyk E, 2000. Response to abiotic stress. In: Biochemistry and molecular biology of plants; Gruissem W, Buchannan B, Jones R (eds.). pp: 1158-1249. Am Soc Plant Physiol, Rockville, MD, USA.Callister, A. N., Arndt, S. K., & Adams, M. A. (2006). Comparison of four methods for measuring osmotic potential of tree leaves. Physiologia Plantarum, 127(3), 383-392. doi:10.1111/j.1399-3054.2006.00652.xChartzoulakis, K., & Klapaki, G. (2000). Response of two greenhouse pepper hybrids to NaCl salinity during different growth stages. Scientia Horticulturae, 86(3), 247-260. doi:10.1016/s0304-4238(00)00151-5CHAVES, M. M. (2002). How Plants Cope with Water Stress in the Field? Photosynthesis and Growth. Annals of Botany, 89(7), 907-916. doi:10.1093/aob/mcf105Chaves, M. M., Maroco, J. P., & Pereira, J. S. (2003). Understanding plant responses to drought — from genes to the whole plant. Functional Plant Biology, 30(3), 239. doi:10.1071/fp02076Chaves, M. M., Flexas, J., & Pinheiro, C. (2008). Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell. Annals of Botany, 103(4), 551-560. doi:10.1093/aob/mcn125Chen, Z., Cuin, T. A., Zhou, M., Twomey, A., Naidu, B. P., & Shabala, S. (2007). Compatible solute accumulation and stress-mitigating effects in barley genotypes contrasting in their salt tolerance. Journal of Experimental Botany, 58(15-16), 4245-4255. doi:10.1093/jxb/erm284Colmer, T. D., Munns, R., & Flowers, T. J. (2005). Improving salt tolerance of wheat and barley: future prospects. Australian Journal of Experimental Agriculture, 45(11), 1425. doi:10.1071/ea04162Cowan IR, Farquhar, G, 1977. Stomatal functioning in relation to leaf metabolism and environment. In: Integration of activity in the higher plants; Jennings DH (ed.). pp: 470-505. University Press, Cambrigde.Silva, E. N. da, Ribeiro, R. V., Ferreira-Silva, S. L., Viégas, R. A., & Silveira, J. A. G. (2011). Salt stress induced damages on the photosynthesis of physic nut young plants. Scientia Agricola, 68(1), 62-68. doi:10.1590/s0103-90162011000100010De Oliveira, A. B., Mendes Alencar, N. L., & Gomes-Filho, E. (2013). Comparison Between the Water and Salt Stress Effects on Plant Growth and Development. Responses of Organisms to Water Stress. doi:10.5772/54223De Pascale S, Ruggiero C, Barbieri G, 2003. Physiological responses of pepper to salinity and drought. J Am Sociol Hortic Sci 128: 48-54.Del Amor, F. M., Cuadra-Crespo, P., Walker, D. J., Cámara, J. M., & Madrid, R. (2010). Effect of foliar application of antitranspirant on photosynthesis and water relations of pepper plants under different levels of CO2 and water stress. Journal of Plant Physiology, 167(15), 1232-1238. doi:10.1016/j.jplph.2010.04.010Delfine, S., Tognetti, R., Loreto, F., & Alvino, A. (2002). Physiological and growth responses to water stress in Field-grown bell pepper (Capsicum annuumL.). The Journal of Horticultural Science and Biotechnology, 77(6), 697-704. doi:10.1080/14620316.2002.11511559Filippou, P., Bouchagier, P., Skotti, E., & Fotopoulos, V. (2014). Proline and reactive oxygen/nitrogen species metabolism is involved in the tolerant response of the invasive plant species Ailanthus altissima to drought and salinity. Environmental and Experimental Botany, 97, 1-10. doi:10.1016/j.envexpbot.2013.09.010Fischer KS, Wood G, 1981. Breeding and selection for drought tolerance in tropical maize. Proc. Symp. on principles and methods in crop improvement for drought resistance with emphasis on rice, IRRI, Philippines.Flexas, J., Bota, J., Loreto, F., Cornic, G., & Sharkey, T. D. (2004). Diffusive and Metabolic Limitations to Photosynthesis under Drought and Salinity in C 3 Plants. Plant Biology, 6(3), 269-279. doi:10.1055/s-2004-820867Gill, S. S., & Tuteja, N. (2010). Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants. Plant Physiology and Biochemistry, 48(12), 909-930. doi:10.1016/j.plaphy.2010.08.016Hasanuzzaman, M., Nahar, K., & Fujita, M. (2012). Plant Response to Salt Stress and Role of Exogenous Protectants to Mitigate Salt-Induced Damages. Ecophysiology and Responses of Plants under Salt Stress, 25-87. doi:10.1007/978-1-4614-4747-4_2Hassine, A. B., Ghanem, M. E., Bouzid, S., & Lutts, S. (2008). An inland and a coastal population of the Mediterranean xero-halophyte species Atriplex halimus L. differ in their ability to accumulate proline and glycinebetaine in response to salinity and water stress. Journal of Experimental Botany, 59(6), 1315-1326. doi:10.1093/jxb/ern040Huang, Y., Bie, Z., He, S., Hua, B., Zhen, A., & Liu, Z. (2010). Improving cucumber tolerance to major nutrients induced salinity by grafting onto Cucurbita ficifolia. Environmental and Experimental Botany, 69(1), 32-38. doi:10.1016/j.envexpbot.2010.02.002Lutts, S., & Guerrier, G. (1995). Peroxidase activities of two rice cultivars differing in salinity tolerance as affected by proline and NaCl. Biologia plantarum, 37(4). doi:10.1007/bf02908842Maynard DN, Hochmuth GJ, 2007. Knott's handbook for vegetable growers. John Wiley & Sons, Inc, NY.Morgan, J. (1992). Osmotic Components and Properties Associated With Genotypic Differences in Osmoregulation in Wheat. Functional Plant Biology, 19(1), 67. doi:10.1071/pp9920067Munns, R. (2002). Comparative physiology of salt and water stress. Plant, Cell & Environment, 25(2), 239-250. doi:10.1046/j.0016-8025.2001.00808.xMunns, R., & James, R. A. (2003). Screening methods for salinity tolerance: a case study with tetraploid wheat. Plant and Soil, 253(1), 201-218. doi:10.1023/a:1024553303144Munns, R., Brady, C., & Barlow, E. (1979). Solute Accumulation in the Apex and Leaves of Wheat During Water Stress. Functional Plant Biology, 6(3), 379. doi:10.1071/pp9790379Munns, R., & Tester, M. (2008). Mechanisms of Salinity Tolerance. Annual Review of Plant Biology, 59(1), 651-681. doi:10.1146/annurev.arplant.59.032607.092911Navarro, J. M., Garrido, C., Martínez, V., & Carvajal, M. (2003). Water relations and xylem transport of nutrients in pepper plants grown under two different salts stress regimes. Plant Growth Regulation, 41(3), 237-245. doi:10.1023/b:grow.0000007515.72795.c5Nio, S. A., Cawthray, G. R., Wade, L. J., & Colmer, T. D. (2011). Pattern of solutes accumulated during leaf osmotic adjustment as related to duration of water deficit for wheat at the reproductive stage. Plant Physiology and Biochemistry, 49(10), 1126-1137. doi:10.1016/j.plaphy.2011.05.011Noreen Z, Ashraf M, Akram NA, 2010. Salt-induced regulation of some key antioxidant enzymes and physio-biochemical phenomena in five diverse cultivars of turnip (Brassica rapa L.). J Agron Crop Sci 196: 273-285.Patade, V. Y., Bhargava, S., & Suprasanna, P. (2012). Halopriming mediated salt and iso-osmotic PEG stress tolerance and, gene expression profiling in sugarcane (Saccharum officinarum L.). Molecular Biology Reports, 39(10), 9563-9572. doi:10.1007/s11033-012-1821-7Patakas, A., Nikolaou, N., Zioziou, E., Radoglou, K., & Noitsakis, B. (2002). The role of organic solute and ion accumulation in osmotic adjustment in drought-stressed grapevines. Plant Science, 163(2), 361-367. doi:10.1016/s0168-9452(02)00140-1Penella C, Nebauer SG, Lopéz-Galarza S, San Bautista A, Gorbe E, Calatayud A, 2013. Evaluation for salt stress tolerance of pepper genotypes to be used as rootstocks. J Food Agric Environ 11: 1101-1107.Penella, C., Nebauer, S. G., Bautista, A. S., López-Galarza, S., & Calatayud, Á. (2014). Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: Physiological responses. Journal of Plant Physiology, 171(10), 842-851. doi:10.1016/j.jplph.2014.01.013Penella C, Nebauer SG, López-Galarza S, Bautista AS, Rodriguez-Burruezo A, Calatayud A, 2014b. Evaluation of some pepper genotypes as rootstocks in water stress conditions. Hort Sci 41: 192-200.Penella, C., Nebauer, S. G., Quiñones, A., San Bautista, A., López-Galarza, S., & Calatayud, A. (2015). Some rootstocks improve pepper tolerance to mild salinity through ionic regulation. Plant Science, 230, 12-22. doi:10.1016/j.plantsci.2014.10.007Penella, C., Landi, M., Guidi, L., Nebauer, S. G., Pellegrini, E., Bautista, A. S., … Calatayud, A. (2016). Salt-tolerant rootstock increases yield of pepper under salinity through maintenance of photosynthetic performance and sinks strength. Journal of Plant Physiology, 193, 1-11. doi:10.1016/j.jplph.2016.02.007Praxedes, S. C., De Lacerda, C. F., DaMatta, F. M., Prisco, J. T., & Gomes-Filho, E. (2009). Salt Tolerance is Associated with Differences in Ion Accumulation, Biomass Allocation and Photosynthesis in Cowpea Cultivars. Journal of Agronomy and Crop Science, 196(3), 193-204. doi:10.1111/j.1439-037x.2009.00412.xRouphael, Y., Cardarelli, M., Rea, E., & Colla, G. (2012). Improving melon and cucumber photosynthetic activity, mineral composition, and growth performance under salinity stress by grafting onto Cucurbita hybrid rootstocks. Photosynthetica, 50(2), 180-188. doi:10.1007/s11099-012-0002-1Saleem, A., Ashraf, M., & Akram, N. A. (2011). Salt (NaCl)-Induced Modulation in some Key Physio-Biochemical Attributes in Okra (Abelmoschus esculentus L.). Journal of Agronomy and Crop Science, 197(3), 202-213. doi:10.1111/j.1439-037x.2010.00453.xSmirnoff, N., & Cumbes, Q. J. (1989). Hydroxyl radical scavenging activity of compatible solutes. Phytochemistry, 28(4), 1057-1060. doi:10.1016/0031-9422(89)80182-7Szabados, L., & Savouré, A. (2010). Proline: a multifunctional amino acid. Trends in Plant Science, 15(2), 89-97. doi:10.1016/j.tplants.2009.11.009Tanjii KK, Kielen NC, 2002. Agricultural drainage water management in arid and semi-arid areas. FAO, Roma.Yadollahi, A., Arzani, K., Ebadi, A., Wirthensohn, M., & Karimi, S. (2011). The response of different almond genotypes to moderate and severe water stress in order to screen for drought tolerance. Scientia Horticulturae, 129(3), 403-413. doi:10.1016/j.scienta.2011.04.007Yoshiba, Y., Kiyosue, T., Nakashima, K., Yamaguchi-Shinozaki, K., & Shinozaki, K. (1997). Regulation of Levels of Proline as an Osmolyte in Plants under Water Stress. Plant and Cell Physiology, 38(10), 1095-1102. doi:10.1093/oxfordjournals.pcp.a02909

Pepper Rootstock and Scion Physiological Responses Under Drought Stress

[EN] In vegetables, tolerance to drought can be improved by grafting commercial varieties onto drought tolerant rootstocks. Grafting has emerged as a tool that copes with drought stress. In previous results, the A25 pepper rootstock accession showed good tolerance to drought in fruit production terms compared with non-grafted plants and other rootstocks. The aim of this work was to study if short-term exposure to drought in grafted plants using A25 as a rootstock would show tolerance to drought now. To fulfill this objective, some physiological processes involved in roots (rootstock) and leaves (scion) of grafted pepper plants were analyzed. Pepper plants not grafted (A), self-grafted (A/A), and grafted onto a tolerant pepper rootstock A25 (A/A25) were grown under severe water stress induced by PEG addition (-0.55 MPa) or under control conditions for 7 days in hydroponic pure solution. According to our results, water stress severity was alleviated by using the A25 rootstock in grafted plants (A/A25), which indicated that mechanisms stimulated by roots are essential to withstand stress. A/A25 had a bigger root biomass compared with plants A and A/A that resulted in better water absorption, water retention capacity and a sustained CO2 assimilation rate. Consequently, plants A/A25 had a better carbon balance, supported by greater nitrate reductase activity located mainly in leaves. In the non-grafted and self-grafted plants, the photosynthesis rate lowered due to stomatal closure, which limited transpiration. Consequently, part of NO3- uptake was reduced in roots. This condition limited water uptake and CO2 fixation in plants A and A/A under drought stress, and accelerated oxidative damage by producing reactive oxygen species (ROS) and H2O2, which were highest in their leaves, indicating great sensitivity to drought stress and induced membrane lipid peroxidation. However, drought deleterious effects were slightly marked in plants A compared to A/A. To conclude, the A25 rootstock protects the scion against oxidative stress, which is provoked by drought, and shows better C and N balances that enabled the biomass to be maintained under water stress for short-term exposure, with higher yields in the field.This work has funded by INIA (Spain) through Project RTA2017-00030-C02-00 and the European Regional Development Fund (ERDF). LL-S is a beneficiary of a doctoral fellowship (FPI-INIA).Lopez-Serrano, L.; Canet-Sanchis, G.; Selak, G.; Penella-Casañ, C.; San Bautista Primo, A.; López Galarza, SV.; Calatayud, A. (2019). Pepper Rootstock and Scion Physiological Responses Under Drought Stress. Frontiers in Plant Science. 10:1-13. https://doi.org/10.3389/fpls.2019.00038S11310. O. A., . N. O., & . Y. G. (2007). Effect of Grafting on Watermelon Plant Growth, Yield and Quality. Journal of Agronomy, 6(2), 362-365. doi:10.3923/ja.2007.362.365Aloni, B., Karni, L., Deventurero, G., Levin, Z., Cohen, R., Katzir, N., … Kapulnik, Y. (2008). POSSIBLE MECHANISMS FOR GRAFT INCOMPATIBILITY BETWEEN MELON SCIONS AND PUMPKIN ROOTSTOCKS. Acta Horticulturae, (782), 313-324. doi:10.17660/actahortic.2008.782.39Anjum, S. A., Farooq, M., Xie, X., Liu, X., & Ijaz, M. F. (2012). Antioxidant defense system and proline accumulation enables hot pepper to perform better under drought. Scientia Horticulturae, 140, 66-73. doi:10.1016/j.scienta.2012.03.028Asada, K. (1999). THE WATER-WATER CYCLE IN CHLOROPLASTS: Scavenging of Active Oxygens and Dissipation of Excess Photons. Annual Review of Plant Physiology and Plant Molecular Biology, 50(1), 601-639. doi:10.1146/annurev.arplant.50.1.601Ashraf, M., & Foolad, M. R. (2007). Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environmental and Experimental Botany, 59(2), 206-216. doi:10.1016/j.envexpbot.2005.12.006Borsani, O., Valpuesta, V., & Botella, M. A. (2003). Plant Cell, Tissue and Organ Culture, 73(2), 101-115. doi:10.1023/a:1022849200433Brand-Williams, W., Cuvelier, M. E., & Berset, C. (1995). Use of a free radical method to evaluate antioxidant activity. LWT - Food Science and Technology, 28(1), 25-30. doi:10.1016/s0023-6438(95)80008-5Cantero-Navarro, E., Romero-Aranda, R., Fernández-Muñoz, R., Martínez-Andújar, C., Pérez-Alfocea, F., & Albacete, A. (2016). Improving agronomic water use efficiency in tomato by rootstock-mediated hormonal regulation of leaf biomass. Plant Science, 251, 90-100. doi:10.1016/j.plantsci.2016.03.001CHOUKA, A., & JEBARI, H. (1999). EFFECT OF GRAFTING ON WATERMELON VEGETATIVE AND ROOT DEVELOPMENT, PRODUCTION AND FRUIT QUALITY. Acta Horticulturae, (492), 85-94. doi:10.17660/actahortic.1999.492.10Colla, G., Rouphael, Y., Leonardi, C., & Bie, Z. (2010). Role of grafting in vegetable crops grown under saline conditions. Scientia Horticulturae, 127(2), 147-155. doi:10.1016/j.scienta.2010.08.004Correia, M. J., Fonseca, F., Azedo-Silva, J., Dias, C., David, M. M., Barrote, I., … Osorio, J. (2005). Effects of water deficit on the activity of nitrate reductase and content of sugars, nitrate and free amino acids in the leaves and roots of sunflower and white lupin plants growing under two nutrient supply regimes. Physiologia Plantarum, 124(1), 61-70. doi:10.1111/j.1399-3054.2005.00486.xCuartero, J., Bolarín, M. C., Asíns, M. J., & Moreno, V. (2006). Increasing salt tolerance in the tomato. Journal of Experimental Botany, 57(5), 1045-1058. doi:10.1093/jxb/erj102Delfine, S., Tognetti, R., Loreto, F., & Alvino, A. (2002). Physiological and growth responses to water stress in Field-grown bell pepper (Capsicum annuumL.). The Journal of Horticultural Science and Biotechnology, 77(6), 697-704. doi:10.1080/14620316.2002.11511559DHINDSA, R. S., PLUMB-DHINDSA, P., & THORPE, T. A. (1981). Leaf Senescence: Correlated with Increased Levels of Membrane Permeability and Lipid Peroxidation, and Decreased Levels of Superoxide Dismutase and Catalase. Journal of Experimental Botany, 32(1), 93-101. doi:10.1093/jxb/32.1.93Estan, M. T. (2005). Grafting raises the salt tolerance of tomato through limiting the transport of sodium and chloride to the shoot. Journal of Experimental Botany, 56(412), 703-712. doi:10.1093/jxb/eri027Fahad, S., Bajwa, A. A., Nazir, U., Anjum, S. A., Farooq, A., Zohaib, A., … Huang, J. (2017). Crop Production under Drought and Heat Stress: Plant Responses and Management Options. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.01147Feller, U., & Vaseva, I. I. (2014). Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants. Frontiers in Environmental Science, 2. doi:10.3389/fenvs.2014.00039Ferrario, S., Valadier, M.-H., Morot-Gaudry, J.-F., & Foyer, C. (1995). Effects of constitutive expression of nitrate reductase in transgenic Nicotiana plumbaginifolia L. in response to varying nitrogen supply. Planta, 196(2). doi:10.1007/bf00201387Finckh, M. R. (s. f.). Integration of breeding and technology into diversification strategies for disease control in modern agriculture. Sustainable disease management in a European context, 399-409. doi:10.1007/978-1-4020-8780-6_19Flexas, J., Barón, M., Bota, J., Ducruet, J.-M., Gallé, A., Galmés, J., … Medrano, H. (2009). Photosynthesis limitations during water stress acclimation and recovery in the drought-adapted Vitis hybrid Richter-110 (V. berlandieri×V. rupestris). Journal of Experimental Botany, 60(8), 2361-2377. doi:10.1093/jxb/erp069Flexas, J., Bota, J., Loreto, F., Cornic, G., & Sharkey, T. D. (2004). Diffusive and Metabolic Limitations to Photosynthesis under Drought and Salinity in C 3 Plants. Plant Biology, 6(3), 269-279. doi:10.1055/s-2004-820867Garcı́a-Mata, C., & Lamattina, L. (2001). Nitric Oxide Induces Stomatal Closure and Enhances the Adaptive Plant Responses against Drought Stress. Plant Physiology, 126(3), 1196-1204. doi:10.1104/pp.126.3.1196Vahdati, K., & Lotfi, N. (2013). Abiotic Stress Tolerance in Plants with Emphasizing on Drought and Salinity Stresses in Walnut. Abiotic Stress - Plant Responses and Applications in Agriculture. doi:10.5772/56078Gilliham, M., Able, J. A., & Roy, S. J. (2017). Translating knowledge about abiotic stress tolerance to breeding programmes. The Plant Journal, 90(5), 898-917. doi:10.1111/tpj.13456Hageman, R. H., & Hucklesby, D. P. (1971). [45] Nitrate reductase from higher plants. Photosynthesis and Nitrogen Part A, 491-503. doi:10.1016/s0076-6879(71)23121-9Haroldsen, V. M., Szczerba, M. W., Aktas, H., Lopez-Baltazar, J., Odias, M. J., Chi-Ham, C. L., … Powell, A. L. T. (2012). Mobility of Transgenic Nucleic Acids and Proteins within Grafted Rootstocks for Agricultural Improvement. Frontiers in Plant Science, 3. doi:10.3389/fpls.2012.00039He, Y., Zhu, Z., Yang, J., Ni, X., & Zhu, B. (2009). Grafting increases the salt tolerance of tomato by improvement of photosynthesis and enhancement of antioxidant enzymes activity. Environmental and Experimental Botany, 66(2), 270-278. doi:10.1016/j.envexpbot.2009.02.007Heath, R. L., & Packer, L. (1968). Photoperoxidation in isolated chloroplasts. Archives of Biochemistry and Biophysics, 125(3), 850-857. doi:10.1016/0003-9861(68)90523-7Hsiao, T. C., & Xu, L. (2000). Sensitivity of growth of roots versus leaves to water stress: biophysical analysis and relation to water transport. Journal of Experimental Botany, 51(350), 1595-1616. doi:10.1093/jexbot/51.350.1595Jaworski, E. G. (1971). Nitrate reductase assay in intact plant tissues. Biochemical and Biophysical Research Communications, 43(6), 1274-1279. doi:10.1016/s0006-291x(71)80010-4Kaiser, W. M., & Huber, S. C. (2001). Post‐translational regulation of nitrate reductase: mechanism, physiological relevance and environmental triggers. Journal of Experimental Botany, 52(363), 1981-1989. doi:10.1093/jexbot/52.363.1981Keleş, Y., & Öncel, I. (2002). Response of antioxidative defence system to temperature and water stress combinations in wheat seedlings. Plant Science, 163(4), 783-790. doi:10.1016/s0168-9452(02)00213-3Özkum, D., & Tipirdamaz, R. (2010). Effects of l-Proline and Cold Treatment on Pepper (Capsicum annuum L.) Anther Culture. Survival and Sustainability, 137-143. doi:10.1007/978-3-540-95991-5_14Koevoets, I. T., Venema, J. H., Elzenga, J. T. M., & Testerink, C. (2016). Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance. Frontiers in Plant Science, 07. doi:10.3389/fpls.2016.01335Kumar, P., Rouphael, Y., Cardarelli, M., & Colla, G. (2017). Vegetable Grafting as a Tool to Improve Drought Resistance and Water Use Efficiency. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.01130Kyriacou, M. C., Rouphael, Y., Colla, G., Zrenner, R., & Schwarz, D. (2017). Vegetable Grafting: The Implications of a Growing Agronomic Imperative for Vegetable Fruit Quality and Nutritive Value. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.00741Lamaoui, M., Jemo, M., Datla, R., & Bekkaoui, F. (2018). Heat and Drought Stresses in Crops and Approaches for Their Mitigation. Frontiers in Chemistry, 6. doi:10.3389/fchem.2018.00026Lammerts van Bueren, E. T., Jones, S. S., Tamm, L., Murphy, K. M., Myers, J. R., Leifert, C., & Messmer, M. M. (2011). The need to breed crop varieties suitable for organic farming, using wheat, tomato and broccoli as examples: A review. NJAS - Wageningen Journal of Life Sciences, 58(3-4), 193-205. doi:10.1016/j.njas.2010.04.001Lee, J.-M., Kubota, C., Tsao, S. J., Bie, Z., Echevarria, P. H., Morra, L., & Oda, M. (2010). Current status of vegetable grafting: Diffusion, grafting techniques, automation. Scientia Horticulturae, 127(2), 93-105. doi:10.1016/j.scienta.2010.08.003Lexa, M., & Cheeseman, J. M. (1997). Growth and nitrogen relations in reciprocal grafts of wild-type and nitrate reductase-deficient mutants of pea (Pisum sativumL. var. Juneau). Journal of Experimental Botany, 48(6), 1241-1250. doi:10.1093/jxb/48.6.1241LI, H., LIU, S., YI, C., WANG, F., ZHOU, J., XIA, X., … YU, J. (2014). Hydrogen peroxide mediates abscisic acid‐induced HSP 70 accumulation and heat tolerance in grafted cucumber plants. Plant, Cell & Environment, 37(12), 2768-2780. doi:10.1111/pce.12360Lillo, C., Meyer, C., Lea, U. S., Provan, F., & Oltedal, S. (2004). Mechanism and importance of post-translational regulation of nitrate reductase. Journal of Experimental Botany, 55(401), 1275-1282. doi:10.1093/jxb/erh132Liu, S., Li, H., Lv, X., Ahammed, G. J., Xia, X., Zhou, J., … Zhou, Y. (2016). Grafting cucumber onto luffa improves drought tolerance by increasing ABA biosynthesis and sensitivity. Scientific Reports, 6(1). doi:10.1038/srep20212Loggini, B., Scartazza, A., Brugnoli, E., & Navari-Izzo, F. (1999). Antioxidative Defense System, Pigment Composition, and Photosynthetic Efficiency in Two Wheat Cultivars Subjected to Drought. Plant Physiology, 119(3), 1091-1100. doi:10.1104/pp.119.3.1091Martı́nez-Ballesta, M. C., Martı́nez, V., & Carvajal, M. (2004). Osmotic adjustment, water relations and gas exchange in pepper plants grown under NaCl or KCl. Environmental and Experimental Botany, 52(2), 161-174. doi:10.1016/j.envexpbot.2004.01.012Martinez-Rodriguez, M. M., Estañ, M. T., Moyano, E., Garcia-Abellan, J. O., Flores, F. B., Campos, J. F., … Bolarín, M. C. (2008). The effectiveness of grafting to improve salt tolerance in tomato when an ‘excluder’ genotype is used as scion. Environmental and Experimental Botany, 63(1-3), 392-401. doi:10.1016/j.envexpbot.2007.12.007Munns, R., Husain, S., Rivelli, A. R., James, R. A., Condon, A. G. T., Lindsay, M. P., … Hare, R. A. (2002). Avenues for increasing salt tolerance of crops, and the role of physiologically based selection traits. Progress in Plant Nutrition: Plenary Lectures of the XIV International Plant Nutrition Colloquium, 93-105. doi:10.1007/978-94-017-2789-1_7Navarro, J. M., Garrido, C., Martínez, V., & Carvajal, M. (2003). Water relations and xylem transport of nutrients in pepper plants grown under two different salts stress regimes. Plant Growth Regulation, 41(3), 237-245. doi:10.1023/b:grow.0000007515.72795.c5Orsini, F., Sanoubar, R., Oztekin, G. B., Kappel, N., Tepecik, M., Quacquarelli, C., … Gianquinto, G. (2013). Improved stomatal regulation and ion partitioning boosts salt tolerance in grafted melon. Functional Plant Biology, 40(6), 628. doi:10.1071/fp12350Penella, C., Landi, M., Guidi, L., Nebauer, S. G., Pellegrini, E., Bautista, A. S., … Calatayud, A. (2016). Salt-tolerant rootstock increases yield of pepper under salinity through maintenance of photosynthetic performance and sinks strength. Journal of Plant Physiology, 193, 1-11. doi:10.1016/j.jplph.2016.02.007Penella, C., Nebauer, S. G., López-Galarza, S., Quiñones, A., San Bautista, A., & Calatayud, Á. (2017). Grafting pepper onto tolerant rootstocks: An environmental-friendly technique overcome water and salt stress. Scientia Horticulturae, 226, 33-41. doi:10.1016/j.scienta.2017.08.020Penella, C., Nebauer, S. G., López-Galarza, S., SanBautista, A., Rodríguez-Burruezo, A., & Calatayud, A. (2014). Evaluation of some pepper genotypes as rootstocks in water stress conditions. Horticultural Science, 41(No. 4), 192-200. doi:10.17221/163/2013-hortsciPenella, C., Nebauer, S. G., Bautista, A. S., López-Galarza, S., & Calatayud, Á. (2014). Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: Physiological responses. Journal of Plant Physiology, 171(10), 842-851. doi:10.1016/j.jplph.2014.01.013Reddy, A. R., Chaitanya, K. V., & Vivekanandan, M. (2004). Drought-induced responses of photosynthesis and antioxidant metabolism in higher plants. Journal of Plant Physiology, 161(11), 1189-1202. doi:10.1016/j.jplph.2004.01.013Rivero, R. M., Ruiz, J. M., & Romero, L. (2003). Can grafting in tomato plants strengthen resistance to thermal stress? Journal of the Science of Food and Agriculture, 83(13), 1315-1319. doi:10.1002/jsfa.1541Rivero, R. M., Ruiz, J. M., Sánchez, E., & Romero, L. (2002). Does grafting provide tomato plants an advantage against H2 O2 production under conditions of thermal shock? Physiologia Plantarum, 117(1), 44-50. doi:10.1034/j.1399-3054.2003.1170105.xColla, G., Rouphael, Y., Cardarelli, M., Massa, D., Salerno, A., & Rea, E. (2006). Yield, fruit quality and mineral composition of grafted melon plants grown under saline conditions. The Journal of Horticultural Science and Biotechnology, 81(1), 146-152. doi:10.1080/14620316.2006.11512041Sade, N., Gebremedhin, A., & Moshelion, M. (2012). Risk-taking plants. Plant Signaling & Behavior, 7(7), 767-770. doi:10.4161/psb.20505Sairam, R. K., & Srivastava, G. C. (2001). Water Stress Tolerance of Wheat (Triticum aestivum L.): Variations in Hydrogen Peroxide Accumulation and Antioxidant Activity in Tolerant and Susceptible Genotypes. Journal of Agronomy and Crop Science, 186(1), 63-70. doi:10.1046/j.1439-037x.2001.00461.xSánchez-Rodríguez, E., Leyva, R., Constán-Aguilar, C., Romero, L., & Ruiz, J. M. (2014). How does grafting affect the ionome of cherry tomato plants under water stress? Soil Science and Plant Nutrition, 60(2), 145-155. doi:10.1080/00380768.2013.870873Sánchez-Rodríguez, E., Romero, L., & Ruiz, J. M. (2013). Role of Grafting in Resistance to Water Stress in Tomato Plants: Ammonia Production and Assimilation. Journal of Plant Growth Regulation, 32(4), 831-842. doi:10.1007/s00344-013-9348-2Sánchez-Rodríguez, E., Rubio-Wilhelmi, M. del M., Blasco, B., Leyva, R., Romero, L., & Ruiz, J. M. (2012). Antioxidant response resides in the shoot in reciprocal grafts of drought-tolerant and drought-sensitive cultivars in tomato under water stress. Plant Science, 188-189, 89-96. doi:10.1016/j.plantsci.2011.12.019Savvas, D., Colla, G., Rouphael, Y., & Schwarz, D. (2010). Amelioration of heavy metal and nutrient stress in fruit vegetables by grafting. Scientia Horticulturae, 127(2), 156-161. doi:10.1016/j.scienta.2010.09.011Savvas, D., Savva, A., Ntatsi, G., Ropokis, A., Karapanos, I., Krumbein, A., & Olympios, C. (2010). Effects of three commercial rootstocks on mineral nutrition, fruit yield, and quality of salinized tomato. Journal of Plant Nutrition and Soil Science, 174(1), 154-162. doi:10.1002/jpln.201000099Scheurwater, I. (2002). The contribution of roots and shoots to whole plant nitrate reduction in fast- and slow-growing grass species. Journal of Experimental Botany, 53(374), 1635-1642. doi:10.1093/jxb/erf008Schwarz, D., Rouphael, Y., Colla, G., & Venema, J. H. (2010). Grafting as a tool to improve tolerance of vegetables to abiotic stresses: Thermal stress, water stress and organic pollutants. Scientia Horticulturae, 127(2), 162-171. doi:10.1016/j.scienta.2010.09.016Sharp, R. E., Wu, Y., Voetberg, G. S., Saab, I. N., & LeNoble, M. E. (1994). Confirmation that abscisic acid accumulation is required for maize primary root elongation at low water potentials. Journal of Experimental Botany, 45(Special_Issue), 1743-1751. doi:10.1093/jxb/45.special_issue.1743Silva, C., Martinez, V., & Carvajal, M. (2008). Osmotic versus toxic effects of NaCl on pepper plants. Biologia plantarum, 52(1), 72-79. doi:10.1007/s10535-008-0010-yTardieu, F. (1998). Variability among species of stomatal control under fluctuating soil water status and evaporative demand: modelling isohydric and anisohydric behaviours. Journal of Experimental Botany, 49(90001), 419-432. doi:10.1093/jexbot/49.suppl_1.419Urban, L., Aarrouf, J., & Bidel, L. P. R. (2017). Assessing the Effects of Water Deficit on Photosynthesis Using Parameters Derived from Measurements of Leaf Gas Exchange and of Chlorophyll a Fluorescence. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.02068Velikova, V., Yordanov, I., & Edreva, A. (2000). Oxidative stress and some antioxidant systems in acid rain-treated bean plants. Plant Science, 151(1), 59-66. doi:10.1016/s0168-9452(99)00197-1Westgate, M. E., & Boyer, J. S. (1985). Osmotic adjustment and the inhibition of leaf, root, stem and silk growth at low water potentials in maize. Planta, 164(4), 540-549. doi:10.1007/bf00395973Yao, X., Yang, R., Zhao, F., Wang, S., Li, C., & Zhao, W. (2016). An analysis of physiological index of differences in drought tolerance of tomato rootstock seedlings. Journal of Plant Biology, 59(4), 311-321. doi:10.1007/s12374-016-0071-yYousfi, S., Serret, M. D., Márquez, A. J., Voltas, J., & Araus, J. L. (2012). Combined use of δ13C, δ18O and δ15N tracks nitrogen metabolism and genotypic adaptation of durum wheat to salinity and water deficit. New Phytologist, 194(1), 230-244. doi:10.1111/j.1469-8137.2011.04036.

SOX9 Triggers Different Epithelial to Mesenchymal Transition States to Promote Pancreatic Cancer Progression.

BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers mainly due to spatial obstacles to complete resection, early metastasis and therapy resistance. The molecular events accompanying PDAC progression remain poorly understood. SOX9 is required for maintaining the pancreatic ductal identity and it is involved in the initiation of pancreatic cancer. In addition, SOX9 is a transcription factor linked to stem cell activity and is commonly overexpressed in solid cancers. It cooperates with Snail/Slug to induce epithelial-mesenchymal transition (EMT) during neural development and in diseases such as organ fibrosis or different types of cancer. METHODS We investigated the roles of SOX9 in pancreatic tumor cell plasticity, metastatic dissemination and chemoresistance using pancreatic cancer cell lines as well as mouse embryo fibroblasts. In addition, we characterized the clinical relevance of SOX9 in pancreatic cancer using human biopsies. RESULTS Gain- and loss-of-function of SOX9 in PDAC cells revealed that high levels of SOX9 increased migration and invasion, and promoted EMT and metastatic dissemination, whilst SOX9 silencing resulted in metastasis inhibition, along with a phenotypic reversion to epithelial features and loss of stemness potential. In both contexts, EMT factors were not altered. Moreover, high levels of SOX9 promoted resistance to gemcitabine. In contrast, overexpression of SOX9 was sufficient to promote metastatic potential in K-Ras transformed MEFs, triggering EMT associated with Snail/Slug activity. In clinical samples, SOX9 expression was analyzed in 198 PDAC cases by immunohistochemistry and in 53 patient derived xenografts (PDXs). SOX9 was overexpressed in primary adenocarcinomas and particularly in metastases. Notably, SOX9 expression correlated with high vimentin and low E-cadherin expression. CONCLUSIONS Our results indicate that SOX9 facilitates PDAC progression and metastasis by triggering stemness and EMT

Polymorphism in sulfadimidine/4- aminosalicylic acid cocrystals: solid-state characterization and physicochemical properties

YesPolymorphism of crystalline drugs is a common phenomenon. However, the number of reported polymorphic cocrystals is very limited. In this work, the synthesis and solid state characterisation of a polymorphic cocrystal composed of sulfadimidine (SD) and 4- aminosalicylic acid (4-ASA) is reported for the first time. By liquid-assisted milling, the SD:4-ASA 1:1 form I cocrystal, the structure of which has been previously reported, was formed. By spray drying, a new polymorphic form (form II) of the SD:4-ASA 1:1 cocrystal was discovered which could also be obtained by solvent evaporation from ethanol and acetone. Structure determination of the form II cocrystal was calculated using high resolution X-ray powder diffraction. The solubility of the SD:4-ASA 1:1 cocrystal was dependent on the pH and predicted by a model established for a two amphoteric component cocrystal. The form I cocrystal was found to be thermodynamically more stable in aqueous solution than form II, which showed transformation to form I. Dissolution studies revealed that the dissolution rate of SD from both cocrystals was enhanced when compared to a physical equimolar mixture and pure SD.Science Foundation Ireland (SFI) under Grant Number 07/SRC/B1158 and SFI/12/RC/2275

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat