title: Hormonal and metabolic regulation of source-sink relations under salinity and drought: from plant survival to crop yield stability.
abstract: Securing food production for the growing population will require closing the gap between potential crop productivity under optimal conditions and the yield captured by farmers under a changing environment, which is termed agronomical stability. Drought and salinity are major environmental factors contributing to the yield gap ultimately by inducing premature senescence in the photosynthetic source tissues of the plant and by reducing the number and growth of the harvestable sink organs by affecting the transport and use of assimilates between and within them. However, the changes in source-sink relations induced by stress also include adaptive changes in the reallocation of photoassimilates that influence crop productivity, ranging from plant survival to yield stability. While the massive utilization of -omic technologies in model plants is discovering hundreds of genes with potential impacts in alleviating short-term applied drought and salinity stress (usually measured as plant survival), only in relatively few cases has an effect on crop yield stability been proven. However, achieving the former does not necessarily imply the latter. Plant survival only requires water status conservation and delayed leaf senescence (thus maintaining source activity) that is usually accompanied by growth inhibition. However, yield stability will additionally require the maintenance or increase in sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves and to delayed stress-induced leaf senescence. This review emphasizes the role of several metabolic and hormonal factors influencing not only the source strength, but especially the sink activity and their inter-relations, and their potential to improve yield stability under drought and salinity stresses.
authors: Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura (C.E.B.A.S.), Consejo Superior de Investigaciones Científicas (C.S.I.C.), Campus Universitario de Espinardo, P.O. Box 164, E-30100 Murcia, Spain.
authors: Alfonso A
authors: AA
authors: Albacete
authors: Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura (C.E.B.A.S.), Consejo Superior de Investigaciones Científicas (C.S.I.C.), Campus Universitario de Espinardo, P.O. Box 164, E-30100 Murcia, Spain.
authors: Cristina
authors: C
authors: Martínez-Andújar
authors: Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura (C.E.B.A.S.), Consejo Superior de Investigaciones Científicas (C.S.I.C.), Campus Universitario de Espinardo, P.O. Box 164, E-30100 Murcia, Spain. Electronic address: alfocea@cebas.csic.es.
authors: Francisco
authors: F
authors: Pérez-Alfocea
mesh_terms: D018556:Crops, Agricultural / Q000378:metabolism / Q000502:physiology; D055864:Droughts; D010937:Plant Growth Regulators; D054712:Salinity; D013213:Starch / Q000378:metabolism; D013312:Stress, Physiological; D013395:Sucrose / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D013395:Sucrose; D013213:Starch
keywords: Assimilate transport; Biomass partitioning; Cytokinins; Fruit/grain filling; Gibberellins; Hormonal signaling; Invertases; Leaf senescence; Stay green; Sucrose and starch metabolism