Foliar application of phytohormones enhances growth of maize and soybean seedlings

Phytohormones such as gibberellins, auxins and cytokinins are plant growth promoting factors which added to foliar fertilizers can modulate plant growth and development of agricultural species. This work was performed to study the effects of exogenously applied phytohormones both alone and in mixtures, on a legume and a cereal growing in chambers with controlled conditions of humidity, temperature and light/dark cycle. It was found that application of phytohormones resulted in a considerable increase in growth of soybean and maize plants. The mixture of phytohormones formulated with the lowest concentration of each required to enhance plant growth, allowed a significant improvement on several growth parameters involved in productivity. Thus, the addition of this mixture to commercial products as foliar fertilizers may render potential improvement of legume and cereal yields.Las fitohormonas tales como giberelinas, auxinas y citoquininas son compuestos promotores del crecimiento que, adicionados a fertilizantes foliares, podrían contribuir a mejorar el crecimiento y desarrollo de la planta. Este trabajo fue realizado para evaluar los efectos de la aplicación de fitohormonas exógenas, tanto solas como en mezclas, en leguminosas y gramíneas creciendo en cámaras con condiciones controladas de humedad, temperatura y ciclos de luz/oscuridad. La aplicación de fitohormonas ocasionó una considerable mejora en el crecimiento de plantas de soja y maíz. El formulado a base de la mezcla de fitohormonas, cada una en la concentración mínima requerida para lograr un efecto cuantificable, permitió mejorar significativamente las variables de crecimiento consideradas de importancia para aumentar la productividad. Así, la adición de esta mezcla de fitohormonas a productos comerciales utilizados como fertilizantes para aplicaciones foliares podría mejorar el crecimiento y rendimiento en leguminosas y gramíneas.Gerencia de Comunicación e Imagen Institucional, DNA SICC, INTAFil: Llanes, Analía. Universidad de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales. Laboratorio de Fisiología Vegetal; ArgentinaFil: Iparraguirre, Julia. Universidad de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales. Laboratorio de Fisiología Vegetal; ArgentinaFil: Masciarelli, Oscar. Universidad de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales. Laboratorio de Fisiología Vegetal; ArgentinaFil: María, N. Universidad de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales. Laboratorio de Fisiología Vegetal; ArgentinaFil: Luna, Maria Virginia. Universidad de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales. Laboratorio de Fisiología Vegetal; Argentin

Consequences and Mitigation Strategies of Heat Stress for Sustainability of Soybean (<em>Glycine max</em> L. Merr.) Production under the Changing Climate

Increasing ambient temperature is a major climatic factor that negatively affects plant growth and development, and causes significant losses in soybean crop yield worldwide. Thus, high temperatures (HT) result in less seed germination, which leads to pathogenic infection, and decreases the economic yield of soybean. In addition, the efficiency of photosynthesis and transpiration of plants are affected by high temperatures, which have negative impact on the physio-biochemical process in the plant system, finally deteriorate the yield and quality of the affected crop. However, plants have several mechanisms of specific cellular detection of HT stress that help in the transduction of signals, producing the activation of transcription factors and genes to counteract the harmful effects caused by the stressful condition. Among the contributors to help the plant in re-establishing cellular homeostasis are the applications of organic stimulants (antioxidants, osmoprotectants, and hormones), which enhance the productivity and quality of soybean against HT stress. In this chapter, we summarized the physiological and biochemical mechanisms of soybean plants at various growth stages under HT. Furthermore, it also depicts the mitigation strategies to overcome the adverse effects of HT on soybean using exogenous applications of bioregulators. These studies intend to increase the understanding of exogenous biochemical compounds that could reduce the adverse effects of HT on the growth, yield, and quality of soybean

Elevated CO₂ Concentration Improves Heat-Tolerant Ability in Crops

The rising concentration of atmospheric carbon dioxide (aCO2) and increasing temperature are the main reasons for climate change, which are significantly affecting crop production systems in this world. However, the elevated carbon dioxide (CO2) concentration can improve the growth and development of crop plants by increasing photosynthetic rate (higher availability of photoassimilates). The combined effects of elevated CO2 (eCO2) and temperature on crop growth and carbon metabolism are not adequately recognized, while both eCO2 and temperature triggered noteworthy changes in crop production. Therefore, to increase crop yields, it is important to identify the physiological mechanisms and genetic traits of crop plants which play a vital role in stress tolerance under the prevailing conditions. The eCO2 and temperature stress effects on physiological aspects as well as biochemical profile to characterize genotypes that differ in their response to stress conditions. The aim of this review is directed the open-top cavities to regulate the properties like physiological, biochemical, and yield of crops under increasing aCO2, and temperature. Overall, the extent of the effect of eCO2 and temperature response to biochemical components and antioxidants remains unclear, and therefore further studies are required to promote an unperturbed production system

Metabolomic profiling of the halophyte Prosopis strombulifera shows sodium salt- specific response

Primary and secondary metabolite profiles were analyzed in roots and leaves of the halophytic shrub Prosopis strombulifera in response to control plants (no salt added in the growing media) and to lowering the osmotic potential to 1.0, 1.9, and 2.6 MPa generated by NaCl, Na2SO4, and the iso-osmotic combination of them at 24 h after reaching such potential. A rapid production of metabolites in response to sodium salt was found, which was correlated with modifications in growth parameters. Analysis of polar metabolite profiles by GC-MS rendered a total of 108 significantly altered compounds including 18 amino acids, 19 secondary metabolites, 23 carbohydrates, 13 organic acids, 4 indole acids, among others. Primary metabolites showed a differential response under the salt treatments, which was dependent on salt type and concentration, organ and age of plants. Most of identified compounds showed the strongest accumulation at the highest salt concentration assayed for Na2SO4-treated plants, which was correlated with damaging effects of sulfate anion on plant growth. Roots of NaCl-treated plants showed a higher number of altered metabolites (analyzed by UPLC-ESI-QqTOF-MS) compared to other treatments, while leaves of Na2SO4-treated plants showed the highest number of altered signals. A low degree of overlapping between secondary metabolites altered in roots and leaves of NaCl and Na2SO4-treated plants was found. However, when both NaCl and Na2SO4 salts were present plants always showed a lower number of altered metabolites. Three compounds were tentatively identified: tryptophan, lysophosphatidylcoline and 13-hydroxyoctadecadienoic acid. Increasing knowledge on P. strombulifera metabolism will contribute to unravel the underlying biochemical mechanism of salt tolerance