Salt-induced modulation in growth, photosynthetic capacity, proline content and ion accumulation in sunflower (Helianthus annuus L.)

Abstract

Salt-induced changes in growth, photosynthetic pigments, various gas exchange characteristics, relative membrane permeability (RMP), relative water content (RWC) and ion accumulation were examined in a greenhouse experiment on eight sunflower (Helianthus annuus L.) cultivars. Sunflower cultivars, namely Hysun-33, Hysun-38, M-3260, S-278, Alstar-Rm, Nstt-160, Mehran-II and Brocar were subjected to non-stress (0 mM NaCl) or salt stress (150 mM NaCl) in sand culture. On the basis of percent reduction in shoot biomass, cvs. Hysun-38 and Nstt-160 were found to be salt tolerant, cvs. Hysun-33, M-3260, S-278 and Mehran-II moderately tolerant and AlstarRm and Brocar salt sensitive. Salt stress markedly reduced growth, different gas exchange characteristics such as photosynthetic rate (A), water-use efficiency (WUE) calculated as A/E, transpiration rate (E), internal CO 2 concentration (C i ) and stomatal conductance (g s ) in all cultivars. The effect of 150 mM NaCl stress was non-significant on chlorophyll a and b contents, chlorophyll a/b ratio, RWC, RMP and leaf and root Cl -, K ? and P contents; however, salt stress markedly enhanced C i /C a ratio, free proline content and leaf and root Na ? concentrations in all sunflower cultivars. Of all cultivars, cv. Hysun-38 was higher in gas exchange characteristics, RWC and proline contents as compared with the other cultivars. Overall, none of the earlier-mentioned physiological attributes except leaf K ? /Na ? ratio was found to be effective in discriminating the eight sunflower cultivars as the response of each cultivar to salt stress appraised using various physiological attributes was cultivar-specific.

Triacontanol-induced Regulation in the Key Osmoprotectants and Oxidative Defense System of Sunflower Plants at Various Growth Stages under Salt Stress

“…Salinity-induced enhancement in free proline and glycinebetaine has been considered as an effective criterion for salt tolerance (Banu et al, 2010;Shahbaz et al, 2011). It is well documented that improved GB and free proline accumulation plays key role in shielding important enzymes, proteins and membranes, and scavenging ROS (Banu et al, 2010), water uptake (Hassine et al, 2010) and osmotic adjustment (Rhodes and Hanson, 1993;Banu et al, 2010).…”

Changes in the Mineralisation of Nutrients and Sunflower Biomass in Soil Irrigated with Water from Oil Exploration in a Semi-Arid Environment

“…Despite these variations in the soil being relatively wide for the type of water/treatment, only the levels of Na, Mg and lignin showed significant changes in the tissue. Variations in the levels of Na in the different types of water used for irrigation may be associated with the different levels of Na [32], Mg [33] and lignin [34] found in the sunflower tissue. These findings also underline the efficiency of the adopted treatments, as regards the presence of elements and the effect on the soil and plants, with a clear advantage seen with OPW, where their composition displays a reduction in levels.…”

Fluorescencia como indicador de estrés en <i>Helianthus annuus</i> L. Una revisión

“…La salinidad reduce el crecimiento, la fotosíntesis (Shahbaz et al, 2011) y el rendimiento del girasol. Aunque la resistencia o tolerancia a la salinidad depende del genotipo, en general una concentración superior a 100 mM de NaCl en el sustrato perjudica los procesos fisiológicos.…”

“…Aunque la resistencia o tolerancia a la salinidad depende del genotipo, en general una concentración superior a 100 mM de NaCl en el sustrato perjudica los procesos fisiológicos. La salinidad reduce la asimilación de CO 2 , la conductancia estomática, el contenido de K, el crecimiento de la raíz y la parte aérea y a su vez aumenta la acumulación de prolina, la concentración de Na y Cl, y la permeabilidad membranal (Saeed et al, 2009b;Shahbaz et al, 2011). Lo anterior reduce la producción de aquenios (Shahbaz et al, 2011).…”