Differences in physiological and biochemical characteristics in response to single and combined drought and salinity stresses between wheat genotypes differing in salt tolerance

Abstract

The combined drought and salinity stresses pose a serious challenge for crop production, but the physiological mechanisms behind the stresses responses in wheat remains poorly understood. Greenhouse pot experiment was performed to study differences in genotype response to the single and combined (D + S) stresses of drought (4% soil moisture, D) and salinity (100 mM NaCl, S) using two wheat genotypes: Jimai22 (salt tolerant) and Yangmai20 (salt-sensitive). Results showed that salinity, drought and/or D + S severely reduces plant growth, biomass and net photosynthetic rate, with a greater effect observed in Yangmai20 than Jimai22. A notable improvement in water use efficiency (WUE) by 239, 77 and 103% under drought, salinity and D + S, respectively, was observed in Jimai22. Moreover, Jimai22 recorded higher root K concentration in drought and salinity stressed condition and shoot K under salinity alone than that of Yangmai20. Jimai22 showed lower increase in malondialdehyde (MDA) accumulation, but higher activities of superoxide dismutase (SOD, EC 1.15.1.1) and guaicol peroxidase (POD, EC 1.11.1.7), under single and combined stresses, and catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11) under single stress. Our results suggest that high tolerance of Jimai22 in both drought and D + S stresses is closely associated with larger root length, higher Fv/Fm and less MDA contents and improved capacity of SOD and POD. Moreover, under drought Jimai22 tolerance is firmly related to higher root K concentration level and low level of Na , high-net photosynthetic rate and WUE as well as increased CAT and APX activities to scavenge reactive oxygen species.

Varietal differences in physiological and biochemical responses to salinity stress in six finger millet plants

“…Root growth rate may be severely affected by saline soils and reduction may even be recorded in salt-tolerant plants. In agreement with previously published studies on the effects of salinity on root elongation (Cirillo et al, 2019; Dugasa et al, 2019), salinity treatments were found to cause stunted root growth. The growth-promoting effect under salinity stress could be due to an increase in the osmotic potential of the cells in the elongation zone coupled with enhanced cell division.…”

“…The resistance and response of plants to a salt stress varies according to its species or varieties or genotypes or variety and environment which could be attributed to the biological dissimilarities between the species or varieties or genotypes, plant growth, and composition and concentration of the salt stress conditions (Bertazzini et al, 2018; Filichkin et al, 2018; Shabala et al, 2013). Many reports have shown that short term salinity stress significantly affects the germination rate, seedling and root growth as well as ion composition, levels of relative water content, photosynthetic pigments, proline content, level of membrane lipid peroxidation as well as the amounts of reducing sugars and total protein (Dugasa et al, 2019; Sarabi et al, 2017; Kumar and Khare, 2016). These physiological and biochemical indices multivariate cluster analysis been used for classification of salt-sensitive and salt-tolerant varieties so that they can further be used in plant breeding programmes.…”

Assessment of changes in physiological and biochemical traits in four pistachio rootstocks under drought, salinity and drought + salinity stresses

“…In a similar way, drought stress besides causing water deficit and cell turgor loss, causes overproduction of highly reactive oxygen species (ROS) such as superoxide (O 2 − ), and hydrogen peroxide (H 2 O 2 ). This causes reduced growth, mineral shortages and photosynthetic imbalance (Dugasa et al ). The physiological and biochemical plants responses to the combination of drought and salinity are remarkable and cannot be directly assessed from the plants responses to single stress (Mittler ).…”

“…Therefore, salt‐tolerant rootstocks screening supplies an alternate origin to improve the breeding programs and applies them in order to try comprehend the pathways involved in the mechanism of salt tolerance (Akbari et al ). Besides environmental interactions mainly affecting tolerance to drought, various species, subspecies and crop cultivars under the same conditions show alternations in drought tolerance (Dugasa et al ). Thus, genetic diversity is a major fundamental factor in research associated with drought.…”

Transcriptomic Analysis of Betula halophila in Response to Salt Stress

“…Once the plant is under salt stress, multiple signal transduction pathways are activated to cope with salt stress [ 2 , 4 , 5 , 6 ]. In recent years, although extensive studies among ion uptake and transport, osmotic regulation, hormone metabolism, antioxidant metabolism, and stress signaling have made significant progress [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ], the molecular mechanisms involved in salt tolerance remain to be elucidated. In addition, next-generation high-throughput sequencing based RNA-seq analysis has been widely used to uncover expression patterns under abiotic stress, and it provides a comprehensive means of identifying and studying the differential expression genes [ 12 , 13 , 14 , 15 ].…”