Abscisic acid (ABA) plays a crucial role in response to abiotic stress as important small molecules in regulating metabolism. This study aimed to evaluate the ability of foliar spraying ABA to regulate growth quality at rice seedling stage under salt stress. Results demonstrated that salt stress strongly reduced all the growth parameters of two rice seedlings (‘Chaoyouqianhao’ and ‘Huanghuazhan’), caused prominent decrease in the levels of photosynthetic pigments (mainly in Huanghuazhan), photosynthesis and fluorescence parameters. Salinity treatment increased the concentration of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in roots, whereas significant decreased H₂O₂was found in leaves of Huanghuazhan. Additionally, salinity triggered high Na⁺content particularly in leaves and enhanced catalase (CAT) activities, ascorbate peroxidase (APX) and peroxidase (POD) activities of the two rice seedlings. Nevertheless, salinity-induced increased root ascorbic acid (AsA) and glutathione (GSH) levels while decreased in leaves, which depended on treatment time. Conversely, ABA application partially or completely mitigated salinity toxicity on the seedlings. ABA could reverse most of the changed physiological parameters triggered by salt stress. Specially, ABA treatment improved antioxidant enzyme levels and significantly reduced the Na⁺content of two varieties as well as increased the K⁺, Mg²⁺and Ca²⁺content in leaves and roots. ABA treatment increased the hormone contents of 1-aminocclopropane carboxylic acid (ACC), trans-zeatin (TZ), N6-isopentyladenosine (IPA), Indole-3-acetic acid (IAA), and ABA in leaves of two rice varieties under salt stress. It is suggested that ABA was beneficial to protect membrane lipid peroxidation, the modulation of antioxidant defense systems and endogenous hormonal balance with imposition to salt stress.

Salt stress is a major factor limiting the growth and yield of soybean (Glycine max). Wild soybeans (Glycine soja) contain high allelic diversity and beneficial alleles that can be re-introduced into domesticated soybeans to improve adaption to the environment. However, very few beneficial alleles have been identified from wild soybean. Here, we demonstrate that wild soybean is more salt tolerant than cultivated soybean and examine dehydration responsive element-binding (DREB) family transcription factor genes to look for advantageous alleles that might improve drought tolerance in cultivated soybean. Our genome-wide analysis identified 103 DREB genes from the Glycine max genome. By combined RNA-sequencing and population genetics of wild, landrace, and cultivated soybean accessions, we show that the natural variation in DREB3a and DREB3b is related to differences in salt tolerance in soybean accessions. Interestingly, DREB3b, but not DREB3a, appears to have undergone artificial selection. Soybean plants carrying the wild soybean DREB3b allele (DREB3b^39Del) are more salt tolerant than those containing the reference genome allele (DREB3b^Ref). Together, our results suggest that the loss of the DREB3b^39Del allele through domestication of cultivated soybean may be associated with a reduction in salt tolerance. Our findings provide crucial information for improving salt tolerance in soybean through molecular breeding.

Brassinolide (BR) is a sterol compound, which can regulate plant seed germination, flowering, senescence, tropism, photosynthesis, stress resistance, and is closely related to other signaling molecules. This study aimed to evaluate the ability of soaking with BR to regulate growth quality at rice seedling stage under salt stress. Results demonstrated that salt stress increases the contents of ROS, MDA, Na⁺ and ABA, reduces the the SPAD value, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum fluorescence (Fm), variable fluorescence (Fv), the effective photochemical efficiency of PSII (Fv/Fo) and the maximum photochemical efficiency of PSII (Fv/Fm), reduces the biomass production and inhabits plant growth. All of these responses were effectively alleviated by BR soaking treatment. Soaking with BR could increase the activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and the contents of ascorbic acid, glutathione as well as soluble protein and proline, while BR soaking treatment inhibited the accumulation of ROS and reduced the content of MDA. BR soaking significantly reduced the contents of Na⁺ and increased the contents of K⁺ and Ca²⁺, indicating that soaking with BR is beneficial to the excretion of Na⁺, the absorption of K⁺ and Ca²⁺ and the maintenance of ion balance in rice seedlings under salt stress. BR also maintained endogenous hormone balance by increasing the contents of indoleacetic acid (IAA), zeatin (ZT), salicylic acid (SA), and decreasing the ABA content. Soaking with BR significantly increased the SPAD value, Pn and Tr and enhanced the Fm, Fv/Fm and Fv/Fo of rice seedlings under NaCl stress, protected the photosythetic system of plants, and improved their biomass. It is suggested that BR was beneficial to protect membrane lipid peroxidation, the modulation of antioxidant defense systems, ion balance and endogenous hormonal balance with imposition to salt stress.

Abscisic acid (ABA) has been shown to mitigate the deleterious effects of abiotic stresses and to regulate plant growth and development. Salinity is one of the important abiotic stresses affecting plant cell metabolism and physiology, which causes serious damages to crops. In this study, we investigated the protective role of exogenous ABA on leaves in response to salinity stress using rice seedlings (two leaf-one heart) subjected to three treatments: ZCK (control), ZS (50 mM NaCl), and ZSA (5 mg L^–1 ABA + 50 mM NaCl). We carried out transcriptomic and metabolomic analyses to identify the molecular mechanisms by which ABA protects plants against salt stress. Results showed that 1159 differentially expressed genes (DEGs) (916 up-regulated, 243 down-regulated) and 63 differentially accumulated metabolites (DAMs) (42 up-regulated, 21 down-regulated) were identified between the ZS and ZSA treatments, respectively. In addition, ABA pretreatment regulated the expression pattern of genes responsible for oxidation redox, starch and sucrose metabolism, and phenylpropanoid biosynthesis. The combined transcriptomic and metabolomic analysis revealed that 16 DEGs and 2 DAMs were involved in Flavonoid biosynthesis and 8 DEGs and 2 DAMs were involved alpha-Linolenic acid metabolism which are responsible for salinity stress tolerance through induced by exogenous ABA. Overall, ABA could enhance rice leaves growth and development mainly by regulating flavonoid biosynthesis and linoleic acid metabolism pathway.

Salt accumulation in arable lands causes significant abiotic stress, resulting in a 10% loss in global arable land area and jeopardizing food production and agricultural sustainability. In order to attain high and sustainable food production, it is imperative to enhance traditional agricultural practices with modern technology to enable the restoration of arable lands afflicted by salinity. This review consolidates recent rice-specific advancements aimed at enhancing salt stress resilience through integrated strategies. We explore the functions of primary and secondary metabolic pathways, organic amendments, microbial symbiosis, and plant growth regulators in reducing the negative impacts of salt. Furthermore, we highlight the significance of emerging genetic and epigenetic technologies, including gene editing and transcriptional regulation, in developing salt-tolerant rice cultivars. Physiological studies reveal salt stress responses in rice plants, biochemical analyses identify stress-related metabolites, microbial investigations uncover beneficial plant–microbe interactions, and molecular approaches enable the identification of key genes—together providing essential insights for developing salt-tolerant rice varieties. We present a comprehensive overview of the multilayered strategies—ranging from agronomic management and physiological adaptations to molecular breeding and microbial applications—that have been developed and refined over recent decades. These approaches have significantly contributed to understanding and improving salinity tolerance mechanisms in rice. This review provides a foundational framework for future research and practical implementation in stress-resilient rice farming systems.

The key function of plant growth regulators is to adjust the growth and development of plants to adapt to the changing environment, which plays a vital role in the growth and yield of crops. This study was aimed to evaluate the ability of foliar application of salicylic acid (SA) and abscisic acid (ABA) to regulate rice (Oryza sativa L.) growth quality at seedling stage and reproductive stage. The two rice cultivars Wanshengyoutianhong-4 (W4) and Huanghuazhan (HZ) were sprayed foliar with SA (100 mg L^-1) and ABA (4 mg L^-1) at two-leaf stage, and their effects on morphological growth, physiological characteristics, malondialdehyde (MDA), osmotic substances, protective enzyme activities, photosynthesis and yield components were studied. Results indicated that SA and ABA significantly increased morphological growth, osmotic substances, antioxidant enzyme activities; MDA content dropped significantly (p < 0.05) in W4. While the two regulators inhibited morphological growth and physiological characteristics in HZ. Additionally, net photosynthesis, stomatal conductance, transpiration rate, water use efficiency and apparent mesophyll conductance were improved in both of rice cultivars at heading stage as well as grain weight. In conclusion, foliar spray of SA and ABA enhanced plant growth, induced an increase in protective enzyme activities and reduced the oxidative damage of the hybrid rice cultivar but not of the conventional rice cultivar at seedling stage. Meanwhile, photosynthetic parameters and grain weight were slightly enhanced at reproductive stage. These results served as a theoretical basis and technical support for the chemical regulation and cultivation practices of rice.