Abstract
Salt stress has long been a prominent obstacle that restricts crop growth, and increasing the L-ascorbic acid (ASA) content of crops is an effective means of alleviating this stress. 2-Keto-L-gulonic acid (2KGA) is a precursor used in industrial ASA production as well as an ASA degradation product in plants. However, to date, no study has investigated the effects of 2KGA on ASA metabolism and salt stress. Here, we evaluated the potential of using 2KGA to improve crop resistance to salt stress (100mM NaCl) through a cultivation experiment of non-heading Chinese cabbage (Brassica campestris ssp. chinensis). The results showed that the leaf and root biomass were significantly improved by 2KGA application. The levels of metabolites and enzymes related to stress resistance were increased, whereas the hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents were decreased. Lipid peroxidation and cell membrane damage were alleviated following 2KGA treatment. Positive correlations were found between photosynthetic pigments and organic solutes, ASA and photosynthetic pigments, and ASA and antioxidant enzymes. In contrast, negative correlations were observed between antioxidant enzymes and H2O2/MDA. Moreover, the expression levels of L-gulono-1,4-lactone oxidase, GDP-mannose pyrophosphorylase, dehydroascorbate reductase-3, and ascorbate peroxidase were increased by 2KGA treatment. These results suggested that exogenous 2KGA application can relieve the inhibitory effect of salt stress on plant growth, and the promotion of ASA synthesis may represent a critical underlying mechanism. Our findings have significant implications for the future application of 2KGA or its fermentation residue in agriculture.
Highlights
Abiotic stress refers to specific environmental factors that are unfavorable for plant survival and development, such as high temperature, drought, and saline-alkali soils (Zandalinas et al, 2020)
L-ascorbic acid (ASA, vitamin C) is a non-enzymatic antioxidant commonly found in plants and plays a vital role in protecting plants from oxidative damage caused by abiotic stress
We found that salt stress significantly inhibited seedling growth
Summary
Abiotic stress refers to specific environmental factors that are unfavorable for plant survival and development, such as high temperature, drought, and saline-alkali soils (Zandalinas et al, 2020). Hydroponic agriculture with desalinated seawater is associated with the detrimental effects of salt stress (Santos et al, 2019) These observations highlight that saline-alkali soils or environments constitute key factors that restrict the sustainable development of agriculture. Liu et al (2013) demonstrated that, in tobacco, the knock-in of cDNA encoding L-galactose-1,4-lactone dehydrogenase (GLDH; EC 1.3.2.3), which catalyzes the conversion of L-galactono-1,4lactone to ASA, increased GLDH expression and ASA content, thereby enhancing salt stress tolerance in the plant. The application of exogenous ASA can increase the ASA content and salt stress resistance of plants (Shalata and Neumann, 2001) Despite these benefits of ASA, concerns regarding the use of genetically modified crops and the inherent instability of ASA have complicated their application in agriculture. The above evidence suggests that increasing the level of ASA can enhance the ability of plants to resist salt stress
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
