5-Aminolevulinic Acid Improves Morphogenesis and Na+ Subcellular Distribution in the Apical Cells of Cucumis sativus L. Under Salinity Stress

Abstract

Soil salinity causes damage to plants and a reduction in output. A natural plant growth regulator, 5-aminolevulinic acid (ALA), has been shown to promote plant growth under abiotic stress conditions. In the present study, we assessed the effects of exogenously applied ALA (25 mg L−1) on the root architecture and Na+ distribution of cucumber (Cucumis sativus L.) seedlings under moderate NaCl stress (50 mmol L−1). The results showed that exogenous ALA improved root length, root volume, root surface area, and cell activity in the root tips, which were inhibited under salt stress. In addition, although salinity stress increased the subcellular Na+ contents, such as those of the cell wall, nucleus, plastid, and mitochondria, ALA treatment reduced these Na+ contents, except the soluble fraction. Molecular biological analysis revealed that ALA application upregulated both the SOS1 and HA3 transcriptional and translational levels, which suggested that the excretion of Na+ into the cytoplasm cloud was promoted by exogenous ALA. Meanwhile, exogenously applied ALA also upregulated the gene and protein expression of NHX1 and VHA-A under salinity stress, which suggested that the compartmentalization of Na+ to the vacuole was enhanced. Overall, exogenous ALA mitigated the damage caused by NaCl in cucumber by enhancing Na+ redistribution and increasing the cytoactivity of root cells.

Trehalose alleviates salt tolerance by improving photosynthetic performance and maintaining mineral ion homeostasis in tomato plants

“…Electron transport occurs primarily on the thylakoids of chloroplasts (Ma et al, 2018). At this point, salt stress caused separation of cytoplasmic wall and destruction of chloroplast structure, which was consistent with the results of Hameed et al (2021) and Wu et al (2021). Tre pretreatment could improve chloroplast damage of tomato plants under salt stress (Figure 4).…”

“…In addition, Wu (2018) displayed that NHX1 is a Na + , and K + /H + exchanger in the plasma membrane and intima, and it plays an important role in regulating pH and K + homeostasis and regulating the whole process from vesicle transport and cell expansion to plant development. However, ion transporters depend on the transmembrane H + concentration gradient (Wu et al, 2021). Plasma membrane H + -ATPase is the main driving force for the secondary active 10.3389/fpls.2022.974507 transport of mineral elements in plant cells, and the H + electrochemical potential gradient produced by its hydrolysis can transport Na + out of cells (Allakhverdiev et al, 1999).…”

Regulation of 5-Aminolevunilic Acid and Its Application in Agroforestry

“…Since heme is an important prosthetic group of respiratory enzymes, its content is associated with the respiration of germinating seeds. Up to now, the promotion of ALA on plant salt tolerance has been demonstrated in many species, such as watermelons [56], muskmelons [136], Pinus sylvestris, P. tabuliformis, and Amorpha fruticosa [137], lettuce [138], date palms [139], wheat [140], strawberries [141], oilseed rape [142], Perilla frutescens [143,144], sunflowers [145], cucumbers [146,147], Silybum marianum [57], grapes [148], rice [149], Swiss chard [150], tomatoes [151][152][153], peaches [154], Leymus chinensis [155], pumpkins [156], asparagus [157], Atropa belladonna [158], cauliflower [159], jujube [160,161], peanuts [162], Swiss chard [163], maize [164], Salvia miltiorrhiza [165], and Arundo donax [166].…”

Natural 5-Aminolevulinic Acid: Sources, Biosynthesis, Detection and Applications

“…It is reported that exogenous addition of a suitable concentration of 5-ALA can effectively alleviate weak light stress in tobacco seedlings (Li et al, 2019) and damages induced by UV-B in Cajanus cajan L. seedlings (Gupta and Prasad, 2021). Moreover, 5-ALA has shown a significant effect on alleviating abiotic stress caused by low temperature (Yan et al, 2020) and salinity (Islam et al, 2021;Wu et al, 2021) and so on in plants, which were summarized in detail in a recent review (Rhaman et al, 2021).…”