Research Advances on Molecular Mechanism of Salt Tolerance in Suaeda

Abstract

Plant growth and development are inevitably affected by various environmental factors. High salinity is the main factor leading to the reduction of cultivated land area, which seriously affects the growth and yield of plants. The genus Suaeda is a kind of euhalophyte herb, with seedlings that grow rapidly in moderately saline environments and can even survive in conditions of extreme salinity. Its fresh branches can be used as vegetables and the seed oil is rich in unsaturated fatty acids, which has important economic value and usually grows in a saline environment. This paper reviews the progress of research in recent years into the salt tolerance of several Suaeda species (for example, S. salsa, S. japonica, S. glauca, S. corniculata), focusing on ion regulation and compartmentation, osmotic regulation of organic solutes, antioxidant regulation, plant hormones, photosynthetic systems, and omics (transcriptomics, proteomics, and metabolomics). It helps us to understand the salt tolerance mechanism of the genus Suaeda, and provides a theoretical foundation for effectively improving crop resistance to salt stress environments.

Chromosome-scale genome sequence of Suaeda glauca sheds light on salt stress tolerance in halophytes

“…For instance, quinoa possesses epidermal bladder cells (EBCs), which are responsible for secreting salt out of the plant, resulting in its high salt-stress potential [ 13 ]. On the other hand, S. glauca does not have salt glands or bladders; instead, its leaves are succulent, and specialized parenchymatous tissue stores salt and water in giant vacuoles [ 17 ], suggesting that there might be a different salt-tolerance mechanism in S. glauca . Under salt stress, Suaeda species protect their cells by increasing osmoregulatory substances and enhancing their antioxidant system [ 17 , 18 ].…”

“…On the other hand, S. glauca does not have salt glands or bladders; instead, its leaves are succulent, and specialized parenchymatous tissue stores salt and water in giant vacuoles [ 17 ], suggesting that there might be a different salt-tolerance mechanism in S. glauca . Under salt stress, Suaeda species protect their cells by increasing osmoregulatory substances and enhancing their antioxidant system [ 17 , 18 ]. Carpobrotus rossii , on the other hand, stores salt ions in vacuoles to prevent leakage and this is crucial for its ability to deposit Na + , although the molecular regulation behind it is still not well understood [ 19 , 20 ].…”

Chloride Channel Family in the Euhalophyte Suaeda altissima (L.) Pall: Cloning of Novel Members SaCLCa2 and SaCLCc2, General Characterization of the Family

“…Genus Suaeda related to Amaranthaceae/Chenopodiaceae includes more than 100 species of herbaceous highly salt tolerant plants known as salt accumulating halophytes (euhalophytes) [ 1 , 2 ]. Various aspects of plant responses to salt stress are under investigation with the use of Suaeda plants at molecular-genetic and functional levels [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Some representatives of this genus such as S. salsa , S. maritima , S. fruticosa , S. altissima , and others have become good models for investigation of mechanisms underlying salt tolerance, particularly ionic regulation and compartmentation at the cell and whole plant levels, osmotic adjustment through biosynthesis of compatible solutes, antioxidant capacity regulation, transition to C 4 - and CAM-photosynthetic metabolism and others [ 3 , 4 , 5 , 6 , 7 , 8 ].…”

“…Some representatives of this genus such as S. salsa , S. maritima , S. fruticosa , S. altissima , and others have become good models for investigation of mechanisms underlying salt tolerance, particularly ionic regulation and compartmentation at the cell and whole plant levels, osmotic adjustment through biosynthesis of compatible solutes, antioxidant capacity regulation, transition to C 4 - and CAM-photosynthetic metabolism and others [ 3 , 4 , 5 , 6 , 7 , 8 ]. Intensively developing transcriptomics, genomics and proteomics in combination with functional studies of Suaeda plants are becoming a promising approach in developing strategies for increasing crop resistance to salt stress [ 9 ].…”

Analysis on the salt tolerance of Nitraria sibirica Pall. based on Pacbio full-length transcriptome sequencing

“…In addition, plants also alleviate salt stress by means of osmotic regulatory substances, antioxidant mechanisms, thickening cell wall structure and signal transduction (Zhao et al, 2020). However, there are some differences in salt tolerance mechanism among different halophytes (Li et al, 2020;Lv et al, 2017;Wei et al, 2022;Tiika et al, 2021;Li, 2008;Yu et al, 2022;Jin et al, 2016). The researches on N. sibirica under salt stress mainly focus on physiological ion balance (Tang et al, 2018), photosynthetic characteristics (Wang et al, 2018), reactive oxygen species metabolism (Zhao et al, 2021b) and seedling growth .…”