Salt tolerance mechanisms in three Irano-Turanian Brassicaceae halophytes relatives of Arabidopsis thaliana

Abstract

Salt tolerance mechanisms were studied in three Irano-Turanian halophytic species from the Brassicaceae ‎‎(Lepidium latifolium, L. perfoliatum and Schrenkiella parvula) and compared with the glycophyte Arabidopsis thaliana. According to seed germination under salt stress, L. perfoliatum was the most tolerant species, while L. latifolium and S. parvula were rather susceptible. Contrastingly, based on biomass production L. perfoliatum was more salt sensitive than the other two species. In S. parvula biomass was increased up to 2.8-fold by 100 mM NaCl; no significant growth reduction was observed even when exposed to 400 mM NaCl. Stable activities of antioxidative defense enzymes, nil or negligible accumulation of superoxide anion and hydrogen peroxide, as well as stable membrane integrity in the three halophytes revealed that no oxidative stress occurred in these tolerant species under salt stress. Proline levels increased in response to salt treatment. However, it contributed only by 0.3‒2.0% to the total osmolyte concentration in the three halophytes (at 400 mM NaCl) and even less (0.04%) in the glycophyte, A. thaliana (at 100 mM NaCl). Soluble sugars in all three halophytes and free amino acids pool in S. parvula decreased under salt treatment in contrast to the glycophyte, A. thaliana. The contribution of organic osmolytes to the total osmolyte pool increased by salt treatment in the roots, while decreased in halophyte and glycophyte, A. thaliana leaves. Interestingly, this reduction was compensated by a higher relative contribution of K in the leaves of the halophytes, but of Na in A. thaliana. Taken together, biomass data and biochemical indicators show that S. parvula is more salt tolerant than the two Lepidium species. Our data indicate that L. latifolium, as a perennial halophyte with a large biomass, is highly suitable for both restoration of saline habitats and saline agriculture.

Multiple paths lead to salt tolerance - pre-adaptation vs dynamic responses from two closely related extremophytes

“…These extremophytes, currently used as leading models to investigate genetic mechanisms underlying salt stress adaptation (Kazachkova et al, 2018), show salt resilient growth even at salinities reaching seawater strengths (Inan et al, 2004;Orsini et al, 2010;Kazachkova et al, 2018). While S. parvula is found near salt lakes in the Irano-Turanian region (Hajiboland et al, 2018;Tug et al, 2019), E. salsugineum has a wider distribution from coastal to inland saline fields in the northern temperate to sub-arctic regions including the United States, Canada, Russia, and China (Lee et al, 2016). Despite multiple studies highlighting some of the metabolomic and transcriptomic responses of the extremophytes to salt stress (Gong et al, 2005;Kazachkova et al, 2013;Oh et al, 2014;Lee et al, 2016;Prerostova et al, 2017), molecular phenotypes determining how both extremophytes have convergently achieved salt adapted growth unlike their salt stresssensitive relative, A. thaliana have not been explored.…”

Response of forage seed germination to saline solutions under controlled conditions

“…The excessive accumulation of ions, of Cl-or Na + in the soil solution, could be toxic for most species [12][13][14] . If have the ability to control the transport and absorption of Na + to the photosynthetic tissue, have the ability to tolerate salinity 15,16 , mainly in the germination stage, but also it is crucial in the beginning of development and growth 17,18 . Many species have tolerance to salts by polygenic inheritances, which have the ability to withstand osmotic and ionic stress at cellular level [19][20][21][22][23] .…”

Advances in salt tolerance molecular mechanism in tobacco plants

“…Furthermore, accumulating Fig. 1 A proposed model of molecular mechanism of tobacco in response to salt stress evidence suggests that miRNAs, key enzyme genes for sterol synthesis of Brassinol, hormonal regulation and resistance (R) genes play essential roles in both abiotic and biotic stress responses in tobacco plants [88][89][90][91].…”