Adaptive mechanisms of tall wheatgrass to salinity and alkalinity stress

Abstract

Tall wheatgrass ‐Elymus elongatus (Host) Runemark‐ has long been used for forage production in temperate areas where salinity, alkalinity, waterlogging, or water scarcity hinder growth of other fodder species, and has a broad history of being included in revegetation programs of saline land and in wheat breeding programs. Despite its renown as a suitable species for unfavourable soil environments, the physiological mechanisms underlying its tolerance to abiotic stresses are scattered across the literature and this precludes answering the question that has motivated this review: how does tall wheatgrass endure inhospitable soil environments? The review starts with an outline of saline, alkaline and saline‐alkaline soils, and their associated waterlogging or water scarcity events. This is followed by a delineation of the physiological mechanisms responsible for plant tolerance to such soils, with an emphasis on the mechanisms associated with tall wheatgrass. Briefly outlined, tall wheatgrass has shown evidence of possessing mechanisms to allow the continuity of water influx ‐where salinity or drought leads to reduced water availability‐, strategies to avoid ion toxicity and to acquire essential nutrients, and ability to cope with high pH levels, waterlogging and excess reactive oxygen species produced as a consequence of stress. Seeking the answer to this inquiry, this review also contributes to the understanding of forage production and quality in these fragile soil environments.

Underlying Mechanisms of Action to Improve Plant Growth and Fruit Quality in Crops under Alkaline Stress

“…As previously mentioned, alkaline environments cause alterations in ionic homeostasis, and plants can extrude hydrogen ions (H + ) into the rhizosphere by means of proton pumps associated with the root plasma membrane (PM H + -ATPases -HAs) acidifying the rhizosphere zone, allowing nutrient uptake [59] to achieve an adequate ionic balance. Although Na + can enter through non-selective K + channels, the latter (K + ) tends to be translocated to the cytoplasm to generate osmotic regulation [54], thereby reducing toxicity and generating an adequate flow of water and nutrients [72].…”

Two‐cut system suggested for tall wheatgrass to balance herbage yield and quality in the coastal saline–alkaline land around the Bohai Sea

“…Thinopyrum ponticum (Podp.) Z. W. Liu & R. C. Wang, 2n = 10x = 70) is a perennial cool-season bunchgrass with tolerance to salt-alkali (Andrioli, 2023;Bazzigalupi et al, 2008;Bhuiyan et al, 2015Bhuiyan et al, , 2017Borrajo et al, 2022;Dewey, 1960;Grattan et al, 2004;Gu, 2004;Guo et al, 2015;Johnson, 1991;Mcguire & Dvôrák, 1981;Meng et al, 2009;Riedell, 2016;Rogers & Bailey, 1963;Roundy, 1983;Shannon, 1978;Shen et al, 1999;Steppuhn & Asay, 2005;Temel et al, 2015;Xu et al, 2020;B. Zhang et al, 2005;Zhang et al, 2008;R.…”

“…Zhang et al, 2022), drought (Bahrani et al, 2010;Borrajo et al, 2018Borrajo et al, , 2022Meng et al, 2011;Tian et al, 2022;Zhang et al, 2022), waterlogging (Bennett et al, 2019;Iturralde Elortegui et al, 2020;Vergiev, 2019), and diseases (Jia et al, 2022;Li & Wang, 2009;Zhang et al, 2021). It has long been used as a viable option in inhospitable soils, high in accumulation with salt and alkali, not suitable for other crops worldwide (Andrioli, 2023;Asay & Jensen, 1996). Tall wheatgrass originated from southern Europe and Asia Minor, from where it was introduced to North America, Australia, and South America in the 1950s (Andrioli, 2023;Asay & Jensen, 1996).…”

“…Z. W. Liu & R. C. Wang, 2 n = 10 x = 70) is a perennial cool‐season bunchgrass with tolerance to salt–alkali (Andrioli, 2023; Bazzigalupi et al, 2008; Bhuiyan et al, 2015, 2017; Borrajo et al, 2022; Dewey, 1960; Grattan et al, 2004; Gu, 2004; Guo et al, 2015; Johnson, 1991; Li, Li, et al, 2023; Mcguire & Dvôrák, 1981; Meng et al, 2009; Riedell, 2016; Rogers & Bailey, 1963; Roundy, 1983; Shannon, 1978; Shen et al, 1999; Steppuhn & Asay, 2005; Temel et al, 2015; Xu et al, 2020; B. Zhang et al, 2005; Zhang et al, 2008; R. Zhang et al, 2022), drought (Bahrani et al, 2010; Borrajo et al, 2018, 2022; Meng et al, 2011; Tian et al, 2022; Zhang et al, 2022), waterlogging (Bennett et al, 2019; Iturralde Elortegui et al, 2020; Vergiev, 2019), and diseases (Jia et al, 2022; Li & Wang, 2009; Zhang et al, 2021). It has long been used as a viable option in inhospitable soils, high in accumulation with salt and alkali, not suitable for other crops worldwide (Andrioli, 2023; Asay & Jensen, 1996). Tall wheatgrass originated from southern Europe and Asia Minor, from where it was introduced to North America, Australia, and South America in the 1950s (Andrioli, 2023; Asay & Jensen, 1996).…”

Acceptable Salinity Level for Saline Water Irrigation of Tall Wheatgrass in Edaphoclimatic Scenarios of the Coastal Saline–Alkaline Land around Bohai Sea

“…Tall wheatgrass (Elytrigia elongata (Host) Nevski = Thinopyrum ponticum (Podp.) Barkworth and D. R. Dewey (2n = 10x = 70)) is a perennial cool-season grass that confers tolerance to salt-alkali [7][8][9][10][11], drought [12][13][14], and waterlogging [15][16][17]. It has been widely cultivated in America, Australia, Argentina, Canada, and other European countries as a saline pasture or energy crop for more than half a century.…”