Contribution of two different Na+ transport systems to acquired salinity tolerance in rice

Acquired salinity tolerance in rice: Plant growth dataset

“…Seeds of twenty-nine rice varieties selected from the World Rice Core Collection [1] ( Table 1 ) were initially heat-sterilized at 60 °C for 10 min in a water bath, then surface-sterilized using 5% (v/v) sodium hypochlorite solution for 30 min, and finally rinsed thoroughly with distilled water. The seed germination process, seed transfer to Kimura-B nutrient solution, and the composition of the Kimura-B solution are provided in a related research article [2] . The nutrient solution was changed every 3 days, and the pH was maintained daily between 5.0–5.5.…”

The role of priming and memory in rice environmental stress adaptation: Current knowledge and perspectives

“…Based on the induction and recovery responses, rice landraces (Apo and Norungan, local rice cultivars developed through selective breeding; Ray et al, 2013) with elevated thermotolerance were identified (Vijayalakshmi et al, 2015). Rice varieties employ two Na + transport systems to acclimate to high salinity: the salinity-acclimatized Na + excluder OsHKT1;5 in the roots and the vacuolar Na + accumulator OsNHX1 in leaf blades (Figure 1a) (Sriskantharajah et al, 2020). Therefore, while analysing the salinity acclimation in rice, it is important to consider both mechanisms of Na + accumulation and exclusion.…”

“…Drought stress‐primed leaf blade tissue (green panel) shows increased ABA signalling (Auler et al, 2021; Li et al, 2019; Rossatto et al, 2023) and greater stomatal conductance (Auler et al, 2021). Salt stress‐priming increases activity of the vacuolar Na + /H + exchanger 1 (OsNHX1) within the leaf blade (Sriskantharajah et al, 2020), which transports Na + from cytosol into vacuoles reducing the salt‐induced toxicity during future stress. Salt stress‐primed root tissue shows increased activity of the Na + excluder, high‐affinity K + transporter 1;5 (OsHKT1;5), which imports Na + from xylem sap (dark brown panel) into the parenchyma cells in the root xylem (light brown panel), reducing the levels of harmful Na + in the photosynthetic tissues and increasing the Na + /K + ratio in the root (do Amaral et al, 2020a; Sriskantharajah et al, 2020).…”

“…Salt stress‐priming increases activity of the vacuolar Na + /H + exchanger 1 (OsNHX1) within the leaf blade (Sriskantharajah et al, 2020), which transports Na + from cytosol into vacuoles reducing the salt‐induced toxicity during future stress. Salt stress‐primed root tissue shows increased activity of the Na + excluder, high‐affinity K + transporter 1;5 (OsHKT1;5), which imports Na + from xylem sap (dark brown panel) into the parenchyma cells in the root xylem (light brown panel), reducing the levels of harmful Na + in the photosynthetic tissues and increasing the Na + /K + ratio in the root (do Amaral et al, 2020a; Sriskantharajah et al, 2020). The cold stress‐primed root displays increased activity of the aquaporin, plasma membrane intrinsic protein 2;5 (OsPIP2;5), which promotes the osmotic water flow into the root under subsequent severe cold stress (Ahamed et al, 2012).…”

Table_1.DOCX

“…For instance, overexpression of HKT1 has been shown to regulate the vertical distribution of Na + and K + , and export of Na + out of the xylem (Møller et al, 2009;Hauser and Horie, 2010). Induction of HKT1 in the roots and lower leaves has also been shown to reduce Na + concentration in the xylem sap, protecting the younger and more sensitive apical shoot meristems from toxic effects (Sunarpi et al, 2005;Davenport et al, 2007;Zhang et al, 2017;Liu et al, 2019;Sriskantharajah et al, 2020). Additionally, HKT1 has an important role in phloem loading by regulating the removal or recirculation Na + back to the roots (Berthomieu et al, 2003).…”