Understanding the Molecular Basis of Salt Sequestration in Epidermal Bladder Cells of Chenopodium quinoa

Abstract

Highlights d HKT1-type channels mediate a one-way sodium load into quinoa bladder cells d ClC transporters operate in the Cl À sequestration into vacuoles of bladder cells d The bladder cytoplasm is osmotically balanced by potassium and proline import d On the transcript level, bladders are ''constitutively active'' for salt sequestration

Comparative physiological and biochemical mechanisms of salt tolerance in five contrasting highland quinoa cultivars

“…Moreover, quinoa plants tolerate saline conditions by dumping excess salt into specialised epidermal bladder cells on the leaves, which constitutively sequester and excrete them actively from metabolically active cells [10,43]. It is now becoming clear that the inward-rectifier highaffinity K + transporters (HKT1.2) is the underlying oneway accumulation system playing a key role for Na + load into bladder cells in quinoa [11]. This surplus salt, mainly Na + , compartmentalize from the leaf blades into the bladder hairs located on the leaf surfaces, from where it can be washed off by rain.…”

“…Among them, although it is well-known that salares landraces have the highest salinity tolerance, extent of salinity tolerance of the highland ecotype, growing at high altitudes around Titicaca Lake, has received less attention. Serving as a putative model halophytic crop, quinoa displayed a wide degree of variability in salinity tolerance strategies based on its genome [10,11]. Apart from the distinct anatomical features, i.e., salt bladders on both leaf adaxial and abaxial surfaces, salinity tolerance in quinoa plants was achieved through multiple strategies operating simultaneously, depending on the genetic background (ecotypes or genotypes) and the duration and intensity of the stress [12][13][14].…”

“…SOS1 controls the extrusion of Na + and is also involved in the transport processes implicated in the xylem and phloem loading/ unloading of Na + in plants (long-distance transport) [1]. NHX-type antiporters in the tonoplast, mediating the compartmentation of Na + in vacuoles, have a central role in establishing ion homeostasis and have been reported to increase the salt tolerance of various plants species [1,4,11]. Differential spatial and temporal expressions of these transporter genes synergistically regulate ion homeostasis by controlling Na + transport systems at the tissue-and whole-plant levels under salt conditions.…”

Systematic hormone-metabolite network provides insights of high salinity tolerance inPongamia pinnata(L.) pierre

“…The high correlation between hormones and cell-wall carbohydrates and organic acids may enhance the water permeability as well as pH regulation under salt tress conditions (Marriboina et al, 2017; Marriboina Attipalli, 2020a). The increased association of hormones with organic acids may provide immediate source of carbon energy and osmotic balance under salinity stress conditions (Assaha et al, 2017; Böhm et al, 2018; Yang Guo, 2018).…”

Dynamic measurement of cytosolic pH and [NO3-] uncovers the role of the vacuolar transporter AtCLCa in the control of cytosolic pH

“…In mammals, mutations in intracellular CLCs lead to severe genetic diseases affecting bones, kidneys and brain (1). In plants, CLCs regulate nutrient storage, photosynthesis and participate to drought and salt stress tolerance (4)(5)(6)(7)(8)(9)(10). In the last decades a wide number of studies addressed the biophysical properties of intracellular CLCs and provided a solid ground to understand the transport mechanisms of these exchangers (11)(12)(13)(14)(15).…”