Changes in growth variables and potassium content in leaves of Black Barley in response to NaCl

Abstract

Much attention is being focused on the Black barley (Hordeum distichum L.) as a local cultivar offering good model for a cereal crop has traits of resistance to drought and salinity during vegetative growth stages. Although Black was sensitive to salt stress during germination, it developed gradual tolerance with age and proved very tolerant during growth and development stages. The data of study clearly revealed how this cultivar was superior over Arivat (Hordeum vulgare L.) in many physiological aspects such as leaf growth variables (i.e. rate and duration) and processes (i.e. cell division), tiller production and potassium content. Black barley had more tillers, faster rate and longer duration of growth processes which was accompanied with potassium accumulation, as sodium chloride concentration increased in the growth medium. Thus, the ability of Black cultivar to accumulate K + could have promoted growth variables (i.e. faster rate and longer duration of growth processes). Arivat, on the other hand, might have suffered from K + deficiency; which could explain the adverse effect of salt stress on leaf growth variables and processes. Moreover, the relative water content (RWC) and proline can clearly distinguish the two cultivars; RWC was higher and proline concentration was lower in leaves of Black as compared with Arivat. Therefore, Black barley proved efficient in maintaining growth, ion homeostasis, and might sacrifice less in growth under osmotic stress conditions. The possible mechanism of the effect of sodium chloride on potassium accumulation in Black barley is discussed.

Selection of Maize Genotypes with Tolerance to Osmotic Stress Associated with Salinity

“…One of the first symptoms of the deficiency of water in the tissues is the decrease of the RWC. However, there was no significant difference among the genotypes for the character [31]; instead, [32] detected differences. Due to this ambiguous behavior, RWC not be a reliable trait to identify tolerant genotypes.…”

Endophytes and Halophytes to Remediate Industrial Wastewater and Saline Soils: Perspectives from Qatar

“…In barley cultivars, Abu-Al-Basal and Yasseen [ 81 ] suggested two possible mechanisms to maintain optimal cytosolic K + /Na + ratio in the shoot tissues, and this can be achieved by either (1) restricting Na + accumulation in plant tissues or (2) preventing K + loss from the cell [ 82 , 83 ]. Moreover, early reports have shown active exchange of K + -Na + across the young tissues of some plants, such as barley [ 84 ]; low concentrations of K + salts around the root tissues induce rapid extrusion of major parts of Na + exchange for K + [ 85 ].…”

Ecophysiology of Wild Plants and Conservation Perspectives in the State of Qatar

“…However, these ions may be sequestered in vacuoles leaving relatively low ions in the cytoplasm. Some authors [55] reported in their review that crops including cereals tolerate NaCl by excluding Na + from the transpiration stream as well as sequestration of Na + and Cl -in the vacuoles of root and leaf cells, and promote other physiological processes like faster growth rates and longer duration by maintaining high concentrations in K + despite the osmotic stress of the salt outside the roots [28,56]. Organic solutes like glycinebetaine, proline, sugars, polyols etc., may accumulate in the cytoplasm to achieve osmotic balance inside the cells, and therefore play a pivotal role in plant cytoplasmic osmotic adjustment.…”