Wild barley Hordeum spontaneum (WB) is the progenitor of a cultivated barley Hordeum vulgare (CB). Understanding efficient mechanisms evolved by WB to cope with abiotic stresses may open prospects of transferring these promising traits to the high yielding CB genotypes. This study aimed to investigate the strategies that WB plants utilise in regard to the control of stomatal operation and ionic homeostasis to deal with salinity stress, one of the major threats to the global food security. Twenty-six genotypes of WB and CB were grown under glasshouse conditions and exposed to 300 mM NaCl salinity treatment for 5 weeks followed by their comprehensive physiological assessment. WB had higher relative biomass than CB when exposed to salinity stress. Under saline conditions, WB plants were able to keep constant stomatal density (SD) while SD significantly decreased in CB. The higher SD in WB also resulted in a higher stomatal conductance (g_s) under saline conditions, with g_s reduction being 51% and 72% in WB and CB, respectively. Furthermore, WB showed faster stomatal response to light, indicating their better ability to adapt to changing environmental conditions. Experiments with isolated epidermal strips indicated that CB genotypes have the higher stomatal aperture when incubated in 80 mM KCl solution, and its aperture declined when KCl was substituted by NaCl. On the contrary, WB genotype had the highest stomatal aperture being exposed to 80 mM NaCl suggesting that WB plants may use Na⁺ instead of K⁺ for stomata movements. Overall, our data suggest that CB employ a stress-escaping strategy by reducing stomata density, to conserve water, when grown under salinity conditions. WB, on a contrary, is capable of maintaining relatively constant stomata density, faster stomatal movement and higher g_s under saline conditions.

Item Type:	Refereed Article
Keywords:	cultivated barley (Hordeum vulgare), wild barley (Hordeum spontaneum), salinity stress, stomata density, stomatal conductance, sodium, potassium, barley, salinity
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Crop and pasture production
Research Field:	Agro-ecosystem function and prediction
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Grains and seeds
Objective Field:	Barley
UTAS Author:	Kiani-Pouya, A (Dr Ali Kiani-Pouya)
UTAS Author:	Rasouli, F (Ms Fatemeh Rasouli)
UTAS Author:	Zhou, M (Professor Meixue Zhou)
UTAS Author:	Shabala, S (Professor Sergey Shabala)
ID Code:	137712
Year Published:	2020 (online first 2019)
Web of Science® Times Cited:	23
Deposited By:	TIA - Research Institute
Deposited On:	2020-02-28
Last Modified:	2021-07-19
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