Resemblance and Difference of Seedling Metabolic and Transporter Gene Expression in High Tolerance Wheat and Barley Cultivars in Response to Salinity Stress.

Muhammad Zeeshan,Shama Naz,Fangbin Cao,Meiqin Lu,Feibo Wu,Shafaque Sehar

doi:10.3390/plants9040519

Muhammad Zeeshan, Shama Naz + Show 4 more

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https://doi.org/10.3390/plants9040519

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Abstract

To elucidate inter-specific similarity and difference of tolerance mechanism against salinity stress between wheat and barley, high tolerant wheat cv. Suntop and sensitive cv. Sunmate and tolerant barley cv. CM72 were hydroponically grown in a greenhouse with 100 mM NaCl. Glutathione, secondary metabolites, and genes associated with Na+ transport, defense, and detoxification were examined to discriminate the species/cultivar difference in response to salinity stress. Suntop and CM72 displayed damage to a lesser extent than in Sunmate. Compared to Sunmate, both Suntop and CM72 recorded lower electrolyte leakage and reactive oxygen species (ROS) production, higher leaf relative water content, and higher activity of PAL (phenylalanine ammonia-lyase), CAD (cinnamyl alcohol dehydrogenase), PPO (polyphenol oxidase), SKDH (shikimate dehydrogenase), and more abundance of their mRNA under salinity stress. The expression of HKT1, HKT2, salt overly sensitive (SOS)1, AKT1, and NHX1 was upregulated in CM72 and Suntop, while downregulated in Sunmate. The transcription factor WRKY 10 was significantly induced in Suntop but suppressed in CM72 and Sunmate. Higher oxidized glutathione (GSSG) content was accumulated in cv. CM72 and Sunmate, but increased glutathione (GSH) content and the ratio of GSH/GSSG were observed in leaves and roots of Suntop under salinity stress. In conclusion, glutathione homeostasis and upregulation of the TaWRKY10 transcription factor played a more important role in wheat salt-tolerant cv. Suntop, which was different from barley cv. CM72 tolerance to salinity stress. This new finding could help in developing salinity tolerance in wheat and barley cultivars.

Highlights

Salinity is one of the most common abiotic stresses constraining crop growth and productivity worldwide
Redox homeostasis at a cellular level regulated by a multi-system comprised of antioxidants and prooxidants is crucial for plant growth and development under biotic and abiotic stresses [2]
This study aimed to investigate the mechanisms that confer salinity tolerance in these two species by characterizing species level similarities or differences in glutathione homeostasis, secondary metabolism, and transporters genes upon exposure to salt stress

Summary

Introduction

Salinity is one of the most common abiotic stresses constraining crop growth and productivity worldwide. It is estimated that more than 50% of growing land will be affected as a result of mounted salinization in the soil by the year 2050 [1]. The most effective approach to dealing with salinization is developing crop varieties with tolerance. Lack of genetic resources well-adapted to salt stress and complexity of traits have hampered the progress toward breeding. In order to overcome these obstacles, it is important to identify and understand the mechanisms of tolerance for salt stress in existing different genetics resources. Redox homeostasis at a cellular level regulated by a multi-system comprised of antioxidants and prooxidants is crucial for plant growth and development under biotic and abiotic stresses [2]

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