Agro-Physiologic Responses and Stress-Related Gene Expression of Four Doubled Haploid Wheat Lines under Salinity Stress Conditions

Ibrahim Al-Ashkar; Walid Ben Romdhane; Rania A El-Said; Abdelhalim Ghazy; Kotb Attia; Abdullah Al-Doss

doi:10.3390/biology10010056

Agro-Physiologic Responses and Stress-Related Gene Expression of Four Doubled Haploid Wheat Lines under Salinity Stress Conditions

Biology (Basel). 2021 Jan 14;10(1):56. doi: 10.3390/biology10010056.

Authors

Ibrahim Al-Ashkar^{1

2}, Walid Ben Romdhane¹, Rania A El-Said³, Abdelhalim Ghazy¹, Kotb Attia^{4

5}, Abdullah Al-Doss¹

Affiliations

¹ Plant Production, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
² Agronomy Department, Faculty of Agriculture, Al-Azhar University, Cairo 11651, Egypt.
³ Biological and Ecological Department, Faculty of Home Economic, Al-Azhar University, Tanta 32514, Egypt.
⁴ Center of Excellence in Biotechnology Research, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
⁵ Rice Biotechnology Lab, Rice Research & Training Center, Field Crops Research Institute, Sakha, Kafr EL-Sheikh 33516, Egypt.

Abstract

Salinity majorly hinders horizontal and vertical expansion in worldwide wheat production. Productivity can be enhanced using salt-tolerant wheat genotypes. However, the assessment of salt tolerance potential in bread wheat doubled haploid lines (DHL) through agro-physiological traits and stress-related gene expression analysis could potentially minimize the cost of breeding programs and be a powerful way for the selection of the most salt-tolerant genotype. We used an extensive set of agro-physiologic parameters and salt-stress-related gene expressions. Multivariate analysis was used to detect phenotypic and genetic variations of wheat genotypes more closely under salinity stress, and we analyzed how these strategies effectively balance each other. Four doubled haploid lines (DHLs) and the check cultivar (Sakha93) were evaluated in two salinity levels (without and 150 mM NaCl) until harvest. The five genotypes showed reduced growth under 150 mM NaCl; however, the check cultivar (Sakha93) died at the beginning of the flowering stage. Salt stress induced reduction traits, except the canopy temperature and initial electrical conductivity, which was found in each of the five genotypes, with the greatest decline occurring in the check cultivar (Sakha-93) and the least decline in DHL2. The genotypes DHL21 and DHL5 exhibited increased expression rate of salt-stress-related genes (TaNHX1, TaHKT1, and TaCAT1) compared with DHL2 and Sakha93 under salt stress conditions. Principle component analysis detection of the first two components explains 70.78% of the overall variation of all traits (28 out of 32 traits). A multiple linear regression model and path coefficient analysis showed a coefficient of determination (R²) of 0.93. The models identified two interpretive variables, number of spikelets, and/or number of kernels, which can be unbiased traits for assessing wheat DHLs under salinity stress conditions, given their contribution and direct impact on the grain yield.

Keywords: abiotic stress-related genes; agro-physiologic traits; doubled haploid lines; multivariate analyses; salt tolerance; wheat.

Grants and funding

1442/Deanship of Scientific Research, King Saud University