Morphological, Physiological, Biochemical, and Transcriptome Studies Reveal The Importance of Different Component Traits During Salinity Stress in Prunus

Abstract The almond crop has high economic importance on a global scale but its sensitivity to salinity stress can cause severe yield losses. Salt-tolerant rootstocks are vital for crop economic feasibility under saline conditions. Two commercial rootstocks submitted to salinity, and evaluated through different parameters, had contrasting results with the survival rates of 90.6% for ‘Rootpac 40’ (tolerant) and 38.9% for ‘Nemaguard’ (sensitive) under salinity (Electrical conductivity of water = 3 dS m− 1). Under salinity, ‘Rootpac 40’ accumulated less Na and Cl and more K in leaves than ‘Nemaguard’. Increased proline accumulation in ‘Nemaguard’ under salinity was an indicator of the high-stress levels compared to ‘Rootpac 40’. RNA-Seq analysis revealed a higher degree of differential gene expression was controlled by genotype rather than by treatment. Differentially expressed genes (DEGs) provided insight into the regulation of salinity tolerance in Prunus. DEGs associated with stress signaling pathways and transporters may play essential roles for salinity tolerance in Prunus. Some additional vital players involved in salinity stress in Prunus include CBL10, AKT1, KUP8, Prupe.3G053200 (chloride channel), and Prupe.7G202700 (mechanosensitive ion channel). Genetic components involved in salinity stress identified in this study may be explored to develop new rootstocks suitable for salinity-affected regions.