AUTHOR=Fu Tiansi , Xu Chenyang , Li Hong , Wu Xiaohan , Tang Man , Xiao Binbin , Lv Ruili , Zhang Zhibin , Gao Xiang , Liu Bao , Yang Chunwu TITLE=Salinity Tolerance in a Synthetic Allotetraploid Wheat (SlSlAA) Is Similar to Its Higher Tolerant Parent Aegilops longissima (SlSl) and Linked to Flavonoids Metabolism JOURNAL=Frontiers in Plant Science VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.835498 DOI=10.3389/fpls.2022.835498 ISSN=1664-462X ABSTRACT=

Allotetraploidization between A and S (closely related to B) genome species led to the speciation of allotetraploid wheat (genome BBAA). However, the immediate metabolic outcomes and adaptive changes caused by the allotetraploidization event are poorly understood. Here, we investigated how allotetraploidization affected salinity tolerance using a synthetic allotetraploid wheat line (genome S^lS^lAA, labeled as 4x), its Aegilops longissima (genome S^lS^l, labeled as S^lS^l) and Triticum urartu (AA genome, labeled as AA) parents. We found that the degree of salinity tolerance of 4x was similar to its S^lS^l parent, and both were substantially more tolerant to salinity stress than AA. This suggests that the S^lS^l subgenome exerts a dominant effect for this trait in 4x. Compared with S^lS^l and 4x, the salinity-stressed AA plants did not accumulate a higher concentration of Na⁺ in leaves, but showed severe membrane peroxidation and accumulated a higher concentration of ROS (H₂O₂ and O₂^⋅⁣–) and a lesser concentration of flavonoids, indicating that ROS metabolism plays a key role in saline sensitivity. Exogenous flavonoid application to roots of AA plants significantly relieved salinity-caused injury. Our results suggest that the higher accumulation of flavonoids in S^lS^l may contribute to ROS scavenging and salinity tolerance, and these physiological properties were stably inherited by the nascent allotetraploid S^lS^lAA.