LPEAT2 variant-specific mutations affects Camelina sativa phenotype under standard and temperature stress conditions

Genetic manipulations of Camelina sativa primarily focus on enhancing the quality and quantity of its oil, however, a crucial aspect of research should also include investigating its adaptability to environmental conditions, as this significantly impact seed yields. One such strategy is to study the role of acyl-CoA: lysophosphatidylethanolamine acyltransferases (LPEAT) involved in lipid metabolisms and plant development. Using the CRISPR-Cas9 method, C. sativa lines with disruption in the gene with dominant expression in its tissue CsLPEAT2B and additionally in CsLPEAT2C were generated. Under standard conditions, these lines were characterized by decreased intensity of phospholipid remodeling and reduced growth. Heat stress resulted in quite similar differences, whereas inverse phenotype was observed for lpeat2 plants subjected to cold, which fitness was boosted and expressed as accelerated development, intensified remodeling of membrane lipids, and elevated accumulation of osmoprotectants. Surprisingly, lpeat2 plants did not exhibit impaired core autophagy flux, however they showed more effective aggrephagy. Seeds of mutant lines showed an increase in total acyl-lipid and polyunsaturated fatty acid accumulation under standard conditions, as well as under low- and high-temperature stress. The duration of stress strongly affected the total seeds yield of both wild-type and mutant plants. The highest seed productivity was observed when both stresses occurred up to the bud development. Prolonged exposure to heat stress resulted in a drastic reduction in seed productivity and the production of deformed, nongerminating seeds. Long-term cold exposure reduced yield by half; however, lpeat2 seeds possess significantly higher amount of acyl-lipids and increased content of linolenic acids.