Investigation of changes in the profile of fatty acids and growth traits in response to waterlogging/flooding stress

Abstract

Abrupt climatic changes around the globe have brought serious challenges for agriculturally important crops due to increase in environmental temperature and frequent flooding/waterlogging events. Flooding acts as abiotic stress on plants by challenging the both growth and yield. Wheat is exposed to abiotic stresses such as flooding but its response is less studied. In the current study, Atta Habib, a local wheat variety, was analyzed for its response to flooding stress and post-flooding recovery. The lengths and weights of the roots and shoots, as well as the relative water content, ascorbate peroxidase activity, and fatty acid contents, were analyzed. Twenty-one days-old wheat seedlings were flooded for 7 days and then allowed to recover for 7 days following flooding removal. The lengths of the flooded shoots were retarded slightly to 15.62 cm as against 16.49 cm in age-matched control-1 seedlings (6% decrease). The weight in flooded shoots was measured as 199.37 mg, as against 212.27 mg in control-1 seedlings (6% decrease). Flooding retarded the root length to 12.99 cm that was 14.86 cm in control plants (14% decrease). Root weight was significantly reduced to 78.4 mg in flooded plants which was 138.33 mg in control plants (76% decrease). During post-flooding recovery stage, shoot length & weight were recovered to 4% and 7%, respectively as compared to flooded plants. Similarly, root length & weight showed 14% and 32% recovery, respectively during the post-flooding stage. Relative water content increased significantly to 92.38% in flooded shoots in comparison to control-1 seedlings. Ascorbate peroxidase activity was decreased by 11% in the post-flooding recovery stage. Linolenic acid content was 51.01% in control-1 plants, increased slightly to 56.82% in flooded wheat, and was reduced to 43.21% during recovery period. Palmitic acid was quantified as 34.54% in control-1, increased slightly to 34.95% in flooded seedlings, and increased noticeably to 37.76% during recovery. Linoleic acid (7.41%) and stearic acid (5.30%) were increased only during recovery. Oleic acid increased significantly in flooded (2.26%) and recovering seedlings (11.51%) in comparison to 0.95% and 2.60% in control-1 and control-2 seedlings, respectively. Alterations in growth parameters, ascorbate peroxidase activity, and fatty acids content reveals the adjustments in response to flooding stress, as a way to cope with the stress as shown by recovery trend; revealing that plants adjusted the analytes in post-flooding recovery stage. The adjustments in biochemicals under the flooding stress and during recovery point out their crucial role in flooding stress response. It is also proposed that future studies can be expanded with diverse germplasm and flooding stress durations to reveal more information.