Drought and high heat stresses modify Brassica napus L. leaf cuticular wax

Authors: Tomasi, Pernell; Luo, Zinan; Abdel-Haleem, Hussein

Submitted to: Plant Stress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2024
Publication Date: 6/10/2024
Citation: Tomasi, P., Luo, Z., Abdel-Haleem, H.A. 2024. Drought and high heat stresses modify Brassica napus L. leaf cuticular wax. Plant Stress. 13. Article 100513. https://doi.org/10.1016/j.stress.2024.100513.
DOI: https://doi.org/10.1016/j.stress.2024.100513

Interpretive Summary: Plants are facing multiple challenges to grow under unpredictable events of climate change, including drought and high heat events among other biotic and abiotic stresses. Both drought and high heat and their combination effects proved to dramatically affect plant growth and productivity. Breeding strategies to enhance stresses tolerance to individual stressors as well as combinations of stressors are required to cope with those effects. The current study was designed to study the effects of drought and heat stresses on accumulation of leaf waxes on Brassica napus, an important oilseed crop, to understand the mechanisms controlling leaf cuticular wax production in response to stress. Data showed variations in leaf wax accumulations in responses to drought and high heat stresses. Results demonstrated that leaf wax compositions and accumulation rates under studied stresses are genotype-dependent, thus suggesting choosing the specific parent(s) is an important factor for breeding for those stresses. Combination of drought and heat proved to have synergetic effects on specific brassica leaf waxes indicating the possibility to breed for both drought and heat tolerances in Brassica napus. Specific waxes showed abundance on the leaves of brassica plants grown under a combination of drought and heat stresses, suggesting them as potential candidates for improving the stress tolerance against those stressors.

Technical Abstract: Brassica napus L. is dual-purpose oilseed crop for food, feed and biofuel. Breeding for cultivars adapted to environmental stresses, especially drought and high heat stresses, is one of the strategies that has the attention of breeders. To evaluate the effects of those stresses on leaf wax accumulations, a replicated growth chamber experiment was designed to include three factors: drought (D), high heat (H) and genotypes (G). Data showed significant variations in leaf wax accumulations in response to those three factors and their combinations. For example, the accumulation of the C24 primary alcohol wax was affected by heat, drought, genotype, DxH, HxG, DxG and DxHxG, while the accumulation of the C16 fatty acid wax was affected by drought only. The results indicated that brassica leaf wax accumulation rates under those stresses are genotype dependent and suggest choosing specific parent(s) is an important factor for breeding for those stress factors. The C28 fatty acid, C29 primary alcohol and C30 alkane waxes showed abundance on brassica leaves grown under combination of drought and heat stresses, suggesting them as potential candidates for improving the stress tolerance against those intense stressors. Combination of drought and heat showed to have synergetic effects on specific brassica leaf waxes indicating the possibility to breed for both drought and heat tolerances in Brassica napus at the same time.