Seeds primed with 5-aminolevulinic acid mitigated temperature and drought stresses of wheat at germination and early seedling growth

Abstract

Drought and temperature stresses are known as primary factors limiting germination and seedling growth. Seed priming with plant growth regulators is one of the popular approaches to minimize adverse environmental stresses. This study was carried out to examine the role of seed priming with 5-aminolevulinic acid (5-ALA) at different levels (0, 25, 50, and 100 mg L -1 ) in germination and seedling growth of three wheat (Triticum aestivum L.) 'Emam', 'Gomria', and 'Zakia' under high temperature and drought stresses using a range of temperatures (25, 30, and 35 ℃) and water potentials (0.0 and -0.5 MPa). Water uptake, germination and early seedling growth attributes were measured. Drought stress and high temperature decreased germination%, germination index, and shoot fresh weight by 39.2%, 35.4%, and 48.6%, respectively, as compared with 0.0 MPa and 25 ℃. Seeds of 'Zakia' primed with 50 mg L -1 5-ALA at -0.5 MPa, and 35 ℃ increased fresh and dry weights of the root by 19.8% and 68.4% relative to 0 mg L -1 . For interaction between variety and 5-ALA, the highest germination% (90.3%) was recorded in 'Emam' with 50 mg L -1 5-ALA. Treatment 100 mg L -1 5-ALA decreased mean germination time by 24.5% and 28.9% at 25 and 35 ℃, respectively; 50 mg L -1 5-ALA increased seedling vigor index by 16.3% as compared with 0.0 mg L -1 at -0.5 MPa and 35 ℃. The 5-ALA enhanced water imbibition of the three varieties under drought and temperature stresses. This study suggested that seed priming with 5-ALA is a possible way to mitigate the negative effects produced by drought and temperature stresses on germination and early seedling growth of wheat.

Neodymium Nitrate Improves the Germination of Aged Wheat Seeds by Increasing Soluble Substances and Activating Antioxidative and Metabolic Enzymes in Seeds

“…Some pretreatments are capable of partially restoring wheat seed vigor after stress. For example, 5-aminolevulinic acid pretreatment of seeds alleviates damage caused by drought and high temperatures in wheat seedlings [18]. Ultrasonic treatment of wheat seeds increases the content of γ-aminobutyric acid (GABA) and thus increases seed germinability and seedling vigor [19].…”