Karrikinolide Promotes Seed Germination but Has no Effect on Leaf Segment Senescence in Triticum aestivum L.

Abstract

Objective: Germination and senescence are the two most important developmental processes in the plant life cycle. While seed germination is an important physiological event for the continuity of species, leaf senescence is also an important developmental process that impacts crop yields. Karrikins are a group of plant growth regulators found in the smoke generated by burning plant material. It has been suggested that karrikinolide (KAR1) is generally the most active karrikin in terms of stimulating germination. Materials and Methods: In this study, the effect of karrikinolide on germination and leaf segment senescence in wheat was investigated. For this purpose, control, 1 nM, 0.01, 0.1, 1, and 10 μM KAR1 solutions were used. Firstly, the wheat seeds were germinated in the dark in these solutions and germination percentages and root lengths were measured. Secondly, 4 of first leaf segments (3cm. each) from 10-day-old wheat seedlings were placed in petri dishes containing 1, 10, 100 μM KAR1 and distilled water as a control. Following incubation, fresh weight, chlorophyll content, cell death amounts and total protein amounts were determined. Results: The obtained data shows that 1 μM KAR1 promotes germination and root length to the greatest extent. This suggests that karrikins have a promoting effect on the germination of wheat seeds. Our results demonstrate that KAR1 has no effect on leaf segment senescence. Conclusion:  Our study suggests that KAR1 has the potential to be used in agriculture to improve germination and seedling growth of crop species.