Impact of Chilling on Growth and Hormonal Homeostasis of Triticum Aestivum and Triticum Spelta During Initial Stage of Vegetation and After Recovery

Abstract

The effect of short-term chilling (+4°C, 2 h) on hormonal homeostasis and growth parameters was investigated in 14-day-old stressed and 21-day-old recovered plants of Triticum aestivum cv 'Podolyanka' and T. spelta cv. 'Frankenkorn'. Short-term chilling didn't impact the linear indicators of wheat and spelt shoots and roots but stimulated shoot and root fresh and dry weight growth, while reducing root fresh weight. Spelt plants exhibited better post-stress recovery. Chilling led to a 396% increase in ABA content in wheat and a 74% increase in spelt. Stressed and recovered plants exceeded control plants in ABA content. Wheat exhibited three times higher constitutional SA content than spelt, while spelt exceeded wheat in gibberellins (GA 3 and GA 4 ) content. After chilling, SA content increased by 17.3% (wheat) and 18.7% (spelt), while gibberellins decreased by 32.4% (wheat) and 24.4% (spelt). Wheat dominated spelt in constitutional IAA content. Following chilling, IAA content decreased by 62% (wheat) and 72.2% (spelt). Our findings revealed both common characteristics and organ-and speciesspecific traits in phytohormones accumulation and balance in wheat and spelt plants during the rapid adaptation to chilling and subsequent recovery period. This will contribute to the understanding of how these related wheat species respond to chilling in the early stages of growth. Analyzing differences in constitutional and stress-induced endogenous phytohormone balances may be useful for developing screening methods for resilient genotypes and environmentally friendly technology of stress resistance induction.