Efficiency of Androgenesis In Vitro in the Culture of Isolated Winter Wheat Anthers: 3. The Influence of the Duration of Low-Temperature Pretreatment of Donor Plants on the Indole-3-Acetic Acid and Some Stress Hormones Levels in Flowers from Different Parts of the Spike

The work is devoted to studying the influence of the physiological state of inflorescences on the frequency of androclinic structures formation in the culture of isolated anthers of winter wheat (Triticum aestivum L.) variety Irkutskaya. Changes in the content of indole-3-acetic acid (IAA), abscisic acid (ABA), as well as jasmonic acid (JA) and salicylic acid (SA) in flower tissues during low-temperature pretreatment (4°C in the dark for 7 and 14 days) of isolated shoots were studied using chromatographic mass spectrometry method. An increased content of JA and SA was detected in flowers from the lower part of the spike already under control conditions. A simultaneous increase in the content of IAA, ABA and JA in the middle part of the inflorescence was shown after 7 days of low-temperature exposure. Based on the obtained data, it was suggested that ABA and JA signaling systems were involved in the process of switching genes responsible for the reprogramming of microspores. It is likely that IAA was the key factor in stabilizing the ABA content, what prevented critical damage to anther tissues. An increase in the SA content throughout the entire period of low-temperature exposure indicates its role in reducing the efficiency of androgenesis in vitro after 14 days of exposure due to its negative effect on the biosynthesis of IAA and JA. In the first and second parts of the our cycle works, an increase in the content of unsaturated fatty acids and changes in respiration activity were revealed in the process of low-temperature pretreatment of donor spikes of winter wheat. To summarize all data we can approve that the changes occurred in the flowers of winter wheat during the period of low-temperature pretreatment could only partly be attributed to the acclimation and resistance phases of low-temperature hardening. Isolation of shoots led to a decrease in the level of water-soluble carbohydrates and a rapid onset of the exhaustion phase, what was probably the reason for the decrease in the efficiency of androgenesis with an increase in the period of low-temperature treatment.