Transgenerational effects of temporal drought stress on spring barley morphology and functioning

Abstract

Drought stress affects plants leaving a long-lasting imprint that may be passed onto progeny, affecting its growth and functioning. The aim of the research was to analyse the transgenerational effect of intense drought on alterations in functioning and changes in the growth of shoot and roots of spring barley. Barley seeds from a maternal generation that were affected by intense drought stress at the flag leaf stage or grown in the optimum conditions throughout the vegetation period were used as a sowing material to analyse the growth of a progeny generation at drought or in soil at optimum soil moisture. The difference in water availability during the growth of the progeny generation significantly affected all measured indicators of plant growth and functioning. However, significant differences were also found between offspring growing in the same conditions but characterised by different water availability during the growth of the maternal generation. The differences between plants with different stress histories in the maternal generation were more pronounced in barley offspring grown at drought than at optimum soil water availability. The drought induced during the growth of the barley maternal generation decreased the shoot-to-root mass ratio, enhanced growth of thin roots, and reduced the number of thick roots in the progeny grown at drought, compared to plants that were grown in the same conditions but without drought in the maternal generation. Maintenance of relatively long roots at low allocation of biomass to roots at drought in the progeny of the stressed maternal generation may be an adaptive response that can minimise carbon cost of water and nutrient acquisition.The results obtained may have implications in the prediction of responses of crops and ecosystems to drought and in proper design of scientific experiments on plant responses to water availability.