Effect of environmental complexity on salt-adaptation in Sorghum bicolor

Individual plants of Sorghum bicolor mature different adaptive reactions to salinity. The positive correlation between the frequency of specific reactions and the tolerance level of plants with that specific reaction results from adaptive determinism (AD). The effect of complexity in environmental conditions on AD in plants adapting for the first time to salinity, A0, and in their offspring A1 was compared. Environmental complexity increases when uncontrolled factors besides salinity affect plants. The diversity of reactions of plants correlates positively with environmental complexity. AD correlates negatively to environmental complexity in A1. In contrast, environmental complexity has no effect on AD in A0. A1 are more tolerant to salinity than A0: A1 inherited adaptive information. The likelihood that A1 plants are exposed to the same uncontrolled factor as their parent is low, and so the decrease of AD in A1 due to environmental complexity suggests that: (1) the information inherited is specific to saline conditions; (2) AD results mainly from inherited pre-existing information; plants react as informatively closed systems: saline conditions trigger the expression of an adaptive, pre-existing program. For A0, conclusions are: (1) the adaptive reaction is not an expression of pre-existing information; (2) AD emerges during the adaptation process: the environment imprints adaptively the plant’s development. In this case, plants react as open systems in terms of information.