The Effect of Smoke Treatment on the Germination of Four Species of Mesembryanthemum: Some Preliminary Observations

Abstract

In reaction to excessive salt and drought, the common ice plant, Mesembryanthemum crystallinum L. (Aizoaceae, Caryophyllales), shifts from C3 photosynthesis to Crassulacean acid metabolism (CAM). "Given the controversy over whether genetics or the environment play a greater role in M. crystallinum growth, it makes sense to give a high-level overview of the life cycle under laboratory settings. In order to characterize the first five stages of development using morphological, physiological, and molecular biological parameters, we aim to create a framework. The first two steps are germination and the development of the juvenile form, and they take place in a predictable order. Stages 3-5, when the plants would expand, bloom, and produce seeds absent the salt, are prevented from maturing into their full shape by early stresses. The third developmental stage is ambiguous under typical circumstances, but when CAM is expressed constitutively, environmental disturbances hasten maturation and flowering. Plants have already started to bloom, but they will soon wither and die from the ground up, leaving only their seed capsules and the salt they have stored in their enormous epidermal bladder cells in order to assure the survival of the human species (stage 5). This paper discusses salinity reactions that result in the compartmentalization of ions and compatible solutes, the maintenance of turgor, and CAM. This article concludes with a discussion of the genes and proteins encoded by those genes in the ice plant genome. Finally, we consider how each growth stage may be viewed as an ecological reaction to increasing stress. The enormous mass of plant material produced by the first, rigid juvenile phase is essential for the success of the indeterminate, mature phase. The degree to which this occurs depends on how severe the stress was, after which the fully mature form is driven toward flowering and seed set.