Mutants are important experimental materials for plants to investigate genetics, physiology, and breeding. Mutations are mainly generated by spontaneous mutation, chemical mutagens, and physical mutagens. In this work, a mutant of Arabidopsis thaliana was induced by carbon ions accelerated by the Heavy Ion Research Facility in Lanzhou (HIRFL). In order to determine the fundamental discrepancies between the wild type (WT) and the mutant (M), a series of growth indexes and drought-tolerance-related physiological characteristics were analyzed.
The length of root and hypocotyls were analyzed by the Image J software on the 10th day after sowing. According to the measurement results, the average length of primary root and hypocotyls of mutant seedlings were 32.3% and 13.8% lower than those of WT seedlings, respectively. Water loss and proline accumulation are important factors that related to drought tolerance. The aboveground part of 4-week-old plants was detached from the underground part and weighed every 20 minutes. The proportion of fresh weight lost was calculated on the basis of the original weight of the plant. The mutant leaves showed a faster rate of water loss than WT leaves, implying reduced drought tolerance in the mutant plants. Proline accumulation is one of the common physiological responses in higher plants exposed to drought stress. After 72 hours of drought stress, proline accumulated dramatically in WT plants while the proline content of mutant plants showed no significant discrepancy, suggesting the descended proline accumulation ability which led to weak drought tolerance in mutant plants.