Event Title
The Role of Late Embryogenesis Abundant (LEA) Protein 6 in Desiccation Tolerance in Arabidopsis thaliana Seeds
Description
PURPOSE: Seed development is divided into three major phases: morphogenesis, storage deposition, and maturation drying. During maturation drying, the seed loses water until it reaches approximately 10% moisture. At some point, the seed acquires the ability to tolerate this extreme water loss, possibly due to the accumulation of protective biomolecules such as Late Embryogenesis Abundant (LEA) proteins. In the genetic model organism, A. thaliana, there are 51 LEA proteins divided into seven groups based on the amino acid sequence. I wished to determine the involvement of one member of the Group 1 LEA proteins (“LEA6”) in desiccation tolerance (DT) by comparing the physiology of mutant seeds lacking the gene and those possessing the gene (wild type (WT)). METHODS AND MATERIALS: We compared the extent of germination of experimentally desiccated and non-desiccated mutant and WT seeds at varying time-points during maturation drying. ANALYSES: Germination data were analyzed using Kaplan-Meier analysis. RESULTS: We found that WT seeds become dependent on drying for germination during a window (14 to 16 days after anthesis) of maturation drying. Prior to this time, seeds cannot germinate quickly IF dried, but after this, seeds cannot germinate quickly if NOT dried. Mutant seeds lacking the LEA6 gene were delayed in acquiring this trait of “drying dependence”. CONCLUSIONS: LEA6 improves the rate of germination after but not before drying. Our results thus do not support the involvement of LEA6 in DT but suggest they play a role in the switch of seeds to drying dependence for germination during late maturation.
The Role of Late Embryogenesis Abundant (LEA) Protein 6 in Desiccation Tolerance in Arabidopsis thaliana Seeds
PURPOSE: Seed development is divided into three major phases: morphogenesis, storage deposition, and maturation drying. During maturation drying, the seed loses water until it reaches approximately 10% moisture. At some point, the seed acquires the ability to tolerate this extreme water loss, possibly due to the accumulation of protective biomolecules such as Late Embryogenesis Abundant (LEA) proteins. In the genetic model organism, A. thaliana, there are 51 LEA proteins divided into seven groups based on the amino acid sequence. I wished to determine the involvement of one member of the Group 1 LEA proteins (“LEA6”) in desiccation tolerance (DT) by comparing the physiology of mutant seeds lacking the gene and those possessing the gene (wild type (WT)). METHODS AND MATERIALS: We compared the extent of germination of experimentally desiccated and non-desiccated mutant and WT seeds at varying time-points during maturation drying. ANALYSES: Germination data were analyzed using Kaplan-Meier analysis. RESULTS: We found that WT seeds become dependent on drying for germination during a window (14 to 16 days after anthesis) of maturation drying. Prior to this time, seeds cannot germinate quickly IF dried, but after this, seeds cannot germinate quickly if NOT dried. Mutant seeds lacking the LEA6 gene were delayed in acquiring this trait of “drying dependence”. CONCLUSIONS: LEA6 improves the rate of germination after but not before drying. Our results thus do not support the involvement of LEA6 in DT but suggest they play a role in the switch of seeds to drying dependence for germination during late maturation.