Associate Professor University of South Carolina Aiken Aiken, South Carolina
Body of Abstract: Screening a transposon-mutagenized soybean population allowed for the discovery of a recessively inherited chlorotic phenotype. This “Yellow Leaf” phenotype results in smaller stature, weaker stems, and smaller root system with smaller nodules. Genome sequencing identified 15 candidate genes with mutations likely to result in loss of function. Amplicon sequencing of a segregating population was then used to narrow the list to a single candidate, a two-base pair change in Glyma.07G102300. Single cell expression analysis indicates that this gene is expressed primarily in mesophyll cells and the mutation disrupts the second intron splice site, resulting in an early frame shift. Previous studies have shown that mutations to TCD5 (Os05g34040), the rice homolog of Glyma.07G102300, produced a chlorotic phenotype that was more pronounced in cool temperatures. Growing the “Yellow Leaf” mutant at lower temperatures also resulted in a more severe phenotype. In addition, transgenic expression of Glyma.07G102300 in the knockout mutant of the Arabidopsis homolog At4930720 rescues the chlorotic phenotype, further supporting the hypothesis that the mutation in Glyma.07G102300 is causal of the “Yellow Leaf” phenotype.