Identification and characterization of a temperature sensitive chlorotic soybean mutant

Abstract

AbstractScreening a transposon-mutagenized soybean population led to the discovery of a recessively inherited chlorotic phenotype. This “vir1” phenotype results in smaller stature, weaker stems, and a smaller root system with smaller nodules. Genome sequencing identified 15 candidate genes with mutations likely to result in a loss of function. Amplicon sequencing of a segregating population was then used to narrow the list to a single candidate mutation, a single-base change inGlyma.07G102300that disrupts splicing of the second intron. Single cell transcriptomic profiling indicates that this gene is expressed primarily in mesophyll cells and RNA sequencing data indicates it is upregulated in germinating seedlings by cold stress. Previous studies have shown that mutations toOs05g34040, the rice homolog ofGlyma.07G102300, produced a chlorotic phenotype that was more pronounced in cool temperatures. Growing soybean vir1 mutants at lower temperatures also resulted in a more severe phenotype. In addition, transgenic expression of wild typeGlyma.07G102300in the knockout mutant of the Arabidopsis homologAt4930720rescues the chlorotic phenotype, further supporting the hypothesis that the mutation inGlyma.07G102300is causal of the vir1 phenotype.