Small RNA variation between trifoliate and five-foliate shoot tips of Glycine max isolines

Two soybean isolines that differed in leaf phenotype were profiled by high throughput RNA and small RNA (sRNA) sequencing. A Clark isoline abbreviated as CF and homozygous for a dominant mutant allele, Lf1, that specifies a five-foliate compound leaf was compared to wild type Clark, designated CS, which is homozygous for the standard allele that produces trifoliate leaves. Although Lf1 is dominant, it presents variable expressivity as the young plantlets with the Lf1Lf1 genotype initially have trifoliate leaves in the first few weeks, after which they transition to five-foliate leaves. This study provides insight into the initial understanding of leaf development in soybean by revealing a number of small RNAs differentially expressed between the CS and CF. Out of over 200,000 unique sequences, 913 showed similarities to 122 known miRNAs in soybean. Small RNAs from shoot tips from two soybean isolines of Glycine max were compared: Clark standard trifoliate line (PI 547402, L58-231, abbreviated as CS) and Clark five-foliate (PI 547425, L64-1344, abbreviated as CF). These lines were obtained from the USDA Soybean Germplasm Collection GRIN (USDA/ARS, University of Illinois, Urbana IL).