Search

Cysteine-rich polycomb-like protein (CPP-like) genes are a group of transcription factors with highly conserved cysteine-rich domains and are widely distributed in animals and plants, but do not present in yeast. Previous studies have shown that members of this family play important roles in the development of reproductive tissue and in the control of cell division in plants. In this study, whole genome identification of soybean CPP transcription factors was performed using bioinformatic methods. The results showed that there were 20 CPP transcription factors in the soybean genome, which encoded for 28 distinct CPP proteins. These transcription factors were distributed on 16 of 20 chromosomes. Phylogenetic relationship analysis showed that expression of CPP gene family members occurred before the differentiation of monocotyledons and dicotyledons. RNA-Seq analysis showed that 5 genes were highly expressed in all tissues, including Glyma10g39080, Glyma01g44670, Glyma101g66920, Glyma02g01540, and Glyma20g28740. One gene (Glyma14g14750) was specifically expressed in young leaves, while 2 genes (Glyma02g01540 and Glyma10g01580) were highly expressed in root nodules. Quantitative reverse transcriptase-polymerase chain reaction analysis revealed that the expression levels of most genes increased in the roots under high temperature stress. Our findings indicate that these genes are not only involved in growth and development, but also in the responses to high temperature stress in soybean roots.

Over-utilization of germplasms that are resistant to the soybean cyst nematode (SCN) in soybean breeding programs can lead to genetic vulnerability in resistant cultivars. Resistant wild soybean (Glycine soja) is considered an invaluable gene source for increasing the genetic diversity of SCN resistance. In this study, we genotyped 23 G. soja accessions that are resistant to SCN race 3 for polymorphisms in the resistance genes, rhg1, Rhg4, and SHMT, and investigated their genetic relationship with eight Glycine max resistant cultivars. We identified 89 single nucleotide polymorphisms (SNPs) and 11 DNA insertion-deletions (InDels), of which 70 SNPs and 8 InDels were found in rhg1, 9 SNPs were found in Rhg4, and 10 SNPs and 3 InDels were found in SHMT. Nucleotide diversity was π = 0.00238 and θ = 0.00235, and haplotype diversity was 1.000. A phylogenetic tree comprising four clusters was constructed using sequence variations of the 23 G. soja and 8 G. max resistant accessions. Five G. soja accessions in subcluster A2, and four G. soja accessions in cluster B were genetically distant from G. max genotypes. Eight resistance-associated SNPs in the three resistance genes formed nine haplotypes in total. G. soja resistant accessions had different haplotypes (H2, H4, H5, H6, H7, and H8) compared with those of G. max (H1, H3, and H9). These results provide vital information on the use of wild soybeans for broadening the genetic base of SCN resistance.