Corrigendum: Genetic Mapping of a Light-Dependent Lesion Mimic Mutant Reveals the Function of Coproporphyrinogen III Oxidase Homolog in Soybean.

[This corrects the article DOI: 10.3389/fpls.2020.00557.].

Genetic Mapping of a Light-Dependent Lesion Mimic Mutant Reveals the Function of Coproporphyrinogen III Oxidase Homolog in Soybean.

Lesion mimic mutants provide ideal genetic materials for elucidating the molecular mechanism of cell death and disease resistance. Here, we isolated a Glycine max lesion mimic mutant 2-1 (Gmlmm2-1), which displayed a light-dependent cell death phenotype. Map-based cloning revealed that GmLMM2 encods a coproporphyrinogen III oxidase and participates in tetrapyrrole biosynthesis. Knockout of GmLMM2 led to necrotic spots on developing leaves of CRISPR/Cas9 induced mutants. The GmLMM2 defect decreased the chlorophyll content by disrupting tetrapyrrole biosynthesis and enhanced resistance to Phytophthora sojae. These results suggested that GmLMM2 gene played an important role in the biosynthesis of tetrapyrrole and light-dependent defense in soybeans.

Evolution and Expression Divergence of the CYP78A Subfamily Genes in Soybean.

Gene expression divergence is an important evolutionary driving force for the retention of duplicate genes. In this study, we identified three CYP78A subfamily genes in soybean, GmCYP78A70, GmCYP78A57 and GmCYP78A72, which experienced different duplication events. GmCYP78A70 was mainly expressed in leaf tissue and the vegetative phase, whereas GmCYP78A57 was mainly expressed in floral tissue and seed, i.e., the reproductive phase. Expression of GmCYP78A72 could be detected in all the tissues and phases mentioned above. The expression levels of GmCYP78A70 and GmCYP78A57 in different soybean cultivars showed positive correlations with leaf size and 100-seed weight, respectively. The population genetics analysis indicated that the three genes had experienced different selective pressures during domestication and improved breeding of soybean. Deciphering the function of this subfamily of genes may well prove useful to breeders for improving soybean's agronomic traits.

Cloning of LjCYC1 gene and nuclear localization of LjCYC1 protein in Lotus japonicus.

The LjCYC1 (Lotus japonicus Cycloidea-like 1) gene, a homolog of CYC (Cycloidea) belonging to the TCP [TB1(teosinte branched 1), CYC, PCFs (PCF1 and PCF2)] gene family and encoding a predicted transcription factor and being proposed controlling different aspects of plant development, was isolated from the papilionaceous plant Lotus japonicus by screening the genomic DNA library, in order to test the functional conservation and divarication of CYC-like genes in legume. Sequence analyses indicate that LjCYC1 gene contains two exons and one intron and encodes a 370-AA peptide LjCYC1. The putative protein, LjCYC1, contains a TCP domain and an R domain, being a member of the CYC/TB1 subfamily of TCP family, and has 39.0% identity with and 42.6% similarity to CYC. LjCYC1-cDNA was cloned through RT-PCR. Different regions of the LjCYC1-cDNA were fused with the report gene GUS and then the fused constructs were transiently expressed in the onion epidermal cells through particle bombardment. Results of GUS and DAPI staining showed that the chimeric proteins with TCP domain were localized within the nucleus, confirming that LjCYC1 may act as a transcription factor. But the TCP domain itself could not confer the nuclear localization because the chimeric proteins with TCP domain alone were dispersed all over the transformed cells.